Commodore 64 Breadbin #2 Referb : 326298 Part 4 Finish up.

So I had to look into the keyboard issue with the * key. When opening the keyboard quickly get the shift lock desoldered. I have heard people tend to melt and ruin the switches. I had no issues with this one twice though I was very quick with removal and re soldering it. While I was in there I pulled out the two reworked plungers.

Above is the * key pressed, it is showing about 1.6k right there, but it varied above 2k, and if pressed really hard, it went down to around 700 Ohms. When pressed very hard it did register enough to work (sometimes).

Here is an example of another key that was working. aroub 125 Ohms with an easy press. I desoldered the Shift lock key, quickly as mentioned above, get it heated, and pull the wires and get the heat off of it. Then the removal of the screws again as before. Looking at the board and the plungers, I found the * key plunger had all kinds of white specks of dust of some type on it. I cleaned it off as best I could. The other keys didn’t seem to have the issue. I swapped that plunger over to the “British Pound” key, as I don’t expect to use that key much. I then installed the two replacements I had one going to the * key. I reassembled and then did the test on the * key again, and this time I got 70 Ohms, so that new plunger is working pretty good. I then reconnected it to the Commodore 64 and tested it. The keys were working, the “British Pound” key wasn’t as responsive as the rest, so the conductive pad on it must not be in the best condition, so it was good I moved it.

I did the “Soft press Restore” fix as well. The Capacitor Kit I purchased from Console5.com includes a replacement Capacitor for C38. From the site ” includes a 4.7nF capacitor for C38.  Exchanging the factory 51pF for this 4.7nF capacitor returns soft-touch function to the RESTORE key. “

I had not intially put it in, I didn’t know what that modifcation did actually. So I looked it up, and it appears to be a good idea to have. Without the fix, the Restore key needs to be pressed hard and fast to get it to register. This is because the way the circuit wired to it works, it is not looking for a press, it is looking for a specific change that is a bit more digital. So it can miss a simple press, the hard press causing the switch in the button to “bounce” a number of times and one of those bounces tends to then register with the computer. It is a simple enough fix to do. That was the last bit I needed to do inside the case.

Next I put the keyboard back in the case, and installed the new plates and reinstalled the LED.

It turned out looking much better than it did originally. It is painted, so I will see how well that wears on it over time. The new badges look very good, they are thicker than the factory ones. The factory ones are about flush with the ridges around them, these are up out of the ridges a little bit. It is the special Gold remade badges. I think it looks neat, I guess it could have been about as good with the standard badges.

Below here is my stock 64. It has yellowed/browned a little bit, but it doesn’t look too bad to me. The new paint is lighter than the other unit, and I think it overall is a little light, but it is a fairly good match I think.

Well I now have the two working C64s. I guess I will need to make a second power supply sometime. I have the parts for it except the case at this time. I guess it is time to move on to another project.

I would love to hear it if anyone knows anything about the 8Pin Video mod that this had received in the past. If there is any information out there as to how it was done. Certainly removing the original port, drilling for the new one. Cutting a few traces around it to separate the additional pins. Then there are the 2 wires that were added in. I am wondering if there would be anything else involved. I think there were probably two changes in the VIC II area, but I don’t know if they are related or not. I also wonder why this board doesn’t have R36, when I have seen others that do, and a few other changes. There seem to be a lot of variations, and I wonder if some of them are recommended fixes done by the service centers to fix issues with the systems, or make them more reliable?

After finally putting it together, I noticed the power LED had quit working. The lead broke off the bottom of the LED, so I ended up replacing it with another vintage used Red LED from my parts bin. Thankfully it looks the same as the original even when lit up. A new modern Red LED would have likely been a fair bit brighter.

There is a note that the Reset Circuit relation to the 556 IC is different on this specific model of board. The schematics are not correct for it, unless there are correct ones somewhere that I have yet to find. This means that the Reset button on cartridges like the Final Cartridge iii etc don’t work. As well as on the User and Serial ports etc. I may look into modifying the board so that will work. I want to do it in such as way that I don’t have to cut traces on the board though. That is why R36 is missing, it is normally the pull up resistor on the Reset line, where in this setup it is not used and only the 556 is.

Commodore 64 Breadbin #2 Referb : 326298 Part 3 Recap & abit

I had mentioned the video fix for this board in Part 1, but I don’t believe I went over it beyond mentioning. So here it is, Ray Carlsen recommended resistor change for improved Video. These boards shipped with an incorrect resistor installed in the VIC II area, that reduces the level of the Composite Video output. http://personalpages.tds.net/~rcarlsen/cbm/c64/SCHEMATICS/326298/early%20board%20weak%20video.txt

The resistor is R10 next to the VIC chip. His recommended fix is to add another resistor across the factory installed one. By doing this with the right value of resistor, you can get it set to the proper value. It is easier and safer to pull the resistor and replace it. Anytime you desolder a component you risk damage to the rather delicate circuit board traces. It can be done to look very neat as well.

You should be able to see the “stacked’ blue resistor overtop of the factory installed R10. This combination reduces the value to what it should have been. That did noticeably improve the video output. The factory resistor is 300 Ohms, the resistor that should be there is 120 Ohms. So obviously the signal is reduced. When putting a 220 Ohm resistor across the 300 that takes the value of the two resistors together to to give you around 127 Ohms, so that should be plenty close to the 120 that should be there.

So I managed to replace all of the electrolytic capacitors this C64. The Modulator was quite a pain this time around. Also due to that, I let my desoldering iron sit on idle hot for too long. The tip on it started to break down, so I will have to get a replacement. It worked well enough to finish the job though.

I know some people say replace the capacitors, some people say don’t mess with them if it is working correctly.

I say I hate desoldering the RF Modulator, but as far as something causing something I may see, well the modulator caps if they are going bad will affect the video output. The RF Modulator is tied in and affects the Composite output as well. Well that is what they say anyways, I really haven’t looked into it.

Above I have prepped to work on the capacitors. They are there, as well as my iron and desoldering iron, and solder collection can that I expel the solder into from the desoldering iron.

As I said the modulator was a pain. They had not “turned” the ears on the modulator to hold it in, they had bent over the small pins. I had to work the modulator loose by getting what I could off and putting pressure on the tab I had loose and hold it down while it cooled, then work my way around. I also ended up pulling the 3 square pins up out through the modulator top. That was my best bet to not lift traces. By heating them with my soldering iron from the top side inside the modulator, until it could put pulled up with my pliers that I was holding the pin with. Once they were out of the way, it was one of those pieces they bent over that was stuck in the end making it so I could remove it. I did loose some of the bottom pads, or do a good bit of damage to them where the can is soldered in with the tabs. In the end it doesn’t look to bad, the one that fell off I put back in place and reapplied solder. The one square pin lost the narrow pad from the bottom, but not the through hole apparently thankfully. It was the audio pin and that is why I decided to just heat and remove them pulling them up out. It was a good idea. They are a tight fit, so once I had them out, I ended up using a small file to file off the old solder so they would fit again. You don’t want them loose, because they are double soldered, you risk the solder loosing contact then.

After getting the modulator off, I replaced the capacitors in it, then went and replaced the remain ones before reinstalling it.

I cleaned a the tabs and such on the modulator and the holes in the to board to make sure it would fit back in easily. After that I reinstalled the cleaned up pins into the modulator. In the picture the center one had some solder on it again as I had started to reinstall it but pulled it back off.

I actually pulled it off, so I could check where the traces went under it, for those three pins. I wanted to be able to make sure they were making good contact before finalizing the work. So I reinstalled it, but I did not solder any of the tabs back tight before testing.

She still worked after the replacements. I haven’t tested the Keyboard or Sound though I guess. Yes I was wearing my ESD Wrist Strap. The blue mat is a grounded ESD soldering mat.

After it tested good, I then twisted the tabs on the modulator and soldered all of that back on. I did a bit of cleanup of the flux and reinstalled it into the bottom case. So now I need to do that keyboard work so I can put this all back together and use it again.

The new tips came. I am going to be more careful about leaving it idle when it is not in use.

Here is my desoldering tip. I see this happen with Copper based tips, I guess this is Brass looking? If the hot solder is left on them it starts to dissolve the metal of the tip into the solder. It is replaceable, and I like the iron so I will see about ordering in a replacement for it. Once they start doing that they keep breaking down. Other types of tips will just burn the plating off and then will quit accepting solder and not transfer the heat properly. I will not leave it idle like that while it is on again. It was while I was working with the modulator, which may have taken a hour. I was taking care to not wreck it, so it took awhile.

Beyond the modulator it was an easy recap. Most of the capacitors I pulled tested pretty reasonable but not all.

Three of the 10uF capacitors tested with almost no capacitance. Otherwise they were a little inconsistent and all of them measured above their stated values. The new ones are closer to their rated values. With those three odd ones, I feel it was worth it.

Well on to revisit the keyboard. I really don’t want to take it apart again, but the * key is kind of important. So I will get that in the next and likely last post on this refurbishment.

Commodore 64 Breadbin #2 Referb : 326298 Part 2 Case Repairs

Well I am getting back to the second Breadbin repair and cleanup as I finished up another couple projects I had put it on hold for.

I did get one of Birt’s C64 Case Saver kits to repair the damage to the case:

https://www.soigeneris.com/commodore-64-caser-saver-repair-kit

I didn’t think I could do much with the tab, and with the two cracked screw standoffs, I figured it was worth while to get it. I will have to say I am very happy with the fit and quality of the parts. I attached them with some JB Well 4400psi Epoxy.

I am doing another coat of paint on the lower portion of the case, partly in hopes of a sturdier finish, but also due to that crack that showed at one of the Din ports in the back. I had glued it, then I used some Epoxy on the inside to help it as well. I then used the White Putty in the crack to help blend it out.

With the top I cut the broken portion of the case tab off. It was the narrow one. I then installed Birt’s replacement tab. It was a perfect fit. Per his recommendation I did slightly round its edges and the two remaining tabs. I also put his parts on to reinforce the cracked screw standoffs in the top. I again used the White Putty on the outside of the crack in the right front corner of the case to help blend it out for the paint. While I had the epoxy, I decided to reinforce the inside of that crack with it as well.

The paint turned out really well. I put on about 3 coats on it. Krylon Fusion All in One Matte River Rock.

I ordered in some reproduction badges for the top of the case. Well I went with the “gold” model type labels. This thing is an odd machine, and the reproduction badges are great, but the way they are made is a bit different so it was not going to look exactly original from close up. So I am happy to make this rather neglected, and somewhat unique 64 look a bit more unique.

I have just finished replacing the electrolytic capacitors on the board. That will be posted in Part 3. The modulator was quite a pain this time around.

I still need to look at the * key and see if I can get it to be more responsive. The two “repaired” plungers are a bit off, the height is just a little wrong. I am going swap them out and keeping them as future spares. I need to open the keyboard to check out the * key anyways, I might as well switch them. I may redo them with epoxy sometime and try to adjust the height a bit more. I don’t know if that will be Part 4 and hopefully end up with it finished up.

Bartop Arcade Build Part 2

This is part 2 of the Arcade. The first post has the Arcade in a good working condition. This will cover some of the final touches.

So I did a bit more work on the Marquee. I did a bit of work on the graphic design. I am in no way a graphic artist. I had downloaded some logos to do the initial graphic. I found some better ones to use and made some other changes to it. I then printed it out on my inkjet printer onto 3 sheets just like the previous test one I did on a black only laser printer. It turned out pretty well, I couldn’t do a full color graphic though. I think I will leave it at this paper graphics for awhile anyways.

For the Marquee there really aren’t any hot spots. I was thinking doing a frosted piece of Plexiglass behind the marquee to handle any hotspots, but that turned out to not be needed (with the paper that is). It is a little brighter than I think I want it, but I didn’t find it too distracting while test playing it. It is quite hard to photograph anywhere near properly though as bright as it is. I have at this point decided to not make a dimmer system for it. I have a couple of workable circuits that I have used for that in the past, I just don’t want to take the time at this point, when the biggest issue is taking photographs of it.

For the LCD I wanted to make a bezel/cover that went over it. To do this I put some 1/8th inch strips up the sides of the cabinet to rest the Plexiglas against. It slides up behind the Marquee bottom board, between it and the top edge of the LCD itself. The strips up the sides are a lot like the ones that were in place on Mike’s build in the video. I wasn’t sure what they were for in his case, they may make it to have very little gap on the sides in his case? He did not cover the monitor with Plexiglas so I am not sure, he also had a small board along the bottom above the control panel, which I omitted due to the Plexiglas. I fitted the Plexiglas so that it just meets up with the back edge of the control panel. It is not held along the bottom and just goes up against the control panel board, so it can flex and make a gap there a bit. I may secure that in some way in the future, but currently it is minimal, and I do not want to make it difficult to remove the control panel if I need to.

Above is the Plexiglas I was cutting for the screen. To cut it, used a board and metal angle. I was cutting from the side on the right side where the knife is laying. Because the Plexiglas had a bad edge from when I purchased it, I needed to be sure to get one good long cut. This stuff is very hard, it is not the softer type. It likes to fracture/crack. I managed to get a very good first cut on the top edge. The next cut, which I was doing in that picture really cracked up the edge. The last cut, cutting it down to the right width, that cut went very well thankfully. I had 1 factory edge and 2 cut edges exposed that turned out pretty well. It was very slightly too wide, to get it down to the right width I used some 180 grit sandpaper and a sanding block to get it just right.

The next part after fitting the Plexiglas was to get it in the final position with the LCD in place and the Control Panel in place. I then used a marker to mark the corners of the LCD behind the Plexiglas. I removed the Plexiglas, and monitor. I placed the monitor on the bench facing up and then placed the Plexiglass back over it using the marks I did while it was in the Cabinet to get a good view and check the marks were correct and centered properly. Once I was sure I had the corners marked that I wanted was to take away the monitor and flip the Plexiglas to the back side. From the back side, I cut into the protective plastic with a fresh Xacto blade around where the monitor will be placed, and removed the outer portion. This left the “monitor area” covered and protected. I also kept the protective layer on the “front” side as well. Then I used some Gloss Black Rustoleum 2x Ultra Cover paint, which is to work on Plastic as well. Painting that on the outer rim that I exposed by removing the film from it. This paint is on the back side of the plastic not the front, I have done this before for other projects. It leaves with a super gloss finish that won’t be touched. The back is not flawless, it is not 100% opaque (with more coats of paint it can be made fully opaque), but it is opaque enough for this use in my case with the single coat. Viewing it from the front the finish is flawless.

Above is the panel after painting it once I removed the protective layer from the inside. This reveals where the monitor will now be behind. The paint does take awhile to dry well. I wanted to make sure it was good and dry before installing it, I didn’t want paint lifting where it meets the strips on the side. The final installation it went well, it is held tightly in place by the monitor at the top edge. I have a fair bit of pressure on the board there from the Monitor to get a little more tilt than the base will give on its own. I was very happy with the result.

Above you can see the thin strips the Plexiglas will rest on. After installing them I painted them gloss black to blend in. You can also see the door latch and spacer block to keep it from moving much. The little block at the bottom of the door is to keep it from going in to far, there is another stop block on the top corner as well, but it is out of view in the picture. The round speaker grills are again easy to see here as well as the chrome volume knob on the right.

Above is the Plexiglas installed with the monitor behind it before I removed the front protective film. Yes those are the wires leading to the front panel, when I reinstalled the panel I wrapped them up so they weren’t such a tangled mess. The monitor is there sitting on the blocking it is screw into the cabinet with. I have some pressure on the marquee bottom support board to get a little more angle out of it, as well as the block is a bit angled itself. I would have used the VESA mount board in the cabinet except this monitor doesn’t support VESA mounting. So there are two screws in the back of the monitor base going into the block there. The block is built up so that the monitor was at the height I was going for, and it is secured to the bottom of the cabinet with 4 brackets with screws. I used brackets as I have it set so that I can get to the screws if I need to remove the monitor rather than gluing it in or putting in screws from the underside.

Above you can see the speakers installed before securing the wiring, the power supply board has been removed, or it would be attached there at the black and red wire, which now lead down to the 5Volt output on the Meanwell power supply below it. The other picture shows more of the internal wiring that goes to the Raspberry Pi, the two front mounted USB ports, the USB power cable which goes to the Meanwell 5Volt output as well. The safe shutdown/power up button wiring is there as well as the speaker input wiring. I ended up plugging the speakers into the Monitor’s Audio Output as I am using HDMI for Audio off of the Pi. If I had plugged into the Pi I would have needed an audio ground loop isolator, because I have the Pi and the Speakers powered by the same power source. I had to do that with my Pi1541, and I had tested on this and had the same issue. Using the Monitor Audio Out that it gets from the HDMI input, lets me eliminate the need for that.

Here is the back with the door latched of course. There is a fair gap at the hinge side, but with the wide hinge that does not show. I should have made it just a little shorter, it rubs easily, but I hope to not have to open it much. I also hope to not loose the keys.. You can see a bit of the run in the paint at the top, but it is on the back and shouldn’t be seen much. Overall I have to say the paint turned out pretty good. There at the top, there is that extra T Molding strip on the Marquee Top. I think it looks nice and provides just a little ventilation due to a narrow gap where the boards come together there, and that little bit of excess still gave me enough with 20′ to do it. The Plug/Fuse/Switch unit in the back there can be wired a few different ways. The one I have has a lighted switch, that switch could be wired either as an Always On light even when turned off, or it can be wired at only to light up when the power is on. I have chosen to wire it so that it will only be lighted if the power is on. Some of them do come with a black switch and those don’t have lights in them. You could just switch the Hot line so that the light would not come on then because if the Neutral isn’t there it won’t light up. With the plug unit, again be certain they are secured well and not loose, a loose wire can cause heat and melting and potentially fire. I nearly soldered used solder and heat shrink on the plug unit for that reason, but I didn’t as then I would have to desolder it to ever remove the plug or power strip.

I had to edit the above picture, as the Marquee keeps washing out almost completely. That is the Marquee that is in it, I just took two pictures and over laid it over the lighter cabinet picture. The Marquee looks a little better in the picture than it looks to look at it. I did not remove the protective plastic from either side of the Marquee Plexiglas yet though. It turns out to be very hard to photograph this cabinet.

Above is the Pi 3B+ as it is sitting in the cabinet currently. I would have taken it out of the case and mounted it to the cabinet, but then I have to rig up a fan to it then. I may do that later. You can see in the picture the wires coming down to the GPIO Pins. The round momentary button on the back of the case there is wired to GPIO3 (Physical Pin 5) and Ground (Physical Pin 6) of the Pi 3B+. GPIO3 is a pin that will by default wake the Pi from a the shutdown/halt condition. Simply editing the /boot/config.txt file and adding the line “dtoverlay=gpio-shutdown” will activate GPIO3 to be a “shutdown” button. You can change the Pin that it will use for the Shutdown by defining the pin in the dtoverlay value. That will then make the other pin be the shutdown pin, but it won’t move the “wake/start” function from GPIO3. The Pi will start the Shutdown process as soon as it has been pressed. Once the Pi has shutdown, you can start it back up by pressing the button again (as long as you are using GPIO3 (Physical Pin5). There are other ways to set this up, they can include a delay where it will make sure the button is held down for a period of time, which could be handy to have. I went with the easiest option though as I have the button on the back where it is not very likely to get bumped while the cabinet is in use. I found the instructions on how to set that up on this thread: https://www.raspberrypi.org/forums/viewtopic.php?t=217442#p1337231

I did do just a little testing firing up one of my old 2600 games. Asteroids, I managed to roll over the score easily. I was playing on the easiest level though. I went back and started with the next level and that did not go so well.

I want player 1 to be the left side, and player 2 to be the right side. I found after reinstalling the control panel that they were backwards. To correct his, I unplugged the joysticks from the USB ports on the Pi and swapped their positions.

The Pi is accessible from the back door if I need access to it. I can also easily remove the control panel. I have two brackets on the back of the Control Panel with screws into to keep it in from coming off. I briefly thought of making the SD Slot accessible on the Pi from the outside like I did with the Pi1541. It is a bit much with 3/4″ material though, and I don’t want the card to be to easy to remove and loose. If I want to add anything to it, I can by using the Wifi connection, or open the back door to pull the card.

The Marquee top has some brackets and screws that I used to secure it towards the cabinet. I want to have it remain removable to easily access the Marquee graphics etc if needed. If I do another cabinet I will likely change the Marquee area. I am thinking of making it set back just slightly then use painted angle metal pieces to hold the Marquee in place. This will mean there would be no T Molding across the Marquee Top and Bottom. It will make it so much easier to install and support the Marquee though. That seems to be how the real Arcade machines did it as well, at least quite a few I have seen. I think I will still use the light box design behind it. That worked great, and the Aluminum will distribute any heat from the LEDs very well. They are using nearly half an amp at 12volts, so there is some heat there, but not a ton over all that rather large area.

So one may ask, about what this project cost to build. In my case I believe that I have a little over $250 wrapped up in materials. I am not counting the Pi 3B+, SD card, Monitor or Power Strip. If those were purchased as well, I would have been looking at around $410. I did not include cost of Wood Glue, Brads, the bit of Aluminum sheet, as those are supplies I had around, as well as the corner blocks which are basically scrap wood. I did purchase a few tools, a 30mm Forster bit, a Router Slot Cutting bit, and the Edge Guide Clamp, those items add up to around another $100. I now have those tools for future projects though.

I have enough MDF, LED strip light, hinge, Plexiglas and a few other bits for a second cabinet. I would need to buy some T Molding, Controls, the Pi, Monitor etc though. I would like to find a better way to cut the Plexiglas, the scoring it with a knife doesn’t work very well on this hard stuff, at least for long cuts. I managed to get it cut, but it could very easily have turned out bad. It really isn’t “Plexiglas” brand that I picked up, I think I have had some softer stuff in the past that was easier to cut, but that wouldn’t hold up for this usage. I don’t remember Lucite cracking like this material has for me, I have used that in the past, it is pretty good stuff, although even more expensive. It has been quite a long time since I worked with it, so I don’t know if it was all that much more fun to work with.

In the end the cabinet is still difficult to photograph, at least with the camera I have. I guess Gloss Black is not much fun for that. Although it is not flawless, I am quite happy with the final result. Above the Plexiglas over the LCD is quite obvious though and gives a good view of how well that turned out for me. The little mix of colors of the buttons is that I purchase a Blue and Yellow set, and already had a white set. I felt mixing the colors gave a better effect.

Bartop Arcade Build Part 1

I have been wanting an arcade machine for a long time. These days there are a lot of options out there that make it easier to make your own. I purchased the Bartop Arcade plans from The Geek Pub http://www.thegeekpub.com

It has been a lot of work. I mostly used a 50 In Clamp Edge And Saw Guide and circular saw to cut out the pieces. For the arc on the side cuts I used a jig saw, and I cut them out clamped together to get a proper match. With a table saw it would be much faster. I optimized the cut layout from the original to help me get some larger extra bits to work with in case I needed it.

I essentially cut out the parts the same as the plans. In the end I found there was an issue with the Marquee Top (B) and Top Door Frame (F). The Marquee Top and Top Door Frame should have been cut at an angle to meet nicely in the back. To correct this, I shortened the Top Door Frame a bit so that it just let the Marquee Top clear it. I then also added T molding to the back side of the Marquee Top, as it was now going to be an exposed edge. If I made another Arcade, I will be changing how I end up cutting that out. I may also make some other alterations to make it easier to put in the Marquee itself.

After cutting out all of the pieces, I did sand them all on both sides. You can see in the picture above that I laid them out on top of the second half of the 4’x8′ Sheet of 3/4″ MDF. This does only take half a sheet to make this unit. One could argue that a little in that you may need more to get the blocking strips for the various corners if you use them (which I did use).

Before assembly I did use a slot cutter in a router for the T molding. I used a 1/16″ slot cutter. I took the pieces outside and use a clamp to clamp them down to my saw horse. Then it only took a couple seconds for each on to put in the slot. The biggest thing being to get the slot bit set perfectly center. The other thing, use a mask for this, it was awful the first one blew back right at me. Beyond that it is easy to put in the slot.

I assembled the unit with corner blocking, glue and brads like was done by Mike at The Geek Pub in his video. Other methods could be used, if you want you can use screws. He mentioned Pocket screws, which I do have, but I didn’t feel like trying. They are quite expensive screws and I don’t like to use them when I have cheaper options. I figured if I wasn’t careful they could split the mdf as well. If I used them I was probably going to still use glue too.. The blocking made it very easy to assemble. I was looking at trying to do it without putting in the blocking, but that made it very difficult to get good alignment. The blocking makes it stronger too with more surface area for the glue. I did have some strips of pine that I had salvaged and used them for most of the blocking.

I realized that I had not drilled for the speakers in the Marquee bottom board until after I had it installed. I used some Logitech 2 piece speakers for the arcade. Removing them from the shell, they have some 2″ speakers in them. I used a 2″ hole saw to make the holes in the board. I also had to drill for the volume control access. I removed the power Led from the board. While the board also had a Headphone jack on it, I decided it wasn’t practical to do anything with it. I needed a longer knob than the one it came with. That is also something I would do differently. Had I not already glued the board in, I would have carved out the back so I could have used a more standard length knob.

I then rewired the speakers for installation in the cabinet. I was going to reuse the original AC power unit so I setup to be able to put it in as well.

These speakers operate off of 5Volts DC. They make this speaker set as a USB Powered speaker as well so I guess it just happens to use the same board? I didn’t like the exposed AC board inside the cabinet. I went with a Meanwell dual voltage power supply for the cabinet. This let me run the Raspberry Pi and the Speakers both off of the 5Volt DC on it. It also provides 12Volts DC, which is for the Fan and the Marquee lights.

The next part was the primer. I used the recommended Rustoleum Filler Primer. This stuff is pretty neat stuff. It has a filler product in the paint. It looks like it is fuzzy, but it sands out amazing.

Don’t skip primer, It just won’t work if you are using MDF. I waited until the next day to sand it. I used I think like a 220 grit paper to take off the fuzz. I then followed up with some finer paper. From there I wiped it down with paper towels and brushed it well, then use a microfiber cloth to wipe it down. Then I painted it with some Rustoleum gloss black. I let that dry a day and took some 3000 grit to lightly sand any little bits that were in the paint. The paint I used is the 15 minute dry type to help keep the dust, bugs etc blowing into it. I found that it was better to do a single coat that caught most of the dust that got in it. Then I came back and did 2 more light coats after the 3000 grit. That later paint didn’t end up with as much dust in it. The last thing I did with the paint was a Rustoleum Clear Gloss coat. That stuff dried very fast, it was quite different and had a lot of over spray. When I was doing the painting I was mostly wearing a mask as well. I was thinking of trying to polish it, but I decided I wasn’t going to be that crazy about it, and I wasn’t sure I had the clear on thick enough. I used 2 cans of primer and about 2 cans of the black. The clear coat didn’t take even a can. I did end up with some runs on the top back door frame piece. I did use one of those spray handles for the cans, as seen in the picture below. That makes it much easier for me to get a decent finish and better control. My wrist can’t handle pressing a spray can nozzle very much at all.

Well, there were two other things I didn’t get drilled before the initial assembly. The first being the “safe shutdown button” for the Pi on the back beside the power jack. The other being the USB ports in the front right there.

I had to backbore the Shutdown button here by the power port. The USB on the front nearly needed it. The USB port insert I used goes into a 30mm hole it barely has any threading with the 3/4″ MDF, but it was just enough.

The T molding isn’t too bad to do, but I wish it had went a little better. I got 20′ and I used all but about 18″ on this cabinet. There would have bee that bit more if I had not put that additional piece on the back side of the Marquee Top. I am assuming I had the full 20′ I was to have received, but I can see how it did use that much. I just did it like Mike showed in his video, back cutting at the corners, and trying to put it in strait with a rubber mallet. I had a few issues here and there. I had some problem with snagging and pulling it back out when moving the cabinet. I will be adding some feet and that should prevent it from dragging the edges too much in the future. I did put a little glue toward the ends to help hold it if it snags a bit.

Here i have the control panel assembled and the USB ports installed after finishing the Clear Coat. I am using a Dell LCD I have had around, and been using on my computer as my secondary monitor. It was almost a perfect fit, and had HDMI input and audio output (no speakers internally). The control panel layout is in the plans as well, the template prints out on multiple pages that get taped together. I used a spray adhesive to hold it on like Mike suggested. It was a bit of a pain to remove all of the adhesive after the fact ( I used a different product than he had so maybe it is harder to get off). The paper came off fine, but some of the spray stayed behind. I later used another of the templates (well 3) and was careful to use as little spray as I could, that turned out better. I used the 2 player template and omitted 2 buttons, 8 was enough for me. You can choose to use the buttons you want. He also includes a 1 player layout template. The buttons I used are the pop in kind, so with the 30mm hole they went right in a perfect fit. The small buttons I didn’t have the perfect drill bit for, so they were slightly loose, and a little glue on the bottom edge in a couple places to ensure they don’t move on me. Do drill the holes I used some Forster bits. The 30mm for the big buttons and the Joysticks, and the smaller one for the smaller buttons. They do a very nice job, the butterfly bits I have are way to aggressive, but they are a weird type. I used the bits in my cheap Harbor Freight Drill Press, which made the work go so nicely.

The one trick with the controls is they need to be wired identically, as the Pi can get confused if it has two of the same model of controllers with different layouts.

Here is the first time I fired it up. You can see the speakers in there. This was the first time I tried it out.

Here I worked on the Marquee light. I am using 12Volt White LED Strip light. I decided to build an Aluminum Light Box for it. I really didn’t have a good way to mount the LEDs otherwise, and I didn’t want all of the light going out other areas of the cabinet.

Here I am using clamps and a board like a break to bend the aluminum. It worked ok.
Here is the box. I was neater but I had it slight long and had to compress the ends down a bit.

Above you can see the LED Strip. I put it on the Sides not the bottom. This helps with Hotspots. In such a close space the points of light off of the LEDs would make hotspots all of the Marquee otherwise. The box is 1″ deep. You can also see the Speaker grills and volume knob. The Speaker grills are made from some 2″ desk grommets from the hardware store, and then covered in some speaker cloth (salvaged from an old speaker box I had).

Above you can see the back door. The door was slightly taller than it should have been, possibly a little wave and variation in my cuts for the back. The bigger thing was the that I turned out to be somewhat narrow, I am not sure if I didn’t measure properly or something. The door Frame pieces seemed to all go just fine, but there is a bit more gap left and right. So I would watch for that if I make another. I wasn’t going to use a piano hinge for it, but due to the gap that was the only way I was going to be able to hide it well. I also decided to get a lock, not that I wanted to lock it, but that was the most elegant looking latching method, and also when moving I didn’t want a “semi-secure” latch that may flip open accidentally. The holes were drilled with other templates in the plans. The bottom is the 80mm fan pattern. The top two are the hole for the suggested speakers, I felt I wanted more ventilation so I used them for additional venting on the door. Here you can also see the door once it was installed with the fan and latch assembly. The modification to the door frame top that I mentioned above did have the added benefit of adding some ventilation as well as there is a small gap there now. I like that bit of the change as heat will build up and would have caught in the top had it been sealed up. You can also see the wiring going to the power strip I put in there. It is wired directly to the rear power jack. I had it around and it was easy to work with. I didn’t want to buy an electrical box and wired it up that way. This is a surge protector as well, not just a power strip.

The power jack includes a switch and fuse. I like it, but some have had it has issues with melting. I could see that if the connections were a bit loose, that causes the conductors to get hot. So I can see it happening. The Safe Shutdown button for the Pi is also installed there. The button is wired up to the gpio on the Pi and the Pi is setup to use do a safe shutdown if it is pressed. It will also wake the Pi after shutdown if pressed again. I will cover that in Part 2, it is quite easy with the Pi 3.

The Marquee just has some paper in it behind the Plexiglass to test the brightness. It is a little too bright. I am probably going to dim the LEDs a bit. I am not sure how I will do that but I have an idea. That will be in another post though. So this is Part 1 of at least 2 parts.

I have to finish the Marquee, if I make a dimmer for it that will be covered in another post. I am also going to put Plexiglas in front of the monitor to hide it. Once I have the Plexiglas cut for the front of the monitor I will be able to mount the monitor in the cabinet. The Monitor I have does not have a VESA mount, so I have secured it to a built up block that I will secure with some brackets to the bottom of the cabinet. I just don’t know the exact final position until the Plexiglas is in. The Marquee top needs secured as well, but I have to finish the Marquee first. I do intend to keep the Marquee Top removable if needed, but not just friction fitted like it has been so far now. The Pi is also floating free in there. I have been thinking of pulling it out of the case and mounting to the cabinet as a bare board, but I do want to put a fan on it still if I do that. To start with the Marquee I will probably finish a design for it and reprint it on my inkjet printer instead for some color. I may get proper marquee made professionally later on. If I do, I will probably get some side graphics for the cabinet as well, but not full side covering graphics (not after the T molding is installed).

Commodore 64 Breadbin #2 Referb : 326298 Part 1

I picked up another Commodore 64 breadbin model. It had a rough time in storage from the looks of it. The system has been in a damp dirty storage area, there were several of them being sold by the same person, in similar conditions along with some other old 80s era computers like Apple ii systems. I guess they were stored in a basement somewhere that had some real water/moisture problems.

As you can see from the outside it is a bit dirty, and some keys were missing. This was I think the second best looking of the batch. Below you can see the inside, the paper shield was a mess, black mildew along the bottom. A good bit of dirt inside. After seeing it in the bag, I decided I wasn’t even opening it inside. So I took it out back and opened it there. I removed the cardboard shield and it went strait to the trash can. The case we taken apart and hosed down to get the worst of the dirt off. I wiped the keyboard down a bit and the board before taking them in. The case parts went it the tub and got a really good scrubbing.

I removed the RF Shield and cleaned the board with some 91% IPA. It turns out to be a bit of an interesting board. Yes the screws are mostly rusty, the RF Shield and Cartridge port plate tells a tail of too much water too. On close inspection the board looks ok for the most part, the legs of some of the components are rusted, I clipped a them and the tips just fell off. This board has obviously been worked on in the past. The inner cardboard sheet that was above the bottom RF Shield went strait to the trash, it was about as awful as the upper cardboard shield.. I kind of like this brass looking shield, but without the cardboard to go with it, I won’t be reinstalling it. I don’t care enough to make a new cardboard piece.

You may notice the wires in the above picture. This is a 326298 Rev A board. An early board that only has the 5 Pin Video port. This board was built in 82 based on the unsocketed chips. The board had extensive work done to it. All of the main chips are socketed. They are all dated second half of 84. The 5 Pin Video port was replaced with a full 8 Pin Video port. There are two wires running off from that port, and various cut traces on the top and bottom to separate out the additional pins. I think in the VIC II area there were possibly some other changes. The VIC II area cage was (and still is) rather rusted as well as the RF modulator top plate, and the RF Rca port was all rusted.

So after the ipa bath I hooked up the board.

It worked, no issues. Next I tested the keyboard, it worked, minus the two broken keys. Some keys were not very responsive though. I did a full teardown of the keyboard to clean it properly.

I first removed all of the keycaps with my keycap puller. I recommend one, they are rather cheap and good insurance to prevent breaking the old plastic. I next desoldered the wires on the ShiftLock key. I had removed the tape from around the keyboard, as you can see, to get to the screws under it. After removing the screws the board lifts off, and you can see the plungers then.

I took out the plungers and put them to the side, then took the keyboard frame and sent it to the tub and some warm very soapy water. I also soaked the keys in the soapy water. Then scrubbed the keyboard and keycaps with a toothbrush and rinsed them well and dried them. I also took the springs which were dirty and some were rather rusty. I put the springs into some White Vinegar. The Vinegar removes the rust, it does make the metal a bit dull looking. I expect if you leave them in too long you may break down the metal too, so I kept checking on them. They cleaned up well, the worst of them you could tell were actually pitted but were still in working order. I then washed the vinegar off with some water and dried the spring as best I could. I placed all of that on a towel to dry properly.

While that was drying, I took some IPA on a qtip and lightly wiped the contacts on the circut board. We don’t want to remove the conductive coating. If you clean too much of it off they keys won’t work. Next I took the plungers, and wiped the shaft part with a damp cloth to get any dirt off, I didn’t wipe the contacts on the plungers, they looked pretty good. They were mostly clean overall due to being covered by the keycaps and in the keyboard frame holes.

All of the good plungers and two broken ones.

Well, I had watched Perifractic’s Lego 64 videos, and I got an idea to try on the broken plungers. They did still work, as I had tested the keyboard with them, they just won’t hold a key now.

So I found a Lego laying around. You see the full piece I started with there in the lower left. I cut it in half, cleaned the plunger up and fited it to it. I shaved it down to go into the plunger shaft a little for more surface area and strength. Then I glued it in with a combination of Bondic and Super Glue gel. I DID have to file down the Lego piece, it was too large and the Commodore Key cap wouldn’t go on it. I used my small Diamond Grit Needle Files from Harbor Freight (they are just small files, I got the Diamond Grit ones, they seemed to work well for me on plastics). I will say that the glue doesn’t hold well, these tops will come off. So it isn’t a great fix, but I think it will work. I am still waiting on replacement Plungers and springs for the keyboard. I put the one plunger back at the British Pound symbol location, but I put the other at another key that is less likely to see much use. The 8 key gets a lot of use.

Here is the keyboard frame after reassembly.

Here is the keyboard back together back in the cleaned upper case. I tested it and it all works. The * key doesn’t work very well though.. When I get the new plungers in, I will probably remove the circuit board again and check that key. I don’t know if it it is the plunger, or dirt, or the contacts on the circuit board. Other than that and the missing caps, the keyboard was quite responsive, better than my other C64. That one I did not remove the board to clean the contacts. Removing to swap the plunger and check that key isn’t too bad. I will only have to desolder the ShiftLock key and remove the screws. The plungers that I am not working with will all stay as long as the keycaps are still on the keys can’t come out.

I does look much better than it did, but it is very streaked. The Power LED plate was actually corroded to the point much of the paint was lifted and flaking off. Corroded Aluminium.. Ya, I guess a good bit of moisture for a long period of time. I plan to get a replacement Badge and maybe a matching Power LED plate, I just don’t know what I want to go with.

Next I started on some preventative maintenance as well as rust removal. I had already removed the rusty tops of the VIC II area and the Modulator top cover. I then desoldered the Cartridge Plate and the VIC II cage which is rather rusty. I did alot of cleanup on the RF Modulator cover and Cartridge plate. A combination of wire brushes, sanding, and polishing with the Dremel etc. To remove the stickers easily, I put a little WD40 on them and let it sit. When I was done they were pretty decent. I tried some Vinegar on the RF Modulator cover, but that removes the protective coating that was still on some areas of it, so I stopped that. I did soak all of the rusty screws (basically every screw in this thing) in the Vinegar to get the rust off. I also removed the Fuse holder pieces, and fuse, they were quite corroded. I placed them into the Vinegar as well (well not the fuse). The Vinegar did clean the corrosion pretty well off the Fuse holder, but it left those areas black, I then polished them back to a shiny surface before reinstalling them. When all the rust was off of the screws and Cartridge plate and RF Modulator cover, I put some “Teflon Non-Stick Dry-Film Lubricant” on them. Not to Lubricate them so much, but to put a protective film on them to help prevent them rusting again. I did the same with the keyboard springs after they were dry. I don’t use the stuff on plastics though it puts a white film on that is hard to remove. So I put it on before putting them in place.

I resoldered the Cartridge Plate back to the board. I also touched up some solder points on the board. The VIC II cage will not be going back in either. I think the VIC will stay cooler without it, and with a proper heatsink installed.

Here is the board reinstalled after cleaning up the rusty bits.

The board was tested again and still worked. So next I installed a few heatsinks.

The 5 Volt Regulator doesn’t have much of a heatsink on it. The Rivet is loose and the heatsink is spinning around. So I decided to remove it and fix that as best I could. I took the heatsink off of it. I placed it on a new 2 Amp capable 5 Volt Regulator, it wasn’t needed, but that is what I keep around. I was a concerned that with the age and heat that Regulator dealt with over the years plus that loose tiny heatsink that it really should be replaced before it fails. When these regulators fail they most often fail open, meaning they will push the full voltage through them instead of dropping it or cutting off the voltage completely.. That fries the ics in the board. I have not heard of them failing inside the C64, while they are the big issue inside the C64 power supplies. With that very tiny heatsink, which was also not making good thermal connection to the regulator I didn’t want to take a chance on it. This time I put a second folded back heatsink behind it with thermal compound between the heatsinks as well as on the back of the regulator and bolted it all together.

As far as the case repairs go, I guess I didn’t take any pictures to show that specifically. The top of the case is cracked in the front right corner, it appeared to have taken a hit to that corner. It also has 2 cracks in some of the screw supports. I used my solder iron on a lower temp to melt the inside of the crack in the corner of the case together again. Then I put some liquid Testors Model glue in from the back to smooth it out. That did start to melt the plastic, I removed the excess glue. I have found that if you use that stuff and it melts the plastic and there is too much excess glue the plastic won’t harden again. The one standoff in the top of the care there is cracked as well, I haven’t fixed that yet, I think maybe from the same trauma that cracked the top. Three of the standoffs that hold the keyboard in place were sheared off as well. Those I glue back on with superglue gel. I then clamped them for a day and left it sit. That will give me the best strength, they shouldn’t be stressed while it is curing, which is 24 hours to get to full strength per the manufactures directions that is. The clamping ensures they are down properly and the joint is thin and tight too. After that I put some Bondic glue around them, the Bondic won’t cure in the crack because it needs UV Light to cure. I have also found it doesn’t bond very well compared to Super Glue. It does retain some flexibility and have some hold, I find that can assist Super Glue because it holds so tight, but doesn’t flex and fractures.

This case is badly discolored and I don’t want to try to retrobright it. I picked up some Krylon Fusion All-In-One Paint+Primer “Matte River Rock” paint awhile back to potentially paint a 1541 case. The case had some small chips out of the bottom. I took some Tamiya Putty “white” and filled in and built up the missing areas. It is a potent thin putty that dries quickly, and sands well for me. I it seems to bond to the case plastic well (As the model glue fuses the plastic, so I would expect the model putty to grip it well too). When I was done with the physical repairs to the bottom portion of the case, I put a even coat of the Matte River Rock paint on it. It turned out well. After the paint dried I found a crack show in the center of the half circle of the video port in the middle of the case. I glued that with the Testors Liquid model glue, I hope it holds well. Later I will put on some epoxy to help give that crack a little more support (I should have used Epoxy on the keyboard plungers instead) . I think once the board is reinstalled it will have more support where that crack is as well.

I haven’t done anything to the top of the case so far except weld and glue the one crack. The one case clip on it is broken off and lost. There are also 2 screws posts in the top that are cracked. I have thought about getting one of Birt’s “Hey Birt!” case saver kits to get a new case clip, I could use one of the reinforcement pieces on the cracked stand off, and have spares for the future. As I have to fix that case clip, I don’t want to paint the case yet, I will likely scratch up the paint having it upside down for those repairs. I will put several coats on the case. I want to test the paint on something with a Matt Finish clear over it. Some paints don’t mix well, and can cause the lower paint to lift or got to a crackle like finish. I have found that even with paints from the same company.. So I will test the Krylon Matt Finish first on a scrap of similar plastic (probably a modern computer case bezel). I want to put the clear over it, even though I like the existing Matt Finish of the paint as it should help protect it better.

So for now that is about it for this C64. In the future I will be doing more to it. The remaining repairs to the case. That include the Clip and post repair as well as painting and installing a new Badge plate. Checking out the * key, as well as installing the replacement keys and springs. I also have a capacitor replacement kit for it. With the 84 Breadbin I already worked on, I had found some capacitors that showed evidence of failing, so I figure this one is going to be served well by replacing them. I do wonder if that, especially the ones in the RF Modulator, may make a difference in the video output. I may or may not install some additional heatsinks. The computer is working fine, but it does have bad jailbars, so I may do something with that too at some point. I don’t know of removing the modulator and building up a replacement would help that or not.

I would love to know where the other Breadbins that were sold with this ended up and see that they were properly cared for. There was a very interesting VIC that I would have loved to see, but I wasn’t paying that kind of cash for a VIC let alone one that looked like it spend a few years sitting in water.

Pi1541 in 1541 Case & Tapuino – Part 2 (Board Etching and Build)

Lets see what was left after the last post. There were quite a few changes to the board layout. I found several defects in the circuit diagram I had made.

There were corrections for the Pi1541 section, in that I had connected up one of the signals that I shouldn’t have. The removal of that bit made the design a bit simpler actually.

For the Tapuino side I had several missing connections. So the layout below is not the exact same layout seen below here. This one below is the corrected revision with a few additions as well.

 

Here is the design minus the Ground connections.

I built the Pi1541 section based on the Option B design, but with the additional signals wired in that were listed but not wired. That is why I have the second level shifter on the board. I sort of think of it as an Option B+ design, there are some others out there, but most are just plain Option B. It didn’t matter originally, but for some of the new features he has been working on, the additional signals are needed. The problem though was that the oAtn or OUT_ATN should not be wired up as it will never be used, so I had to remove that and I had to do some modifications to my prototype board below. I also added the Buzzer for the Pi1541 to the board design. The next changes were the missing connections to the 4052N on the Tapuino section. I was missing 4 lines going to the IC, two being ground and two to the ATMEGA pins. Some other additions are Read and Write LED Indicators to the Tapuino.

The board I etched was no the above design, to correct my prototype board, I had to cut the lines to the oAtn, removed the wire from the pin on the Pi for as well. I have added wires for the missing traces to the ATMEGA from the 4052 and grounded the other two pins. My buzzer is on the Pi header not the board, and I don’t have the additional Tapuino LEDs.

The images of the board below are the board made with the previous design. That is why it won’t look exactly the same. Some pictures show the corrections and some show how it was originally assembled.

First let us start of with the Toner Transfer process. To do a toner Transfer you need a piece of glossy paper. I initially purchased some Toner Transfer Paper, it was rather pricey for all the more use I get out of it. With Eagle I can not find how to “tile” my printout, so I am using a full sheet for any tiny board.. I found you can use magazine pages, so I tried that. It has worked out pretty well actually, although The first run didn’t. This is a more complex board, it is double sided, and it really is not easy to line it up properly. To do so, I printed out both sides. The top mirrored and the bottom not mirrored (as the bottom is printed mirrored already). I then lay them on top of one another and with light behind them I get them aligned. I then cut the sheets down. This gives me some registration of the alignment. I double and triple check alignment. I tape the two sheets together on two opposite edges with clear tape. I do not want the tape to overlap onto the circuit board material, so I had around a inch boarder around the board printout. If the tape overlaps the design it can make it not transfer properly. We need no assistance in having a failed transfer, that is easy enough to get without additional help.

That being said here is how my first try went.

My next attempt went much better.

With that transfer I just had to touch up some places with a sharpie in the ground plane areas. It was not easy to etch though. It took quite a few passes and pulling the board out as the toner ended up starting to lift in a number of areas. I don’t know if it was my toner (I think it is at least partly the aftermarket cheap toner), or the extended time it was taking in the etching solution for me. I was just using peroxide, vinegar and salt. It was taking a long time. I don’t have anything stronger here, but due to the time it took, I may try to pickup something else in the future.

Below is the completed board after etching compared to my printout samples. There is one bad short, I don’t know why it did that there. There are some areas that were a bit close. The transfer process is to put the board between the printouts, and use heat and pressure to transfer the toner from the magazine paper to the copper. The copper must be very clean and not tarnished. I sanded it with fine sandpaper, then cleaned it with some rubbing alcohol. You want “enough” heat but not too much, too much and the toner melts and deforms, to little and it doesn’t transfer. Too little pressure and it won’t transfer, it seems the more pressure the better. I use a small iron that I can put a lot of pressure on, but I don’t find it easy to do. Once the transfer is done (or you think it is), then put the board into some water. The magazine paper will break down and come off leaving the toner on the board (if it worked). Carefully wipe it off to get that white paper haze off of the surface. Then put the board into the etching solution. (I have some examples and details of the process on my Commodore Computer Saver post, which is a more recent post here.)

I was extremely happy to find out my alignment was nearly perfect. It etched well, although it took forever. This is the second board design I have etched, and only the third board. The first being an adapter board that was extremely simple. The other design I did, I had the traces closer together with less empty gap. The wider gap I had here between traces made it much easier to solder up as there is no solder mask present.

The next step was to drill all of the holes. That took awhile. It required some very small drill bits. I had picked up a set of very small bits from Harbor Freight last year for very little cost. They turned out to be perfect for the job. The only problem is it would have been forever with my pin vise drill. I went to the drill press (from Harbor Freight as well), and well it couldn’t hold bits this small. Well my pin vise drill is metal, and round if I take the bottom piece off. I carefully installed it into the drill press chuck. I tightened it just enough to hold it and left the other bit holding part inside the shaft of the pin vise to make it stronger.

I then went ahead and drilled out all of the holes. The smallest being the holes for the resistors and capacitors. The last board I did, I drilled some of the holes a bit large, that made it hard to get the leads to solder in with too much gap around them. This time I went with the closest size bit I could. That ended up being about 3 primary sizes, the smallest for the resistors and capacitors, then one for the Dip sockets and finally the pin header and other connectors. With a few larger ones for the mounting points on the PS/2 style socket and board mounting holes.

With this being a double sided board, and no plated through holes I had to pay special attention to assembly. I used Machined DIP Sockets for the ICs, as the top side of the pins can be accessed with them tight to the board, and some of the connections are only on the top of the board. I didn’t have a Machined socket for the ATMEGA, so I used machined strip headers for it taking care to make sure they were standing up strait. I did not assemble this board in the order I would if it had been a manufactured board with proper through holes. Normally I would put in the short stuff first, then the taller stuff later and the tall connectors last. I couldn’t do that, and get to the areas I needed to on the top side.

As I mentioned above there were some changes to the board after I etched it. The above image shows it as it was made initially. Below here is the revised board with the corrections. The removal of one resistor in the Pi1541 area, I also removed the one header by the Serial port due to there having been a short under it I had to remove. I didn’t need that header in there for my exact use. That header would be used if you wanted to put in a Second Serial port like the real 1541 has instead of the PS/2 type port I am using for my 7″ LCD interface. The same header coming off the PS/2 port wires to the removed header above the Serial port to enable it in that case. The cutting of one trace in the Pi1541 area by that resistor on the bottom side of the board. The additional two wires for the Tapuino between the ATMEGA and the 4052, as well as the added. Ground pins connected up to it. Again the below changes don’t need made to the “newest” design. These modifications are due to the earlier defective design I etched this prototype from. If you compare them there are quite a few changes between it and the revised design at the top of this post. This is how the board is in my drive now though. I have the Pi Buzzer for the Pi1541 directly on the GPIO of the Pi. I don’t have the Read and Write Status LEDs for the Tapuino, although I am thinking of adding them. It is worth noting that the pinout for the header that is going over to the Pi’s GPIO is different on this earlier board than the revised board. The changes were to move the Buzzer to the board, but also I swapped the positions of two of the signals to simplify the traces going to the Serial port.

Here I have the board installed into the chassis.

You may wonder about the Black Oval thing in the middle on the right, that is a Ground Loop noise isolator. It is between the Pi’s Audio Jack and the Audio Jack of the Little audio amp at the bottom of the case there. Without it, there is a buzz. I have used a couple of these things now for that kind of isolation. I believe they are essentially a transformer inside, so there is no direct electrical connection between the grounds.

I had mentioned in the last post that there was an issue with the Meanwell power supply needing a 200mA minimum load on the 12Volt rail. My solution to that problem was to install two 100mA rated fans. The one I put on by the little audio amp. The ic on it gets warm at higher volume levels, so I figured it was a good idea. The other fan I put on the top of the case by the Pi to cool it. The fans make very little noise and provide enough load to the power supply to be happy even with the Audio Amp off, which also runs on 12Volts. I don’t believe the fans are are really pulling 100mA, but they are close enough that everything is working well.

Yes the Pi1541 is working.

Here are some shots of the exterior of the Pi1541/Tapuino unit.

The Tapuino section is also working as well. Originally though, I couldn’t get the Tapuino to work with the 4052 installed. So I bypassed the 4052 with some jumpers into the IC socket and I was using it that way for awhile. The 4052 is not needed unless you want to be able to duplicate from another device into it. I put it in the design to have it “complete”. It lets you connect up either a physical Cassette and dub off of it, or another Tapuino (why?). To use it, there is the unused red header there in the Tapuino section that would go to the other device. I eventually came to the conclusion that the likely fault was the specific 4052 IC I was using. I was trying to use some 74HTC4052N ics, and they just wouldn’t work. I ended up ordering some 74HC4052N ics, and those worked perfectly. I try to be careful when ordering in ics, and the fact there are so many similar models it just doesn’t always work out. I don’t know what the difference is in the HTC that it won’t work in the place of the HC chips for this use. For the old 8bit stuff usually you use LS stuff, but these don’t come in LS. If you don’t want to duplicate tapes to the Tapuino, then you really only need to bypass the 4052 with two jumpers, you could even leave out the IC socket and jumper on the board.

I would like to post the board design in some way that it can be downloaded by others that may want to try to use it. I don’t know about making Gerber files though, I could post the Eagle files somewhere and then someone could do Gerber files themselves. Eagle is free for these small designs.