NABU PC Black Screen, FAN Repair and Checks

Like a lot of other people I purchased one of the NABU Personal Computers that came up for sale in November. My Nabu arrived in December. It all looked good, when I turned it on there were two problems, the fan was making an awful noise and while I was getting a video signal it was a blank black screen. I opened the cover to look if something was out of place, and to check that fan. I pressed all the socketed ICs, reseated cables, tried other displays. Nothing helped and I didn’t feel it was worth shipping back. I mean even if scrapped I expect the computer was worth keeping.

I did inform the seller and he offered to send me another if I shipped it back. I decided to keep it in hopes of getting a second one, but there were none for sale. I kept looking back and recently he had some listed without the keyboard. I figured I probably had a working keyboard so I purchased a second one.

The new one came in and it worked with my monitor just fine. I was initially happy that the fan wasn’t making any noise, then I realized it wasn’t turning at all. I could hear that high pitch sound that likely indicated a stuck motor, which after opening it I found that was what was going on. We will get back to that later.

Now that I had a working Nabu I decided I would look at the other unit. The fan was noisy and I had pulled it back in December to check it. I connected it up to the monitor to see if it was in the same condition. It was still just displaying a black screen (it was powering on, and there was video signal), I didn’t realize it but looking at the LEDs on the front may have indicated if it was doing anything. Interestingly the fan was working much better, again I will get back to that later.

I found a guide to help trouble shoot the Nabu here: https://github.com/RudyRetroIntel/Vintage-Computer-Diagnostics

I have worked on a number of 80s era computers so there were a few things I was going to try. I started by pulling the power supply to get the fan detached to check it further. While I had the supply out, I checked it and reflowed some solder points on it. I didn’t see any issues with the power supply soldering, except I felt some pins were a little light on solder. I also polished all the connector pins on the power supply. They were pretty clean, but it was easy to do while it was out. I put the supply back in without the fan attached just for testing.

I pulled the mother board to get full access to it, and check the bodge wires on the bottom against the guide. It is the same revision of the board as in the guide, and has the same wires on the bottom (except different colors).

While I had it out I really don’t like that the LED board doesn’t have a connector on it. I put on a regular pin header and made a cable up and soldered that to the LED board and reinstalled it. Checking over the main board I didn’t find any issues. Before I reinstalled the mainboard though I rechecked the bodge wires, two of them had been pressed into and poked on component legs, I moved them and rechecked as I reinstalled the board.

Above you can see the LED Board with the original ribbon cable. I rewired it with a removable connector to make servicing the NABU easier in the future.

I pulled all the socketed ICs starting with the video generator ic. That IC had very tarnished legs. I take it that is due to the type of coating on that chip, I see that type of tarnish on IC and connectors and such. I used a fiberglass brush on the legs being sure to also do the inside of the legs. The IC Sockets on the Nabu look nice, but I still put a bit of contact cleaner into the socket before putting the IC back. I did the same with all of the other socketed chips. The video generator was the only IC that looked questionable.

On the left you see the video generator chip before cleaning, then the right is the chip after cleaning it.

After cleaning the ICs and reinstalling the board the Nabu was working properly. The fan still needs to be reinstalled but it all seemed to be working otherwise. They were tested before shipping out, so I expect it was a bad connection on some chip, possibly that one above.

The next thing to do was fix the fans on both of the computers. I was thinking about why the fan seemed to be working well on the first Nabu as it wasn’t before I took it apart in December. I figured it just freed up. Then looking it, it was still rubbing slightly. I pulled the fan from the Second Nabu, it wasn’t turning at all. I found the blades rubbed the outer frame just at the bottom. Looking at it closer I could tell there was no gap in the bottom and a wider gap at the top. The fan comes apart by taking out three small screws, this separates the motor from the frame.

The fans are very heavy. They are made of cast aluminum apparently, both the frame and the blades. They have been sitting so long, it seems the fan motor settled a little bit and slid down where the blades are now catching on the frame part. To correct this, you just have to take the three small screws loose on the back and get it properly centered again and reinstall them. There is very little clearance on these old German made fans. Modern fans are all plastic and many have far larger gaps between the blades and the frames. After doing this process with both fans they are properly centered again and moving freely without noise or any catching on the frames.

I reinstalled the fan and added a connector so that I can easily put it out off I have to in the future.

These computers do not appear mass produced. There is hand done work with the various cables and connectors. There are odd choices in assembly. The fans only have 3 screws holding them in, there are washers on the screws, flat washers glued to both sides of the fans, those locking washers glued to the top of that flat washer on the inside and a nut glued to that (which the glue has failed from removing them). The LED board on the front has spacers between it and the front frame. The fan has one connector that is removable, but the other one had a permanent splice crimp on it so it couldn’t be fully disconnected. The oddity that is the power cable from the power supply to the mainboard, which has no connector on that end either. The LED board being permanently soldered to the mainboard. That LED board is difficult to remove having to bend one or more of the LEDs to the side to get it out, possibly due to the LED leads being left so long do to having to use those spacers. It feels like they were designed and had some issues that were addressed, it would have been cool to see a “Rev 2” Nabu without the little oddities. I like the system, it is just a bit odd.

I look forward to using the Nabu. I guess at some point I may look at coming up with a keyboard for the second unit. I really like the Nabu Keyboard. I keep realizing I probably should have more pictures of these things working.

PSU Bottom, Reinforced Ground connector on the lower right corner.

Both of the NABU Power Supply Ground Lugs pushed off the pcb when reinstalling the ground wire to them. The pcb is a single sided board and has no through hole plating to keep it solid. The first one pushed and tore the copper the first time I went to put it back on, and I thought maybe it wasn’t solid or fully seated when it was put on originally. I pulled the power supply out and repaired it, by soldering some heavy wire around the pads and adjacent pin to reinforce it. Then tonight when getting the fan reinstalled into the second NABU the same thing happened to it. I know that one was soldered on well, as I had reworked the solder points on it and had even added solder to them. I pulled it back out again and did the same reinforcement with some heavy coper wire around the solder points. The picture above the ground connector is on the other side of the board there on the lower right corner. The two points from the lug holes and the one hole to the left of it are now all joined up with the wire in the solder. I was careful reinstalling the ground wire so as to not tear it free again from the copper. With that fixed and the fan reinstalled both of my NABUs are working now. I do only have one Keyboard, I’m wondering what it would take to build up a replacement keyboard. I would love to have had keyboards for both, but the current listing for them doesn’t include keyboards. I don’t see myself using both at once, I hate to keep a fully working unit as a spare parts machine though..

The second NABU worked perfectly out of the box, it had some rust along bottom of the back edge of the case top. I cleaned that up scraping away the worst of the rust, then used a fiberglass pen to get most of the rest. I then put some clear nail polish to protect the metal a bit. Beyond that I fixed the fan as described above, as it didn’t spin at all. The fan is now removable as I replaced the permanent crimp connection on the one lead with a connector. The system looked good otherwise and is working fine. I didn’t do any other modifications or changes to it. That unit is back in it’s box sitting on the storage shelves.

The other unit which was the one giving a black screen before pulling and cleaning all the socketed chips, I also fixed the fan on. It is the unit I put the removable connector on the front LED Panel. This was the first NABU I purchased, and it is the one with the matching keyboard so it will be the one I keep out to use. It also now has the fan removable with the detachable connector on the second wire on it.

Commodore 128 80 Column RGBI/CGA to RGB Analog Adapter Part 2

This is a follow up to an older project I did. The RGBI (RGB Digital) to RGBA (RGB Analog) for the Commodore 128 80 Column Video. Commodore’s RGBI is essentially the same as CGA so the adapter works on either. I made my prototype adapter back in 2019. I wanted a project to work on and wanted to work with KiCad to see how that went.

The Original Project: https://hobbytronics.home.blog/2019/10/08/commodore-128-80-column-rgbi-to-scart-to-hdmi/

I had started making a PCB Design in Eagle back in 2019, but I never finished it. I didn’t want to keep using Eagle so I stopped working on it.

This project is the RGBI to RGBA project packaged into a custom PCB Design and with a few additions. Such as a dedicated 5V DC Power Jack for when using it with an IBM Based pc for CGA.

It still has all the Commodore functions and more passthrough functions now for the Commodore 128. The Commodore specific parts could be skipped though.

Below are some pictures of the PCB Design work in progress.

3/4/23 the finished v1.3. Is ready to download.

The board is sized to fit into the same case I used for the prototype. The problem with that is you can not get it into the case with the DB ports soldered on. I still laid it out for that size and the mounting holes to match that case. I have a couple of them yet. I think it would probably be better to design a 3d printed case. I can make it split at the place I need to get it in and out easily that way.

The board layout is basically a DB9 port on the left side for the RGBI/CGA input. Along the top the first port is for a single RCA Port for 80 Column Monochrome output from the Commodore 128’s RGBI Port. It is there, so I figured it is easy to include. You don’t need an “adapter” to use the Monochrome output, it is just Pin7 on the RGBI DB9 port on the back of the C128, I am passing it through the 74LS244 buffer though. The next footprint is a SVideo Port for from the Commodore 40 Column from the AV Port, including a 300 Ohm resistor on the Chroma line. The next port along the top is for another RCA Port and it is the Commodore 40 Column Composite Video from the AV Port. The last port along the top is a third RCA Port which is the Audio Output from the Commodore AV Port. There along the right side is the 15 Pin RGB Analog Output. The bottom left has the 5V DC Barrel Jack footprint (Center Positive). The Header pins are the C64 AV Port, it is oversized as I want to make it “keyed” with a missing pin and a plugged hole in the connector. The CSync/HSync is to set the Sync output for the normal HSync pin on the VGA port to either be Combined Sync (CSync) or to just pass through the HSync normally. The Audio header is a jumper to either output the Audio to the RCA Port above it when in the Left side or to output it on the VGA port on Pin10 for when I use it with the SCART to HDMI Converter box. InvertSync is another jumper to Invert the CSync/HSync line if needed. Finally the SCART Blanking is a jumper to enable sending VCC/5V to Pin9 on the VGA Port again this is for when I use the adapter with the SCART to HDMI Converter box, this enables the SCART RGB Detection on SCART Pin 16.

I think it is a reasonably sized board. If it was to be used for CGA with an IBM Computer then you can install the Power Jack, and omit the 3 RCA Ports, the Mini Din Svideo Port and the 10 Pin Header for the Commodore AV Port. If it is going to be used for a Commodore 128 RGBI, just build the whole thing minus the Power Jack. I think the only thing with the power Jack is that plugging it in while having the Commodore AV Port connected could end up very bad. I might think about that a bit more if the 3pin Barrel jack could be setup to bypass the AV Port power or something like that.

I did go with through hole for the ICs, headers and ports. I was thinking of going with dual footprints for the Resistors and Capacitors to allow either through hole or surface mount parts. The Surface Mount capacitors and Resistors are 0603 Imperial size parts. I have all the ICs already in DIP/DIL, and I want them in sockets for easy replacement if required.

I had to make the footprints for the RCA Jacks, and the SVideo Jack. The RCA Jacks should have square holes on the front corners. I couldn’t see how to make such cutouts. I figure that I may just have to shave the plastic a bit on the RCA Jacks.

The board as well as the original prototype build can do a combination of outputs depending on your needs.

The board in the fully configured mode outputs RGBS, Red, Green, Blue and Sync (CSync or Combined Sync) with custom Audio and SCART Blanking voltage on the HD15 port. This is what you use for a SCART Input. With the Audio to the RCA Port and the SCART Blanking disabled (may or may not be an issue if it is enabled) the GBS Control also takes RGBS input. The GBS Control might get confused due to VSync being included too on the HD15 all the time. With the SCART Cable the VSync pin is just not wired to anything.

If it is set to HSync with the jumper then it outputs RGBHV: Red, Green, Blue, HSync, and VSync. VSync is always on the HD15 port. The GBS Control takes RGBHV, and that is the setup I use with it.

It will also do RGBS with an Inverted Sync with the other jumper. I think did that variation because of something to do with the GBS boards at the time. I don’t remember what it was about though for sure.

The other two jumpers are specific for doing the RGBS with SCART, that puts Red, Green, Blue, Sync, Audio and 5V on the 15 Pin output. It is how I used this adapter until I build a GBS Control to go with it. The GBS boards weren’t as good for this use until the GBS Control project came out.

When using the adapter in RGBHV mode the 74LS86 is not required. The 74LS86 is just used to make the CSync by combining the HSync and VSync. It is also used to do the Inverted CSync if that is enabled (which it would also Invert the HSync technically if it was enabled while the other jumper was in the HSync position). If you look at the schematic you will see it is just bypassed. The 74LS244 is a buffer to protect the Computer video output. The 74LS138 handles the CGA Brown Fix.

I have received the parts I had on order and checked all the footprints. There was an issue with the DB9 port footprint that I had to fix. I also had a few adjustments to make to the Mini Din 4 for the SVideo port. I made changes for footprint corrections and some adjustments to labeling then put in an order for the v1.2 PCBs. I am going to build one to replace the one I made in 2019 for my Commodore 128 RGBI, as I want SVideo. I plan to scrap the prototype, reusing the short DB9 cable and the short Commodore AV Din cable I made for it. I also plan to build up a second one for IBM CGA without the Commodore AV Port related components. If the board tests out, I will post the KiCad project files and Gerber files on Github. Once I have the boards built up, I intend to design a case that can be 3d printed.

Update: 3/4/23 v1.3 I am correcting the schematic, the original one had the 80 Column Monochrome Video from the Commodore 128 RGBI port going through the 74LS244, and it shouldn’t be. I am also adding R11 as an option for a “Resistive Ground (RG)” on the Shell/Shield of the 15pin output port, it probably should have a 100 Ohm resistor between ground to help prevent potential Ground Loop issues. To prevent ground loops with the cable shield is generally recommended to only be “grounded” on one end, so you can put in the optional R11 or omit it. All of the other connectors have their shield to GND/Ground.

Parts List:

0603 – Resistors
1) 150 https://www.digikey.com/en/products/detail/walsin-technology-corporation/WR06X1500FTL/13239274
1) 300 https://www.digikey.com/en/products/detail/yageo/RC0603JR-07300RL/726765
2) 470 https://www.digikey.com/en/products/detail/walsin-technology-corporation/WR06X4700FTL/13240646
1) 560 https://www.digikey.com/en/products/detail/yageo/RC0603JR-07560RL/726805
3) 680 https://www.digikey.com/en/products/detail/walsin-technology-corporation/WR06X6800FTL/13240808
1) 1k https://www.digikey.com/en/products/detail/walsin-technology-corporation/WR06X102-JTL/13241138
1) 2k https://www.digikey.com/en/products/detail/yageo/RC0603JR-072KL/726726

0603 – Capacitor
3) .1uF 100nF https://www.digikey.com/en/products/detail/samsung-electro-mechanics/CL10B104KB8NNWC/3887593

RCA Jacks
1) Black RCA Jack https://www.digikey.com/en/products/detail/kycon-inc/KLPX-0848A-2-B/9990118
1) Red RCA Jack https://www.digikey.com/en/products/detail/kycon-inc/klpx-0848a-2-r/9990119
1) Yellow https://www.digikey.com/en/products/detail/kycon-inc/klpx-0848a-2-y/10246556

Svideo Jack
1) 4Pin Mini Din https://www.digikey.com/en/products/detail/kycon-inc/KMDGX-4S-BS/9990073

1) DB9 Male https://www.digikey.com/en/products/detail/amphenol-cs-fci/LD09P13A4GX00LF/4997285
1) DB HD15 https://www.digikey.com/en/products/detail/edac-inc/634-015-263-032/806194

1) 74LS244 https://www.digikey.com/en/products/detail/texas-instruments/SN74LS244N/277299
1) 74LS138 https://www.digikey.com/en/products/detail/texas-instruments/SN74LS138N/277285
1) 74LS86 https://www.digikey.com/en/products/detail/texas-instruments/SN74LS86AN/277315

Optionally a surface mount barrel power jack. Various pin headers and a couple jumpers.

See the next part of this project. Building, testing and fixes below:

Commodore 128 80 Column RGBI/CGA to RGB Analog Adapter Part 3

Finished project: https://hobbytronics.home.blog/2023/03/12/commodore-128-rgbi-cga-to-analog-rgb-part-4-a-new-case/

Super Game Boy Console : Part 2 Revisions

I am going to add a few revisions for the Super Game Boy Console project here.

Super Game Boy Console

Joe realized the Left and Right Audio Channels were flipped, so that is a revision past the board I worked on and already posted. I opened up the SGB Console and swapped the Left and Right Audio Channels. Joe has updated the pcb designs on his Github project to reflect the change.

I quickly modeled a snug fitting plug to go into the hole that was for the 3.5mm jack of the Pi2/3. The first print was the same shape, but too lose, I made a size adjustment and reprinted it. The new one is very snug, I figure I will let it go and see if it gets loose over time. If so, I’ll put a bit of glue on it. It is resting there just above the pcb of the HDMI board so it has a little flat area on the bottom.

While I had it open, I also checked the fit of the new board for the back center screw post. It looks like I have it aligned and sized properly. That will mean that back screw post will not have to be cut out if the new board design is used. You still loose the front center screw, as the GameBoy Cartridge goes though that area. The level shifter ic in the area of that front center screw post is now “less” in the way, but it many need that post shaved down just a little still. Before the ic was resting on the edge of that post in the lower case, but now it should just be the pins and solder pads.

I looked at the Wii Controller port, I was looking if I could get a bit of plastic in to cover the front of the edge of the pcb at the top of the opening. This issue is because I used the Wii Breakout Board “with holes”. The 3d parts are designed for the smaller Wii breakout board Without Holes. You can try the Wii Breakout that doesn’t have the holes, it may fit better. I panelized the boards, so I got a huge amount of them, and for me the ones With Holes may be useful for another project at some point. There seemed to be two options to drop it all the way to the bottom of the opening, instead of raising it up from the bottom. Putting it all the way to the bottom didn’t work, it did give a bit of clearance on the top, but still not quite enough a gap in that tight area to reasonably get something to slip in from above. I then looked at raising it, the problem there is that the PCB and solder points on the back will be way to close to the upper main PCB. It may work in the short term that way, but overtime they may touch and short out. I thought of putting it so the pcb was turned downward. There just wouldn’t be any integrity in the 3d part, it would be way to thin I believe. The two posts that the top plate screws into could be removed to give clearance, or whatever is above the pcb may be possible to integrate into the top screw on piece instead. I’m concerned about how secure the jack would be mounted. I don’t think I will do anything else at this point about the mount. The way I did it, the jack is quite secure even if it has a 2mm gap above it. It is hard to see unless you get close and are directly in front of it. The Wireless Receiver for the controller also completely covers the area. I’d probably just suggest going with Joe’s smaller Wii breakout board, and use the models he provided unless you wanted to come up with a different mounting system of your own. I did use Joe’s lower mount plate model, and my jack fits right into that. For the Upper Screw on Plate, I am just using the upper most “flat” part of it, with the bits that would otherwise be hanging down cut away to fit properly. This presses the jack down tight by pressing down on the PCB side keeping it locked in very well.

I am finding it is slightly difficult to get the Gameboy Cartridge out. I am thinking if I had just left about 2mm more of the front case so the cartridge would be resting on it, that it would be a little easier to remove. The SGB cartridge slot is raised off the pcb by a few millimeters, and I have my opening closer to flush to the pcb. This angles the cartridge a little when I put pressure on to slide it out. I am just thinking if it had that bit of support on the end it may slide out slightly easier.

I also installed Joe’s updated firmware that uses the Home Button for the menu instead of Start + Select. On testing it I found an issue with the Color Scheme setting it would get stuck. Joe found and fixed that little bug and has released another firmware update on his Github page for the project.

https://github.com/joeostrander/consolized-game-boy

For myself, I believe I am going to call this project finished now. The minor thing with the small gap above the Wii port isn’t a huge thing even to ocd me. The 3.5jack hole was an issue I wanted to resolve though. I was going to also close the SD Card slot. I decided not to as the 3d mounting plate behind it does reasonably prevent someone sticking something in there and it is a bit of ventilation. I have played several games of Tetris on it and last night I got to the final Boss in Super Mario Land. It seems to work well, it is fun, provided the game itself doesn’t get frustrating. Thanks for reading and have fun.

Game Boy DMG Repairs and Upgrades

The only Vintage Game system or computer I have kept is my Game Boy DMG model. Based on the serial number I am guessing it was built in mid 1990. I had it from new and put a lot of hours on it playing games. It has seen better days. It was kept inside a case and never it an attic where it got hot. The case is pretty close to the original color, maybe some light yellowing. The display was missing lines, the glue failed on the screen cover and it fell off. I tried to glue the screen cover back on with super glue at some point, that held it on but ruined the “paint” on the under side of it.

The audio was being flakey on it at times. The screen even when it had the lines was well a DMG Screen.. I picked up some parts from Console 5 and somewhere else possibly on Ebay for my first pass of working on it.

So just as I said this was the “first pass” of parts that I purchased. Many of the items ended up not being in the Game Boy when I was finally finished. I broke the new Glass Screen cover, I did not use the replacement Volume pot, I did install most of the Cap Kit. The Button pads, were the wrong ones for the DMG. There also a back light kit with the Bivert board that I installed initially. Finally some Triwing drivers. It turns out my early Game Boy doesn’t have any Triwing Screws in it. It is all Philips screws. It isn’t in the picture, but as I had concerns about audio I did get a speaker as well, which I did not use.

It wasn’t too bad to clean up the old screen, you can see where the glue I had stuck it back on with years ago pulled the paint off the back of the plastic screen. I did have an issue with the new Glass Screen though.

Backlight and Bivert Mod:

So the first pass I went with the Backlight mod and the bivert board. The board was great. The removal of the old reflective layer was bad. Looking at the before picture, my screen wasn’t the best to start with.

Installing the board went very well following the provided instructions. There are 2 pins there to lift on the display connector on the CPU board side. The board is basically a carrier board for an inverter ic, the chip inverts the display. The light areas become dark and vice versa with it. With the Back Light rather than the reflective unlighted screen it makes it look better. The next part of the process was to take the reflective layer from the back of the LCD Screen. It was very tight, and while I got it off the lcd was missing more lines. I have seen people manage to repair the missing lines, but mine have been going bad since back when I was still using it in the 90s. Even so, it looked so much better with the backlight.

Yes it is missing more lines and even a couple horizontal lines now. Yes the Glass Screen broke installing it. The screen broke because it was very slightly oversized. I installed most of the capacitor kit, with the ones on the LCD, Power, and Audio boards. I tested the new ones and the old ones at the time on my component tester, none of them appeared to be bad. I left 5 of the 6 capacitors on the CPU board alone due to the other capacitors appearing to be fine, and due to being disappointed in the outcome of the screen, the glass cracking, and the fact that the audio issues didn’t clear up with the new capacitors.

Even in that condition the Game Boy was improved. I played it a bit like that. If the LCD wasn’t missing so many lines I would have kept it that way. It looked so much better and I wanted it keep it near original. That is why I didn’t go with one of the full LCD Replacements to start with.

On to a new LCD:

With the LCD not working properly though, I did end up getting one of the Replacement IPS LCD kits. The audio issue also ended up getting worse.

The instructions provided with the new LCD Kit worked out very well. This is an old project that I didn’t document much at the time. I did take a few before and after pictures. I would say the kits were fairly polished when I purchased mine, and they have been refined since.

The IPS Screen looks great, and has various color options to choose from. It doesn’t have the ghosting of the original lcd, which is a nice plus on fast moving games. The IPS Screen is the V2 or V3, which is now an older version of the screen, I am sure the V5s are nice these days. I put this in a few years ago now though.

Once the IPS Screen was installed the screen looked great minus the cracked glass cover. To fix that, I ordered another Glass cover, this one was also oversized, I filed it down with sandpaper on the edge to get it to fit. I also purchased a few more games for it to play with.

On to Sound Issues:

I was still having issues with the audio and it was getting worse. It would often not be working at power on, and then it may start working after a little while. With the audio getting worse I packed it up and let it sit in the case.

With Joes Super/Game Boy Console project catching my interest, I wanted to see if I could finally get my DMG back to full proper working order. Initially I thought maybe it was the audio jack. The Audio Jack has a switch built into it, when there are headphones plugged into the jack the internal speaker is disabled. I also wanted to look at the capacitors that were replaced and the ones that weren’t replaced. Looking at the Schematics for the CPU Board, the electrolytic caps are mostly audio related. Because I was working on the Super Game Boy Console, I let the DMG sitting in the case mostly. I wanted to add the Multiplayer Game Link function to the Super Game Boy Console, so I didn’t want to risk breaking the DMG before I could get that tested. I finished up the Super Game Boy Console recently (check my post about it if you are interested).

Last week after getting the SGB Console done and the Multiplayer tested I took a look at the DMG again. The audio is completely dead out of the speaker. I plugged in head phones and only had one channel of the audio and a lot of buzzing. I then took it apart, looking it over I didn’t see anything obviously wrong. The capacitors that were changed looked fine. I was able to tell that the CPU Board had 5 original capacitors still on it, as only one was replaced on it. The Audio Jack which was still a question for me has a lot of oxidation on all the exposed metal on it. I have seen other connectors do this at times. This socket has a switch in it that disables the audio. I had previously tried to clean it with contact cleaner but nothing changed.

Today I went to look at it further. I replaced the 5 remaining capacitors on the cpu board. I did test the capacitors I removed and the new ones before installation. With the tester I have for them, the old ones appeared to be fine. I did put quite a few hours on the Game Boy back in the 90s, but likely no where near used them for their rated hours at the temperatures the Game Boy runs at. I probably wouldn’t go to the trouble to replace the Capacitors on a DMG again anytime soon. Certain hardware from the later 90s has bad capacitors in them due to defective design or bad mix in the electrolyte etc. I also feel capacitors from the early 80s especially in equipment that gets quite warm, will have a greater chance of being in need of replacement. In some of my retro computers and other devices I have found capacitors that even my limited tester indicates are out of specification.

I looked over the boards again, but didn’t find any visible problems. I did clean up and redo some solder points, redid the power switch, the Link Port and some other solder points incase they had been stressed although I had not seen any visible cracked solder around any of the pins. I cleaned the tarnish off the exposed metal parts of the audio jack. I then removed the audio jack from the pcb with my desoldering gun. It shouldn’t have been awful to get off with the solder sucker. I tested it, and none of the pins were connected once it was pulled out. Checking the schematic, and tracing the wires I found that pin 6 of the audio amp is to be switched to ground, and that is the pin of the audio jack that goes to the white wire on the audio board. Testing again on the jack there was no continuity to the other half of the built in switch. I plugged in a 3.5 plug and it didn’t connect the switch. I was just able to see where the switch moved when the jack was inserted. I sprayed it with contact cleaner and used an Xacto blade to get a little under the switch. I was able to get the contact working again spraying it again and using the 3.5 plug in and out a number of times. I tested and had under 2 Ohms then. I also tested the 3 connections on the 3.5 plug and all are making good contact now. I then soldered the jack back onto the pcb and retested the switch and 3.5 plug contacts again.

I have some other pictures of the boards before cleaning off the flux and reinstalling them. While I had them out, I put contact cleaner in the Multiplayer Link Port, the Volume pot, Power Jack and Power Switch.

The internal speaker worked properly again after reassembling the DMG. There is a bit of hum, but that is mostly from the AC Adapter, when on batteries there is nearly no hum. I don’t remember the hum being there in the 90s when using the same AC Adapter. In looking into the hum, it was reported that the IPS LCD kit adds some Hum to the audio, due to higher current draw, well that is what they said. Maybe it also is making some of it due to interference from it’s operation being picked up in the audio amp or something. It is not very bad, but certainly is more present when on the AC Adapter. It was worse actually before cleaning the power port, power switch and other contacts, I thought it was from the Audio Amp itself, but it was that same hum just worse before working on it this last time.

Reassembled and Testing:

The Directional Pad didn’t work properly though. While I had it apart, I had switched out the contact silicone pads, the Start, Select, A and B buttons all worked properly with the new pads. I took the DMG apart again and checked the pads. I cleaned the contacts on the PCB. I then tested conductivity of the new Directional Pad and also the Original Pad. The Original Pad was more conductive. I cleaned it lightly with IPA and reinstalled it. I also looked at them, and the new pad is designed just a bit differently. I tested the DMG again and the directional pad was working properly. I had swapped them as they are old and they look worn. It also seemed the directional pad wasn’t always working as well as I liked. It seems fine for after cleaning, hopefully it holds up.

The volume control is good and smooth, it isn’t scratchy at all. The power switch works properly making good contact, and the power jack is giving good connection too. The power cord could give some crackling before as it swiveled in the port on occasion before. It seems everything is finally working properly again. I’ll get a chance to play the old DMG again.

Looking at the photos from when I started working on the DMG, it has been over three years since I put in the Back Light mod and started putting the capacitors into it. It is nice having it finally sorted out and in good working condition again.

Trying a little Multiplayer Gaming:

Now I can pair it up with my Super Game Boy Console and play some two player Game Boy games.

Super Game Boy Console

You can check the post about the Super Game Boy Here.

Super Game Boy Console

I was watching the Andy West’s video of Joe Ostrander’s Game Boy Console project on the Element 14 Youtube channel. It was inspired by and earlier project video that Andy West had done awhile ago. In the new video Andy builds one of Joe’s v3.0 boards, and gives some details I will likely be missing here.

The latest version from Joe was v3.1 it uses a Raspberry Pi Pico, a Super Game Boy Cartridge with a few other parts to build a Super Game Boy Console in a tiny Retroflag NESPi case. With v3.1 Joe used the Super Game Boy Cartridge Port instead of the SMD Cartridge Port Andy had for the v3.0.

Here is the Video:

I liked this project because it included some things I could practice with and some new things.

Andy’s original project included the DMG Link Port for Multiplayer games, but Joes project did not. I looked over the schematics for the SGB and the DMG as well as Joe’s version and it seemed simple to add that feature.

The Super Game Boy can play the original Game Boy DMG games. The Super Game Boy didn’t have the Game Link Port, but the CPU was the same except it doesn’t have the Nintendo name scrolling down the screen at power on (unless the cartridge isn’t recognized properly you never see that screen at all).

I was able to contact Joe and he sent me a copy of the Easy EDA Project files. He had it listed at v3.1 at the time with the Super Game Boy Cartridge port. I modified Joe’s main pcb to add in the parts required for the Link port. This was the first time I have worked with Easy EDA. It took me a little bit to get used to working with it. I have used Eagle in the past for other projects, but for Hobby work it is very limited in board size. Easy EDA can send an order to JLCPCB for production, or your can have it generate Gerber files to send to your favorite PCB Producer. I made a Footprint for the DMG Link Port is a recreation of Gekkio’s KiCad DMG Link Port KiCad footprint in Easy EDA, so that I could make the DMG Link Port adapter board.

https://github.com/Gekkio/gb-hardware

There is a single Pi Pico that handles controller input and generates the VGA Video output. It also uses a VGA to HDMI Adapter to take the VGA output from the Pico to HDMI including the Audio.

It has options to either use a NES Controller port and Controller, or to take a Wii jack and use a compatible controller for that, be it one of the Wii Classic type controllers or one intended for the NES Mini such as I have used. There is different firmware for the Pico depending on which controller type you go with. Joe has both versions ready to go for you in the .u2f format. I went with the Wii port, and the cheapest way for me to get it quickly was to buy a Wii controller extension cable and salvage it out of there. I figured it was likely I could salvage and reuse it, and while 3 of the pins were cut short, it did turn out to be the regular through hole port and works just fine in my case. There are different Controller Port Mounts and as I said Firmware depending on which controller option you go with. The firmware is in the .uf2 format that is very easy to install to the Pico. You first download the .uf2 that you need on your computer, then get a usb cable for the Pico, hold the button on the Pico as you plug it into the USB port on your computer. You can release the button then, if you did it right, the Pico will show up as a drive on your computer. From there copy and paste the proper .uf2 file into that drive. The Pico will upload the code and reboot itself automatically. The files are gb_vga__pcbv3_nes_controller.uf2 for the NES Controller Port and gb_vga__pcbv3__nes_classic_or_wii.uf2 for the Wii Controller port (filenames prior to 1/15/23).

Update: 1/15/23 It appears Joe released an update for the code on the Pico, the new version only supports the Wii type controller. The Home button now brings up the OSD Controls. I’ll have to check it out later.

The Controller Ports also require different Adapter PCBs and wiring as well depending which you go with. The PCBs are labeled on both the Main PCB and the Breakout Boards. The pictures of my prototype board are not the final design for v3.21 on the final one (which I show a render picture of at the end of this post) you will find the “<– NES” and the “<– Wii” markings on the silk screen. Be sure to use 3V3 for the Wii Breakout. I have updated Joe’s Wii Breakout board to list 3V3 instead of VCC. For the NES use 5V and Gnd just as the board is labeled to accept.

There are numerous parts. Much of it is surface mount, minus the Pico and the reused SGB Cartridge port.

BOM:

Name	Designator	Footprint	Quantity	Manufacturer Part	Manufacturer	Link
27pF	C1,C2	0603 CAPACITOR	2	C1608C0G1H270J080AA	TDK Corporation	https://www.digikey.com/en/products/detail/tdk-corporation/C1608C0G1H270J080AA/513761
1uF Tantalum Polarized Capacitor	C3,C4	1411 CAP-SMD_L3.5-W2.8-R-RD	2	T491B105K050AT	KEMET	https://www.digikey.com/en/products/detail/kemet/T491B105K050AT/3724722
100pF	C5,C6,C7,C8	0603 CAPACITOR	4	06035A101JAT2A	KYOCERA AVX	https://www.digikey.com/en/products/detail/kyocera-avx/06035A101JAT2A/563285
MMBD7000HS-7-F	D1,D2,D3,D4,D5	SOT-23-3_L2.9-W1.3-P1.90-LS2.4-BR	5	MMBD7000HS-7-F	Diodes Incorporated	https://www.digikey.com/en/products/detail/diodes-incorporated/MMBD7000HS-7-F/2179586
1M	R1	RESISTOR_R0603	1	WR06X105 JTL	Walsin Technology Corporation	https://www.digikey.com/en/products/detail/walsin-technology-corporation/WR06X105-JTL/13239221
10K	R2,R3	RESISTOR_R0603	2	RNCP0603FTD10K0	Stackpole Electronics Inc	https://www.digikey.com/en/products/detail/stackpole-electronics-inc/RNCP0603FTD10K0/2240139
1K	R4,R6,R8	RESISTOR_R0603	3	RMCF0603FG1K00	Stackpole Electronics Inc	https://www.digikey.com/en/products/detail/stackpole-electronics-inc/RMCF0603FG1K00/1713699
500R	R5,R7,R9	RESISTOR_R0603	3	RT0603BRC07500RL	YAGEO	https://www.digikey.com/en/products/detail/yageo/RT0603BRC07500RL/7708292
47R	R10,R11	RESISTOR_R0603	2	RC0603JR-0747RL	YAGEO	https://www.digikey.com/en/products/detail/yageo/RC0603JR-0747RL/726793
180K	R12	RESISTOR_R0603	1	RC0603JR-07180KL	YAGEO	https://www.digikey.com/en/products/detail/yageo/RC0603JR-07180KL/726723
510R	R13,R14	RESISTOR_R0603	2	RC0603JR-07510RL	YAGEO	https://www.digikey.com/en/products/detail/yageo/RC0603JR-07510RL/726801
220R	R15,R16,R17,R18,R19(Power/Reset Board)	RESISTOR_R0603	5	RMCF0603FT220R	Stackpole Electronics Inc	https://www.digikey.com/en/products/detail/stackpole-electronics-inc/RMCF0603FT220R/1760809
ABLS-4.194304MHZ-D-4-Y-T	X2	CRYSTAL-SMD_L11.4-W4.7-LS12.7	1	ABLS-4.194304MHZ-D-4-Y-T	ABRACON	https://www.digikey.com/en/products/detail/abracon-llc/ABLS-4-194304MHZ-D-4-Y-T/9997833
SN74LVC245ANSR	U4	SOIC-20_L13.3-W5.5-P1.27-LS7.8-BL	1	SN74LVC245ANSR	TI	https://www.digikey.com/en/products/detail/texas-instruments/SN74LVC245ANSR/499514
Raspberry Pi Pico	U5	RASPBERRY-PI-PICO	1	SC0915	Raspberry Pi	https://www.digikey.com/en/products/detail/raspberry-pi/SC0915/13624793
Super Gameboy Cartridge Header	U6	SUPER GAMEBOY CARTRIDGE HEADER	1		Nintendo	From Super Game Boy
DMG-CPU	U1	DMG-CPU-B	1		Nintendo	From Super Game Boy
LH5264 RAM	U2,U3	DMG LH5264	2		Nintendo	From Super Game Boy
GANA VGA to HDMI Audio Video Converter			1			https://a.co/d/2GTq5d7
Retroflag NESPi Case Plus			1			https://a.co/d/1K0sy7a
Super Gameboy Cartridge (to source the CPU, RAM and Cartridge Port)			1		Nintendo	Search Ebay
Wii/NES Classic Port 90 degree (Optional this or the Original NES Port)			1			https://www.aliexpress.us/item/3256804436132647.html
Original NES Controller Port (Optional this or the Wii Port)			1
Pin strip / header (for the Pico if it didn’t come with them)			1
Wire 24awg Silicone Insulated Wire						https://www.amazon.com/gp/product/B07TJXRGXM/?th=1
Wire 30awg Insulated Wire						https://www.amazon.com/Treedix-Copper-Wrapping-Jumper-Optional/dp/B08D6D1TKH/

Super Game Boy Console Main Board PCB	sgb_cart_motherboard_v3_21
Power and Reset Board PCB	power_reset_v3_21
Wii Controller Breakout Board PCB (Optional this or the NES Breakout)	wii_jack_w_holes_v3_21
NES Controller Breakout Board PCB (Optional)	nes_breakout_v3
DMG Game Link Multiplayer Breakout PCB (Optional)	dmg_link_v3_21
USB Power with Data PCB (Optional, to Program the Pico in the case)	pcb_v3_usb_w_data

BOM

I used the USB Port from Retroflag instead of the optional “USB Power with Data PCB”, I don’t expect to need to reprogram the Pico that often. I ordered in Joe’s Wii controller PCB. I also ordered his Power and Reset button board. I ordered the version of the Main PCB that I had added in the Link Port parts. For the Link port I ordered in a DMG-07 Four Player adapter to salvage off one of the Link Ports as Joe suggested.

I have since created a somewhat more refined version of the Main PCB and some other PCB changes. Keep in mind the BOM list above is for the v3.21 board not the prototype I have pictures of here. Some component designations have changed and D1 is now a Diode Array on the “finished” board. I also created the DMG Link breakout board. I used the protoboard version as seen in the pictures, but the Mount for the DMG Link board is designed for the PCB.

The first part was to do the main PCB modifications. I ordered the required boards, I also found out you can have them panelize the boards for you. I now have a crazy number of Wii Controller Breakout boards for the same price I would have paid for 5. That opens up some real possibilities for when I have a small board I would like more of.

The next part of the project was sourcing all of the other parts. Joe’s BOM at the time had a mistake on it the 22pf capacitor listed was a 0201 imperial part. The BOM above is listing a 0603 imperial sized part. That is an easy mistake to make as 0201 imperial is 0603 metric.. The parts listed above are the specific part numbers I ordered except for the wire. If you don’t care to do the Link Port, then you don’t need R15-R18, D1-D5, or C5-C8, or the DMG Link PCB, and the Link Port itself.

Once I had all the required parts it was time to prep the various parts. For the Retroflag case, I had to desolder the USB power board from the Power Reset button board so I could reuse it. I then had to desolder the Power and Reset Buttons as well as the LED and the LED Light pipe so I could reuse them. I then installed the Power and Reset Buttons and attached the USB power board to the new PCB. Just a note I missed seeing the pad for the Resistor for the LED on the board, I revised the board so that was listed on the silk screen and installed a 510 Ohm resistor on it ( I expect a 1k resistor would do well too, if you don’t want it so bright).

The case requires a bit of modification to fit the new parts. The opening where the two USB ports needs enlarged depending on which Controller port type you go with. The top needs modified by cutting out the opening for the Cartridge to get in. That requires taking the front center post out of the top as well. Be careful to not remove too much. I did have to slightly trim some of the top posts (but not all) about the thickness of the PCB to get it to fit nicely. The back center post was removed on mine as well using the PCB as it was on the prototype. I revised the PCB so that v3.21 should let that back center post remain now. To see how much the top posts needed shaved down (about the thickness of the PCB) just check the fit of the PCB laying in the top of the case, it basically needs to sit level and about flush with it. For the Pi Pico to clear the top, I had to remove the tabs and a little bit more where the fan is to snap in. I think if the Pico is mounted with short posts it would have more clearance. I decided to mount it with some header sockets so I can remove it if I want/need to in the future. For the bottom there there is some material that needs removed from under where the green mounting part goes in for the Controller port. That part is where the Controller Port is mounted as well as the hole in it is the one hole that holds the VGA to HDMI board in place. Below you can see the modifications to the case. I didn’t think to take “before pictures”. You can also see the new Power Reset board, USB Power board as well as the Wii board mounted into the bottom of the case. The Link Port will be added to the lower right cavity later.

Beyond the case prep, and pulling those parts from the original Power Reset board there is the Super Game Boy Cartridge parts to deal with.

With the Super Game Boy, we pull the board. We need to salvage four parts. The CPU, the two Ram Chips (they are identical) and the Cartridge Port. Below you can see the board after those parts are removed. I did clean the flux from the board and kept it if I find a future use for it. To remove the chips I used the technique that Andy West showed with Low Temp Solder alloy. I watched him do it a couple times, I then watched some other people using it to remove chips. For me I wasn’t having all that great a luck with the CPU, so to make the process go easier I used my hot air station to make it easier that helped me a lot. It seemed that in Andy’s video it must have also taken him awhile to get the CPU off, I felt better using the hot air as the heat was applied for less time than it was taking with the iron alone. I am sure I would have gotten it with just the iron, but it is also nice to use the hot air station for more than heat shrink now and then. That low temp alloy is weird stuff, the flux smells odd too. It is the first I used it. Be sure to clean the low temp solder from the chips with some solder wick after removing them. It needs removed as it is not good to have it on the final board it doesn’t work as well as solder.

For the Cartridge Port, I used some money from Christmas to purchase one of the cheaper desoldering guns. I also used the new desoldering gun to remove the switches from the Power Reset board and VGA and Audio sockets from the VGA to HDMI adapter. I could have done it with my desoldering iron, it is shown in one of my C64 refurbishing posts. I also used it to pull the Link Port from the DMG-07 4 Player adapter.

Super Game Boy after removing the required ICs and Socket to be reused.

Below is the VGA to HDMI Adapter after it was prepped for installation. The VGA Port and the 3.5mm Audio port had to be removed. Even with the desoldering gun, I ended up pulling some of the through holes out of the VGA port, nothing that was a problem though in this case. It has 5V (Large Red), Ground (Large Green) for power that go over to the Power Reset board. Then the Dark Blue (Left Channel) and Brown (Right Channel) wires go to the pad for Left and Right audio over on the Main PCB, Ground is all joined so that doesn’t need a wire in this case. Then we have the Red, Green and Blue for the R, G, B pins then the Orange ( V Sync) and Yellow ( H Sync) and I did wire the Black wire for Ground there. The small wires are 30awg Wrapping Wire.

Below is the main work done on the unit. This was before adding in the Link Port.

Above you should be able to make out most if, not all the wiring there. I did put 2.5m screws into the Link Port holes to give it stability. You can possibly make out the green 3d printed washers under the screw heads. I didn’t want to scratch the pcb, and there is one trace right there by the left screw. The revised board has that trace relocated now away from the hole.

There is not too much going on on the top side of the PCB. The picture above was before I added the screws to secure the cartridge port. It is just the port and the Pico. I am using header sockets and pins so the Pico is removable if needed, but that shouldn’t be a big deal to solder it in with the normal pin headers. If you go to put it on header sockets, you may want to test fit it in the case to make sure it will fit. For me it got pretty close to having to cut out all that area where the fan is intended to be mounted.

To add the link port I modeled a part to sit down in the remaining cavity in the bottom corner of the case. I put the 3d printed link port mounting plate in for a test fit and I could not get it back out. Luckily my chip puller was able to get in under it and pop it out without damaging the case. The part is made so that you put the Game Link port in place and then press the 3d printed part in place, it clamps the port in by the little ears sticking back on it a bit. The main thing is to get the opening made in the right place at the right size for the port. I made a template of the port shape, then drilled a hole where it would be inside the area to help me get an idea on placement and got lucky enough I had it right in the end. I used a combination of small drill bits and an Xacto Knife.

I used two of the remaining shorter smaller diameter black screws from Retroflag to screw down the port PCB (or protoboard in my case). I didn’t expect the green printed part to fit in so securely, if it works loose I can just add a dab of glue and it shouldn’t be able to move. I do have all 4 sides fairly snug and the Link Port is put out into the case plastic so it can’t lift out on that side. I used Design Spark Mechanical to make that adapter mount, it was quite easy, far easier than getting something that dimension specific done in Tinker Cad. I have to spend more time using it. I probably could have made the Ampi case in it far more easily if I had stuck with it.

The image above is a view of the DMG Link Port Mount model. The first test print worked perfectly, which is uncommon. It was a snug press fit, the port fit right into the cavity for it, the screw posts printed solidly and the holes in it are the right size for the screws. You have to put the Link PCB with the jack on it while the mount plate it loose yet, just work them in together and you should have a good fit for both. It may look like the screw posts are back a bit far, but that is because my piece of proto board is a little shorter than the PCB I designed. I made the mount to match the PCB design, not the piece of proto board I am using.

Above is are renders of the DMG Link Port Breakout Board.

The unit is complete now and tested. I used it awhile without the Link Port as I was still sorting out some things on how I wanted to install it. I also had tested the Link function and it wasn’t working due to me not knowing that there is a twist in the cable, so two of the pins had needed switched with how I was connecting it up.

I have the revised v3.21 board shown above as it is now. Like I mentioned some component designations have been changed. D2 R18 etc. I have relocated some pads. I put the Wii pads together by bringing down the 3V3. The Work Ram is lower on the new revision. I think it may now clear the center front post in the lower case body, but with it where it is on my prototype it just gets in the way a little bit. I have added a notch in the board that should allow keeping the back center hole in the case instead of cutting the post off.

Joe has pulled my Fork into his project and corrected the Left/Right Audio being flipped as of 1/20/23.

https://github.com/joeostrander/consolized-game-boy

If I do more updates they will be available in my Fork of Joe’s project and hopefully get pulled into his:

https://github.com/Markeno76/consolized-game-boy

There are a few things I may do yet. Time will tell. I’ll have to fix the schematic listed here for the Left/Right being flipped.

Full Schematics:

Follow up post :

Super Game Boy Console : Part 2 Revisions

AMPi4 – Custom Amiga Inspired Pi4 Case with Mechanical Keyboard

3d Files are here: https://github.com/Markeno76/AMPi4

Some may ask why make a Wedge case with Mechanical Keyboard with Full Size Ports for the Pi4b when there is the Pi400. I do like the Pi400 it certainly has it’s place. The AMPi4 was made for a bit different use case. I wanted a complete case with a mechanical keyboard, robust full size ports, a bit of weight to it, as well as SSD/NVME for storage and the OS.

If you look at my other posts here, you will see I like working with many of the 80s era computers. I never had an Amiga, and they are quite expensive these days. I also don’t want to dedicate more space for the storage of Retro Computers. I found after I started to get more and more Retro Computers around, that I am less and less likely to go to the effort of connecting one up and using it.

First I looked at the Pi400, which I thought may be a good option for Amiga emulation, and possibly more of the retro computers. The keyboard didn’t feel right, it was to small and too light so it easily to slides around the desk. The power adapter and other connectors are easy to accidentally pull out playing games etc. I also don’t like SD Cards for the OS as I have lost a few over the years in Pis. In many cases a Pi SD Card can quickly and easily be recreated or restore from a backup copy. For this setup, it takes a bit of work to get the OS just right, also it is to be a Living OS. I want to use it for Retro Computer Emulation, but I also want to use it for Linux with the GUI as a more modern option for basic usage and possibly some development work for various Microcontrollers and such.

I did also try Amiga Forever on my Windows pc, but it just doesn’t feel right on a wide screen LCD and Tower pc.

There are a number of Keyboard Wedge cases people have created for emulation systems. There are some for the Mister, which also I believe had a Pi option. I had seen some cases that take the Pi400 and wrap it into a larger case. I just did not find a case that was exactly what I was looking for. They were generally missing something I wanted in the system. They generally were a bit complex in design, with many parts and well they did have some style to them.

I expected I could come up with something that had all the features I wanted and be simple to print and build. It is a rather basic design. Mostly made to be easy to print, but certainly I am not that creative or very experienced in 3d modeling.

With that I looked at what I want in this setup:
1. Amiga Wedge inspired case. The initial case looked more like the Ti99/4a in profile until I narrowed the electronics compartment at the back.

2. Mechanical Keyboard

3. Full size HDMI Ports

4. Ethernet Port

5. USB Ports accessible, and more of them.

6. SATA SSD or NVME Drive

7. Internal Power Supply. This adds to it being simple to connect and adds weight to the system.

8. DE9 Ports for Joysticks (This doesn’t work quite right, I may yet get that sorted.. For now I have let that alone.)

Below is a view of the Second Revision of the case design that I printed. Some photos may be of the First Revision. There is a newer revision of the case with mostly small modification to adjust for some “mostly workable” but inconvenient items. I do plan to print that newest version of the case at some point. This part of the case is 300mm wide, so not every printer can print it. My S8 printer is 310×310, it seems that it is not possible to get the full 310mm though I got about 307mm with a correction to the alignment. That alignment issue had caused a mess with the First Revision print on the left side as it was trying to push the bed further than it actually could be moved.

Looking at the back panel, the far left hole is for the momentary Safe Shutdown Button that I put standard on just about any Pi project. It is the same type of setup as my Bartop Arcade machine. Next is the IEC AC Power port. After that is the Fuse. There is No Power Switch, I kind of would like one, but it was getting crowded. Then the 2 full size HDMI ports with the 30mm Fan beside them. RCA ports for the Composite Video and Audio output. Then a place for a standard Keystone jack, which I installed a RJ45 jack into for ethernet. Then a single USB Port. The far right side there just the place for the DE9 Joystick ports and the USB3 Hub ports and mounting posts for the screws. The Pi4 standoff screw points there in the middle of the case and holes for mounting the Meanwell 5Volt power supply.

To design the case I had to work out the parts I was going to use inside. I needed to make it big enough and get placement for all the parts. I created placeholders by measuring various components and making simple placeholders for them. Yes it would have been better to build the case in something other than Tinkercad. I would rather use something else, but that is all I had enough experience with at the time. The Keyboard Tray was started in Designspark Mechanical. I found I just wasn’t familiar enough with it, and it was slowing me down making it likely I would give up before finishing the project. I then went over to Tinkercad to design most of the case.

I already had two of the type of keyboard I chose, so I knew the how it was built. I was thinking initially to only design the electronics enclosure and attach the whole keyboard to the top of it. I decided to recreate the keyboard case “tray” instead. The keyboard tray/case is tapered a bit, making it problematic, the “feet” and “cord” openings were not optimal either.

Below is the original tray and my test print of the recreated tray. The Keyboard tray is two parts as it is well over 300mm wide maximum my largest printer can print. You can see I am at that point using the black keyboard instead of the white one. They are physically identical, just different plastic and paint colors.

My first print print of the keyboard tray showed me the post positions were off and unusable. I adjusted for that and ended up with something closer. Even at being closer, the far left two posts are too far left by a little bit. Two others there are more slightly off. The smaller right side part was just about perfect for all posts, it was a second print as well. The posts were positioned based off of measurements, which wasn’t the easiest to get perfect. I think I did measure starting at the right side, so any variance was likely to get worse going further to the left side of the keyboard. I have since revised the position of those posts.

There is an issue in that the holes are to small and the posts tend to sheer off at the base. I carefully drilled the screw holes a bit larger after printing. I would revise the hole side on the 3d model, except it is in Tinkercad, and that’s really not practical in Tinkercad. That is why I wanted to use something else to make these models. If I had worked out using DesignSpark Mechanical or some other 3d design package it would have been an option to resize thoses holes after the fact. There is also variation in 3d printers, so you may find hole sizes are a bit different anyway, but likely not going to be large enough When it is together it is very solid. Not all of the posts are screw posts, some are just supports that don’t need holes at all.

The keyboard is mounted with brass inserts. These inserts are actually in the Top not bottom, but the screws come up from the bottom. They are very unlikely to ever pull out as they are pulled in tighter by the screws from the other side. Those are the four in the top of the keyboard that rest on those posts/pillars. The inserts in the keyboard tray here are actually salvaged out of old broken laptop cases. The 4 here in the upper area where the posts are did take longer screws I believe. I have a selection of Metric m2.5 screws of different length. There are also 4 more along the bottom edge of the keyboard as can be seen as holes without the inserts in them in the first keyboard photo. Those four lower ones are short screws.

Above is the original black keyboard when it was being installed.

Above you can see the various internal components test fit into the chassis. The USB Cable was modified already. The first revision the DE9 ports didn’t fit, the fan had an integrated grill that printed awfully and blocked to much of the fan.

Above most of the internal wiring is completed. The DE9 Joysticks ports are not yet wired to the GPIO and the Fan isn’t wired in yet. It is quite tight in there. The wires on the GPIO are going to the two LEDs on the top cover. Power and Activity lights.

Above is the second test print of the corner of the case as the DE9 ports didn’t fit and the USB Hub wasn’t properly positioned. The little black cable is the cable I made up for connecting the USB Hub. Due to the limited space those cables are made up with usb connectors without the shell covering them. The bottom cable there is the short keyboard usb cable, it plugs into the bottom of the keyboard where that square opening is in the keyboard tray.

The 5V case fan is powered that little buck converter there between the power supply and HDMI port. The fan was louder than I liked, so I used the buck converter to lower the voltage a bit to make it quieter. You can see the 2.5″ SSD Drive is in the case. It also still has the 2gb Pi4 in it in this picture.

The DE9 Joystick ports were very problematic. The first option for using them didn’t work at all, well it made my Power and Activity LEDs not work. The other options I tired required rewiring them to other GPIO pins. They were unreliable. It would have incorrect button presses as the timing must have been off for some reason. I was initially only going with Atari 2600 or the Commodore 64 3 button hybrid, but when those didn’t work I went with another option that was to have supported the Sega Genesis 6 Button controllers. I am not sure if the issues can be sorted. I have went to building and using a USB DaemonBite Retro Controller adapter setup for the Sega Genesis 6 button controllers. It even seemed to have faulty timing issues with the Genesis Controllers. I found a fix for that which seems to be working properly now. The DeamonBite adapter can be seen in the picture below. It is the more or less triangle shaped blue box to the right side with two DE9 ports on it. It is actually a simple build with an Arduino board controlling it. The case was available on Thingiverse. I want to go back to get those DE9 ports working off the GPIO. I have thought of putting an internally connected DeamonBite controller and wiring it to the case’s ports. That would loose me my USB2 port in the back though.

The system runs Raspbian and Retropie. I have it setup to boot into Retropie, but I can exit that and go into the GUI and use Raspbian. The main intention of this system is to run Retro Computer games. I worked to set it up primarily for Commodore 64, Atari 8bit, Ti 99/4a and Amiga emulation.

It was setup with at 2.5″ SSD Drive, and I ended up switching to an NVME drive later on. The keyboard was the cheapest version of the Redragon K552 87 key keyboard which was the Black version with Red Switches. I don’t like Red Switches. Once I was confident that the project was going to work out, I purchased the more expensive White version with the Brown Switches that I prefer.

The newest Revision 3 main case has various changes. Mostly small alignment changes. The Pi is moved to the left because the 3.5mm jack couldn’t fit with the outer plastic cover on it. I may not have moved it enough, I am not sure as the space is very limited and I have not reprinted it yet. Some other small adjustments to the back ports. I also changed the “vents” below the keyboard in the main frame as with the current shape they didn’t print very well.

I later found out that the key switches on the keyboard are removable. They aren’t quite “standard”, the contact pins on the bottom are smaller than standard switches. They probably won’t make contact in another keyboard. Standard switches won’t fit into the keyboard without filing the contacts down to be narrower like the ones that come in it. It is possible to do, I replaced several of the switches in my son’s keyboard as W A S D etc were worn and not working well. I will see if the Key Switches that Adafruit sells hold up better than the factory switches did.

STL 3D Model Files are here:

https://github.com/Markeno76/AMPi4

Main Parts List:

MEAN WELL 323282 RS-25-5 AC to DC Power Supply, Single Output, 5V, 5 Amp, 25W, 1.5″ : AmazonSmile: MEAN WELL 323282 RS-25-5 AC to DC Power Supply, Single Output, 5V, 5 Amp, 25W, 1.5″ : Electronics
Redragon K552 Mechanical Gaming Keyboard RGB LED Rainbow Backlit Wired Keyboard: https://smile.amazon.com/gp/product/B016MAK38U/
USB Hub 3.0 – Rekidm 4 Port Aluminum Desk USB Hub 3.0 Clamp Design: AmazonSmile: USB Hub 3.0 – Rekidm 4 Port Aluminum Desk USB Hub 3.0 Clamp Design for Desktop, Computer, PC, Table Edge with Durable Adjustable Clip, Space-Saving Mountable USB Hub Fast Speed Transfer : Electronics
HDMI Coupler 4K*2K HDMI Extender Female to Female HDMI Adapter Connector Coupler with Panel Mount Holes: AmazonSmile: HDMI Coupler 4K*2K HDMI Extender Female to Female HDMI Adapter Connector Coupler with Panel Mount Holes HDMI Jioner Kit (5 Packs) : Electronics
Micro HDMI to HDMI Cable, Ultra Thin HDMI Cable 35cm/1.15Ft, Super Flexible Slim: AmazonSmile: SMALLRIG Micro HDMI to HDMI Cable, Ultra Thin HDMI Cable 35cm/1.15Ft, Super Flexible Slim High Speed 4K 60Hz HDR HDMI 2.0, Compatible with GoPro Hero 7/6 / 5, for Sony A6600 / A6400-3042 : Electronics
IEC 320 C14 Panel Mount Plug Adapter Power Connector Socket: AmazonSmile: 10 Pack AC 250V 10A IEC 320 C14 Panel Mount Plug Adapter Power Connector Socket Black Screw Mount 3 Pins Inlet Power Plug Socket by MXR : Electronics
Fuse Holder 250 VAC 10 A 125 VAC 15A: BOJACK 10 Values 30 Pcs 5X20mm Black Screw Cap Fuse Holder 250 VAC 10 A 125 VAC 15 A with 10A/15A Fast Blow Glass Fuse kit – – AmazonSmile
30mm 5V Fan (The optional buck converter was used to lower the 5V to make the fan quieter)
16MM Momentary Push Button
Pi4b
USB 3 to NVME (or USB 3 to SATA adapter depending on the drive used)
NVME (or 2.5″ SATA SSD Drive)
2 DE9 Male Adapters
Dupont 2.54mm cables or connectors and wire.
2x3mm LEDs (and 220ohm Resistor)
RCA Jacks
RJ45 Keystone Network jack
USB A Single Panel Mount Port
USB A Male solder connectors: Amazon.com: Maxmoral 10PCS USB 2.0 Connector A Type Male 4-Pin Plug with Black Plastic Cover DIY Connector : Electronics
Provided the prints are successful, the 4 printed parts take most of a 1kg spool of 3d printer filament.

There were various other supplies, M3 Brass Inserts for the top cover, some M2.5 Brass Inserts for the keyboard mounting. Various M3 and M2.5 screws of different lengths.

Lenovo Tiny PC Mount

I have a Lenovo Tiny PC M600 Series that I wasn’t sure what to do with. It is a Pentium based CPU so not the best to use for very much. I have my Desktop PC on the other side of the room behind me when I am at my electronics bench. I’ve been wanting to put something over on the bench for awhile. I had various thoughts of using a Pi4 or something, but they are at such a premium right now I feel very doubtful I’ll get my hands on another one. They are not worth what they are currently selling for, if the Pentium Tiny doesn’t work out, I could buy an i5 Tiny for the same as the Pi4 these days.

Lenovo has made VESA Mount adapters for the Tiny, but I decided to check for a 3d printed mount design. I found a couple, but most were not what I was looking for. I picked one out that was close, but after taking measurements for some reason it was too narrow. All Lenovo Tiny’s I have had over the years have had the same dimensions.. So I find that odd.

I started over and came up with a one piece design that I liked, but it was a big waste of support material. I then came up with a two part design to save material and not need any supports. The first test print warped rather badly due to part of it coming loose from the bed part way through. It was good enough to test my dimensions, which needed some minor adjustments. I made a few other changes and printed it again, this time it stayed to the bed properly. The Tiny also fit it perfectly with the changes. I did make some one piece designs that take minimal support material as well. Since we had another model Lenovo tiny in the office, I decided to test fit that model. It does not fit due to the placement of the Feed on the case, I had added some material to stiffen the corners and feet for the second tiny are placed closer to the case edges. I figure I will modify the designs to accept either model before I call it finished.

Today I installed the M600 on my workbench with the Two Piece mount.

The mount files can be downloaded here:

https://www.printables.com/model/301500-lenovo-tiny-mount-m600/files

GBS Control

I came across a video on the GBS Control upgrade project for the GBS8200 boards. I had been interested in the GBS8200 back when I was doing my Commodore 128 RGBi/CGA to RGB video adapter. I had went with a SCART to HDMI adapter, as at the time that looked to be a better solution. It seems that device puts in a lot of delay though. It is useful to get “something” out of old RGB devices onto a HDMI compatible display, but when doing something like playing games the delay introduced is bad. I had not previously seen anything on the GBS Control project. The reason I had not used it at the time, was the SCART was to HDMI, where the GBS8200 outputs to VGA. The GBS8200 was a bit questionable too as it wasn’t super well liked in some circles at least.

GBS Control Project
https://github.com/ramapcsx2/gbs-control

Voultar’s Build Video
https://www.youtube.com/watch?v=1AVXhiTlmgo&t=2382s

GBS Control Case I used

https://www.thingiverse.com/thing:4946190

There is now the GBS Control project, which involves wiring in an ESP board to take over control of the board. This greatly reduces the delay introduced in the output. It accepts input from 15kHz (or 31kHz) RGB/HV (VGA), RGBS (RGB Sync often wired with SCART or 4 RCA jacks) and YUB (Component) and outputs to regular 31kHz VGA. There are DAC nonbuffered based VGA to HDMI adapters that are available very cheaply as well that are said to not introduce additional lag.

It has various features beyond near no lag being introduced. It has Scan Line emulation, various resolution outputs, downscaling video from higher resolution to lower resolution output. The controls are all onboard the ESP web interface, which you can use by using the default broadcast it does, or link it to your wifi network. It also lets adjusting position, size and various other things with the output.

In my case, I went with a compact case that was based on the build instructions I followed from a video by Voultar that introduced me to the project. With the case I used I don’t have the RGBS input accessible which is wired to a SCART port. It does seem though RGBS input is an option into the 15pin VGA style port with Sync on the HSync pin. HV means Horizontal and Vertical Sync, where RGBS just uses a single Combined Sync or CSync signal. The case turned out great, it is a near perfect fit.

I made a few changes compared to Voultar’s instructions. First, I did not add the resistor to the Sync line for the RGBS, as with it that affects the RGBHV input from what I read, so if I did do it. I would want to wire up an input option to switch between it being in place and disabled. On going over what that is about, I believe it is to be there when devices use TTL Sync a 5V Sync Signal instead of the 1V max Sync that RGBHV generally uses. The next change I made was when soldering in the ESP board I used angled header pins for the two ground connections, that provides a much sturdier connection between the two boards than a piece of copper wire or solder only. In most cases either just solder, or at least using a bit of wire will likely be just fine though. I like that if it gets dropped the pin headers will be a lot sturdier. I also connected the power for the frequency generator to a different capacitor, Voultar had misspoken what the polarity was in his video while wiring up the power, that let me wondering if he was wiring it correctly or not. I decided to then go with how the project instructions at gitub showed it wired in. Voultar’s wiring was a little shorter for the power, but it was also a little harder to get in at it with the soldering iron. For all of the power wiring I used heavier wire, and for the various other low power wiring I used solid core 30awg wrapping wire. I found that I had issues with the solder points on the two chips with the adjacent pins getting bridged, and had used some desoldering braid to get rid of the bridges. More flux would have likely helped me avoid bridging the pins. Voultar has certainly done that kind of thing far more than I have. Thankfully there are only 4 solder points to various chip legs. The capacitors were easier to stack than I expected and they turned out very well.

Mostly I want it to use the GBS Control with my RGBI to RGBS or RGB/HV converter project I posted previously for the Commodore 128 80 column RGBI (CGA) mode.

CGA/RGBI to RGBS Adapter: CGA/RGBI to RGBS Adapter Post

I have more recently made an update to that projects with a PCB and 3d Printable Case design.
Part 2: CGA/RGBI 2 RGBS PCB Design, Schematics, BOM

Part 3: CGA/RGBI 2 RGBS Board Assembly and Testing

Part 4: CGA/RGBI 2 RGBS Adapter Case and Release Files

I want to make a 5V output port for the VGA to HDMI DAC adapter at some point. I may do an audio passthrough option going in the front and out the back to connect into the adapter as well. I had thought of a power switch, but I use power strips for my equipment and generally turn them off when not in use. I have thought of a power LED as well, but still not sure on that one either. There was a version of the case that included putting the VGA to HDMI DAC adapter in the case. That was setup to remove the VGA output though, which I didn’t like. I have a number of VGA monitors I like to use from time to time.

For my first test of the unit, I connected it to the VGA output of a laptop. It passed through the VGA signal to the VGA output just fine. I then connected my Commodore 128 and my Digital RGBI to Analog RGBS / RGB/HV adapter. I built that adapter with the GBS8200 board in mind, so while it is setup it as RGBS + Audio through to the SCART connector I have configuration jumpers on the board. I changed the jumpers to NOT put 5V to the one pin which was to be the SCART mode detection. I also changed the Audio to not go to the HD15/VGA type connector and instead go to the RCA jack on the side. I changed the jumper to RGB/HV mode where it bypasses the Sync combiner circuitry on my adapter and outputs H Sync and V Sync. When connecting it up it worked great, I just adjusted some settings in the web interface to see how that worked out. The Scan Lines look pretty nice on it. I did not have any 80 Column mode programs prepared to use on the Commodore 128 to check it out too much at this time though.

This GBS Control is a baseline model build, more or less, for a bit more complex build check out the newer post linked below when I built a new unit and upgraded the one above to the new specification.

I have built another GBS Control and updated this GBS Control with some more connector options and features.

You can view that post here: https://hobbytronics.home.blog/2023/12/18/a-new-improved-gbs-control-and-upgrades/

TI 99/4a Recap

I figured I would make a post on the TI 99/4a I picked up awhile back. It was one of my first computers. I didn’t think of it at the time as a “real” computer though. I don’t even remember when I got it, but it was older and not current at the time, probably the early 90s. I wanted to get one and tinker with it like I have been with the other old systems from the 80s.

Really I am not sure I would recommend it yet. The system is so limited, I hate to invest in it. With a Commodore 64, short of a drive solution to get to and save data the Commodore 64 is complete. With the Ti if I want to do anything interesting, it seems I have to get a 32k ram expansion for it. That or stick to Basic and original cartridges. Many of the cartridges made now look like they require the 32k Expansion to operate as well.

Anyways I did get it, and I picked up some cartridges and even a tape player that I will look at in the future.

I did check the system out when I got it and took it apart. Inside it looked pretty good. The keyboard doesn’t work properly, it is one of the membrane types.. I am afraid also if I want to do much I will have to find a donor keyboard for it.

I did buy capacitors for it, there weren’t many.

Capacitors for the Mainboard. A few spares as well.

Initially I wasn’t going to get out my desoldering iron, but I quickly changed my mind before even getting the first capacitor out. I use an ECG J-045-DS desoldering iron. It is a rather cheap device, but it has done very well for me. I do keep thinking about and looking at those fancier units like you see so much of on Youtube. The ECG is a quarter of the cost of even the cheapest of those though and has done well for me so far. I don’t get it out much, mostly it takes awhile to get heated up and does take two hands to operate.

First was the power supply, with 6 capacitors. I cleaned the power switch with some Tuner Contact cleaner while I had it open, initially I wasn’t sure if it was making nice clean contact. I also replaced the LED as it was so dim that it was hard to see. The original LED had longer legs than typical, so I extended them with a piece of solid copper wire and then put heat shrink to insulate the legs. The original LED also had some heat shrink on the negative leg. I tested the power supply and it worked properly afterward, and the LED was much brighter, but not too bright. I also tested with the 99/4a board attached and it all worked fine. The voltages tested good as well.

I did add the zip tie to the largest capacitor after the picture was taken, although it was quite secure already.

Have to crack open the board. Two holding clip things and three bolts to remove this shield.

Then was the mainboard. That has 9 total. There is a single 10uF 35V, there are five 22uF 25V, and finally three 100uF 16V. To replace them I did get the five axial 22uF caps, but the 100uF I could only get in radial from the supplier I choose. The 10uF I couldn’t get an axial cap either so I went with a Tantalum instead, I could have picked up a radial 10uF though instead. When I did the Timex Sinclair 1000 I ended up getting some Tantalums for it as well.

Here is the board before. The Heatsink compound on the video chip there is replaced as well.

The worst thing of switching out from the radial capacitors was making sure I had the new ones installed correctly. Even the Tantalum is a polarized capacitor. The Tantalum marks the Positive, where Axial Electrolytic Capacitors mark the Negative. Then Radial Electrolytic Capacitors have a stripe with an arrow on it that points toward the Negative. So I did a lot of triple checking before powering up the board. I also checked my pictures of before and after to make sure I didn’t flip anything. That is why it is good to take pictures of these things. I then cleaned up the flux from the board and hooked the bare board up to test.

It didn’t power up properly after putting the capacitors in. That was an awful feeling, this is why doing such things are questionable. I checked and rechecked the board, I looked at each capacitor, checked if any were warm and possibly in backwards. I checked all solder points. I pushed in the socketed chips. Then I checked over the board again. I found a few flecks of loose solder, and one of them looked like it may have been shorting two points on the board. I checked again to see if there was any more on it then reconnected the board to the power supply and monitor. This time it came up normally.

I put it back together and checked it, well the keyboard is still awful, but it is working. I can play some Parsec just fine, well the joysticks are still awful. So it seems I have some more work to do with this one.

I pretest the new capacitors before installing them to make sure they are in spec. I also test the old ones I check how close to spec they still were. In this case I think all of the original ones are likely just fine. I just use one of the cheap atmega based component testers.

Still in the end, I had to open it for the new LED and well I say that was worth getting in place. It looks so much better with the new LED. Sure doing just that would not have been nearly as complex a task though. I also replaced the thermal compound on the video chip as well and do recommend that. The RF Shield was reinstalled the same as original. There is the later QI board that apparently doesn’t include it, or part of it at least.

My next project was a Joystick Adapter to use the Atari 2600 joysticks with the 99/4a. It is a simple enough project just taking some connectors and diodes. It did give me a bit of trouble though initially. Possibly a solder bridge issue again, or simply an issue with a poor connection at the TI joystick port, or an issue with not cleaning the flux from the board properly. I have it working now, I am just waiting on some more DB9 connectors to finish it up. I did also make a cartridge with a new pcb and eprom that I may mix in with some post at some point. I am really not quite understanding the way to use the new cartridge boards properly yet. I did get the homebrew remake of Pitfall on it, but I am not quite understanding how to set them up for different size roms.

Remaking Commodore 64 Cartridges

I ran into an issue with some old Commodore 64 Cartridge Roms that I purchased. I found 4 Rom chips with a single PCB for sale and purchased them. The PCB had a IC Socket on it to swap the chips around, all four chips worked on the board. I wanted to get them all usable again as full cartridges. I purchased some 3d printed cartridge shells at some point after that. There is also the issue that with the cartridge shells you can not use an IC Socket, it makes the chip sit too high to close the shell.

I decided to look around for some PCBs, but I couldn’t find any with the proper footprint for the original ROM ICs that have the 2364 pinout and not the pinout of the now commonly used 2764 27xxx EPROMs that the Modern PCB designs use.

I had not yet worked on any PCB designs. It is a lot of work to go from scratch for something like this if you aren’t familiar with it. The main issues are recreating the physical board in the right dimensions, the edge connector, as well as the proper size and placement of the hole to fit the case shells. With those in place it would not be too bad.

The original board after removing the socket and putting one of the ROMs on it.

I did find a project on Github with Eagle design files. I tried to start working on it, but just wasn’t getting it at the time. Part of my issue is I have four ROMs and one board already. I only needed three boards. I didn’t want to order in 5-10 PCBs to only ever end up using three of them. That would have been quite a waste. I expect to that I will not be getting any more 2364 pinout ROMs in the future.

It has been a good while since I put those chips in some ESD Foam for storage. I recently purchased some premade PCBs for other projects, which you can find the GAL PLA replacement post here which is one of the boards. Another of the boards I purchased was a 2364 to 2764 adapter board. The GAL PLA was so easy to put together as well as the 2364 adapter that I really wanted to get back to this project.

I looked around and had seen some of bwak’s stuff. I found his Versa64Cart over at Github.

https://github.com/bwack/Versa64Cart

It looked like a great candidate as it was available with the Eagle files. I haven’t used Kicad and the other project I found only had files for it. I wasn’t up to learning another program just for this project. Bwak’s design is also the most complete and has all required documentation.

The only thing I really had to do with bwak’s design was add the 2364 footprint beside the 27xx footprint and wire it up properly. I was careful and used the design for the 23 to 27 rom adapter as part of my reference.

https://github.com/SukkoPera/Open2327RomAdapter

I also did some other reading of cartridge schematics and reverse engineering the original PCB I had received with the ROMs. In the end I put on the 2364 footprint, I tried to use an existing Eagle Library that had it in it, but there was some issue with the footprint in it. That lead me to making a new footprint for it in the library using the standard DIL/DIP footprint. It is the oval pads rather than the minimal round ones that bwak used for his footprints though.

Here you see the 2364DIL24 added to bwak’s schematics

I also added a jumper between EXROM and IO2 to the board. The only reason I added that was because the Original PCB I have has them wired together. I have seen no other point at which those are referenced as being wired together. These specific ROMs are set for “GAME” and “ROMH”. EXROM is not used on these cartridges. I have found no reference of IO2 or IO1 used on any standard cartridges, maybe they are used for bank switching cartridges? If that jumper was connected AND “EXROM” was tied to ground, that would Ground IO2, which is probably not good. Beyond those changes the board is the same as bwak’s 1.5 design. This will let me use my remaining boards with some 27xx Eproms or EEproms.

In the end I ordered 5 boards from JLC PCB. You can see the IC2 and JP1 footprints below on the Gerber viewer.

The PCBs arrived 7 days from ordering them. That was manufactured, packed and shipped from China to the Eastern United States. They do say two weeks estimate, it was very impressive to get them so quickly. I got them for a bit under $20 for the five boards shipped to me.

Front and back of the board after it arrived.

If you look at my board compared to bwaks’s 1.5 the ground plane is different, I think I widened the gap between traces, as well as the additional footprint for the other socket is probably blocking some areas. The old boards had no ground plane it is not a big deal. I usually like to fill it out as much as possible though, for this it is not important.

Here is the first one I assembled beside the old board.

When they arrived I tested them against the original PCB. Everything checked out, the boards all looked correct with no defects. I did have to round over the card edge connector though, I expected that. I didn’t want the sharp edge there going into the C64. It was easy take the edge down with some sandpaper on a sanding block with a few passes across it.

The next thing I needed to do was solder on one of the ROMs, the capacitor and do the solder bridges for the GAME and ROMH pads. Initially it did not work, but that was because I forgot to do the GAME solder bridge. I did that and it worked perfectly. For the next three ROMs I soldered one onto the original board and prepared two more of the new boards for the last two. They all tested out and worked properly. The next thing was to put them into the 3d printed cartridge shells. That was easy enough, I will say compared to the old PCB, which fit perfectly into the printed shells that the new boards are slightly different. They are maybe .5mm to wide to fit, the hole for the screw must also be about .5mm to high or maybe even 1mm . This meant I had to slightly shave the 3d printed shell to fit the pcb into it, not a big deal. The hole placement means they are sticking slightly out of the bottom of the cartridge, but part of that is these cartridge’s have the screw about 1mm to low making that difference between the old board and the new ones a bit more pronounced. The old PCB even is about sticking out of these shells.

Here are all fully soldered up and ready to close up.

I am working on modifying a 3d printed shell design for my remaining boards, as those are the only ones I had. I had purchased them specifically for use with these four Original ROMs. I do have an Ender 3 Pro and can print them myself now. There are a number of designs on Thingiverse and other sites. So I picked up a few designs and started tweaking them with Tinkercad. The primary design I started with is a Stumpy type, it perfectly fits that old factory PCB, but that is the tallest it will accept. That is fine with me. It looks cute and takes up a bit less space, is quicker to print and takes less material. The problem with it is that the screw hole is was not placed properly, and the diameter of the standoff is incorrect, is also lacks support to keep the cartridge from rocking back and forth along it. I worked on it to get the screw hole placement correct, as well as fix the other issues with the standoff. I had placement corrected, and the length of the pins was great, the problem being the shaft was too large.. why.. So back to working on it. I did get it downsized properly now. It will use a M3 screw, so I reworked the face to accept a threaded brass insert. If I used the brass insert I can use M2.5 screws as well. The revised case now prints well and fits the cartridge PCBs nice and securely in the proper location.

Here they are closed up with my second test print of the Stumpy shell

The short shell is going to be for the remaining boards and possibly a few other modern cartridges. The original cartridge board fits it perfectly and is the longest that will fit in it. The Versa64 board a bit shorter so they fit well. I was thinking of making an even shorter version, but then it may get to be difficult to remove from the computer. I am thinking of maybe making a post about the shell if I do something interesting with it. It does not have the removable nameplate, which it really can’t as the screw mount is on the back of it. The cool thing about the removable faceplate on the shells I ordered is that a custom plate can be made to put in them. I had also purchased a shell for my Dual C64 Diag/Dead Test Cartridge which as a customized nameplate and opening to make the switch accessible.

The last thing I did with these cartridges was print up some labels with my Brother PTouch Labeler.

I thought of doing some printed labels on my inkjet printer, but they tend to fade as well as smear the ink if they get wet/damp. I have also done reproduction labels for cartridges using either label paper with the clear packing tape over them to protect them. Those sometimes the adhesive fails but it does usually hold up, the problem is more likely the packing tape adhesive fails and it starts to come loose. I have done it with paper and spray adhesive, but then after a couple years the spray adhesive has failed and the labels started coming off. Maybe I didn’t use the right adhesive spray. I did use clear laminating tape, and that seems to hold up well and stay on the label, but due to the spray adhesive they haven’t been on that long. Also the laminating tape I used is not glossy and is slightly hazy. I have also recently used a matte finish inkjet printable vinyl (see the RAD REU Cart). I feel that should hold up well, it isn’t quite the finish I like though it is durable. I mean the vinyl won’t have the exact look of an original cartridge label.

The PTouch labels have nice gloss finish and they stick very well. I expect them to hold up well. I have used them up for years for various projects as well as for work. They look nice for what they are, but are rather limited in the “art” and styles available.

You can see they aren’t any high value Cartridges. My projects are often about learning to do something new, or get better at some things I have done in the past. I like the bonus of getting something useful in the end. I may not use these games often, but I am glad that it will be easy to do so now. You can see how close the PCB is to the cartridge’s shell. Radar Rat Race is actually the original pcb, and even it is sticking out a bit. If I cared, I could sand down the new PCBs a bit shorter to be a more proper fit, but I don’t care that much. The new modified shells I have been working on are modified to fit better as they are.

This is just another quick easy project that I did. It is so much easier to put together a project with a proper PCB. I had toyed with the idea of designing and etching the boards myself. The ones I make were a very delicate and complicated project. I really don’t want to do any more of them anytime soon. Being a double sided board makes that much more particular in alignment. Cutting the boards correctly, drilling, etching… It is a lot of work, the lack of solder mask and through holes make it far more complex to assemble (not to mention not having the cartridge edge connector plated properly). I also design the boards with more space between traces when etching the boards myself to allow for the difficulty of keeping them intact and getting them to separate properly during the etching process , as well as going with as few through holes as possible.

I certainly expect to look into getting PCBs manufactured for future projects where required. The tough thing is for one off projects they are rather wasteful. I don’t want to buy 5 of them and only ever use one. Prototypes often end up with some mistakes, so I might order 5 and not be able to use any, or use one of them and have to rework on the board making it a bit of a mess.

Just a little addition. Here is a further modification of the Stumpy Shell shown above. The PCB is nice and flush in the shell. This is a C128 Dual Diag cart I have made up with one of the spare PCBs using an EPROM. The switch insert makes it reachable from the outside and the little red reset button extension makes it accessible. The EPROM is in a socket for this cartridge so I needed to make an opening for it. I find it quite difficult to get proper measurements for making the openings. There is a bit of trial and error making some test prints. An easier way may be to export the pcb design either to a scaled image file to use for a background or export it as a 3d model, which I did for my RGBI to RGB adapter pcb when making the case for it.