Tag: diy

Meshtastic Outdoor Solar Node

I have been testing out Meshtastic for a little while. My house is in a low spot, and in a somewhat rural area. Due to that, I can’t connect to many if any nodes from inside. This meant, I wanted to to mount a node out above the roof.

I wasn’t sure what I wanted to go with, but I really didn’t want to run power out to it. So I need a solar panel, battery, an outdoor grade antenna and the node with the Lora radio. I also wanted to go with a Temperature, Pressure and Humidity Sensor.

I decided to go with the “RAK4631-9-SM-MESH-STARTER” kit for the Meshtastic controller and radio. The RAK4630 is lower power than the ESP32 models. It is the US based 915MHz model. The kit includes everything except a power supply to make a node. Granted I am not using the supplied stubby LoRa Antenna. or smaller LoRa PCB Antenna.

This kit included both the PCB LoRa Antenna, and the stubby SMA connector and antenna. The kit was purchased from Digikey.

I went with a 5.9″, 5.9″, 3.5″ Outdoor box https://www.amazon.com/dp/B0CHHPMX7M

It came with the items seen above from the listing. I used the Mounting tabs and two black cable glands.

I went a bit overkill on the Solar Panel with a panel listed with a rating of 6Watts. https://www.amazon.com/dp/B0DHXT847P

It was very easy to work with though overall. I was able to easily mount it, and use the MicroUSB to USBC Adapter to plug into the RAK board to power and charge it.

I also added a BME280 Temperature, Pressure and Humidity Sensor Module (Note the BMP280 is only Temperature and Pressure Sensor, the board I purchased first.. Then the board shown below well it has both BME and BMP listed on it making it rather confusing.)
https://www.amazon.com/dp/B0DHPCFXCK

To round out the internals, I used a 18650 Lithium battery and battery holder. Then a few M2.5 Screws and 3d printed spacers.

Externally I also had the outdoor antenna kit. https://www.amazon.com/dp/B0F6V8XBF4

The antenna is listed 915MHz and 5.8dbi. It came with a 10Ft Low Loss KMR195 Cable and mounting bracket and ubolts. Oddly the “listing” indicates the cable as N Female to RP-SMA Male. The cable though was N Female to SMA Male. .

I mounted the Antenna on the top of my mast for my TV Antenna. Below you can see it mocked up to the antenna mast before mounting it on the house.

That made the antenna easy, short of getting high enough to mount it.

Before I did that, I had to assemble and test the Meshtastic node.

It was reasonably strait forward. I first laid out where I figured I would place everything. From there I took out the removable plate in the back of the case. I then installed the two cable glands in the bottom of the box. One is for the Antenna wire, and the other is for the Solar Panel. The Battery holder has a screw mounting hole in the center, so that was easy to install with a M2.5 screw and nut into one of the square holes. The RAK carrier PCB was just a little more complex. I only mounted it with 2 screws, but because of the components on the back of the PCB I had to use some spacers to stand it off the plate. Two screws can hold it board fine, so as the other holes didn’t line up, I decided to leave it with just those two. The BLE PCB Antenna was just stuck with the provided sticky pad on the back of it.

The battery holder had to have a JST PH 2.0mm connector added to plug into the Battery port.

The BME280 was very easy to install, as the RAK PCB has a 4 pin header that exactly matches the layout of the BME280 4 pin header. Due to that, I soldered on pins to the BME280 board and a 4 pin female socket into the RAK PCB. That makes it removable, but it is so small and light that it is very secure on the pins.

The only real work was drilling out for the SMA port for the Antenna. I placed it just below the battery, and in the photo it has the stubby antenna that came in the kit. There was not quite enough clearance behind the plate once installed, to mount the SMA Female into the plate. Due to that, I very slightly drilled into the back of the case to give a bit of clearance. Also for enough clearance, I used a spacer/washer on the back of the screw for the plate that stands the plate just a bit off the back of the box.

After installing it initially, there were few items I wanted to address. I went to address was venting the box. When the sun is on the box it was getting up to 115 Degrees F. On a sunny day the highest temps look to peek at 9am and start to drop off around 1pm where it is mounted.

I looked around at types of vents. Due to the size needed, I decided to 3d print some vents. I am not good at 3d modeling, so I looked for a model to start with. I found this model https://www.printables.com/model/77087-enclosure-vent-w80mm-fan-mount for mounting an 80mm fan. Due to the size, I was not able to keep it that large, I worked out that a 25% scale would be a good fit to be similar size to the cable glands. That space limitation and the maximum size of my step drill bits as well. I could go slightly larger, but I couldn’t reasonably drill the hole required.

The primary changes were the scale, as well as taking it to a 1 part vent design, and adding a “Grill”. The downscaling of the model made the threads not as well defined, and the threaded area depth to short. I ended up looking around to replace the threads, and found this great Cable Gland model set that includes many sizes https://www.printables.com/model/114283-cable-gland-all-sizes. I picked the D16L10 I believe or the D17L10 size. I then replaced the threaded portion of the vent. This was because I was because I was printing that threaded portion at 100% scale. I also made a simple seal washer to print in TPU.

The nut was unchanged, but for it to fit when printed on my printers, I had to print the nut at 101.5%-102%. The Vents and nuts are in PETG, with the washers being printed in TPU. I did print the seals at double thickness compared to the model, you can see the thicker seal on the left vent and the thinner seals in the background.

Above you see the node installed with the solar panel. One of the 3d printed Vents is mounted on the side of the case behind the upper clip. If you view the full size image, you may see the 3 small drain holes drilled into the bottom of the box in a line along the center. The 10′ antenna cable is basically fully used to get to the top of the antenna mast. I have mounted the box below the antenna mast because my regular 12′ ladder can just reach it to service it there. I can’t get to the antenna bracket seen just above it (safely) with any ladder I have myself let alone reach the upper mounting bracket or antennas.

I don’t know if the Venting has made much/any difference. In the morning it did hit 95degrees this morning when the sun came up and it was closer to 65-70degrees outside. It did drop off, but it was getting cloudy. It may require another vent, and a fan to make a significant change.

The solar panel works well for much of the day in the position it is in. The battery ends up still being around 85% overnight with this setup before the solar panel starts providing power in the morning. I wish the solar panel cable was easier to shorten. It is 10′ long and obviously just tied up under the cabinet at this time. I may be able to stuff it inside the box, but I expect that could get crowded.

I thought of cutting the Solar panel wire and installing a connector to connect it directly to the RAK PCB has a header for a solar panel. I didn’t have the JST ZH 1.5mm connectors or crimp tool when I built the node a few weeks ago though.

There are various changes I would like to make. The visible one being to shorten the Solar Panel wire. I have not decided what to do there yet though. I did get the JST ZH 1.5mm connectors and crimp tool. The problem there is that I am planning to swap out the RAK unit for for a Pico based solution. The RAK works great, it is very low power, the battery keeps up fine overnight, and should keep up just fine in the winter as well. The RAK is only Bluetooth though, I am wanting to look into a Wifi based connection to it as that seems like it will give me some more options to interface with the node.

The node does get a direct connection to several other nodes now that it is mounted outside. The low node count is partly due to my low location and partly that there aren’t many nodes around. In the last few months there have been quite a few well placed nodes installed in the valley by someone though that have created increased coverage. I don’t believe my node is important to the mesh with those being out there. It is in Client mode though, and I do use it most often, as my other nodes much reach out to it to get signal to other nodes anyways. They are all in Client Mute mode due to that.

Pico 2 DRAM Tester

Lee of More Fun Making it on Youtube made a video building and testing the Pico-dram-tester. I like building up these types of projects, especially when the device is useful. I believe Lee mentioned he would like a power jack, as the intended power method was using test points. It can be powered by the Pico2’s USB port, but that wasn’t recommended, also such ports are easily damaged, and it would make it so you couldn’t update the device etc.

Original Github Project: https://github.com/schlae/pico-dram-tester

Lee’s Video: https://www.youtube.com/watch?v=7orsBI78VHI&t=799s

Lately when I have been ordering PCB designs by other people, I have found there were little changes I would have preferred to have made before ordering them. So I decided this time I would take the time to make some of those changes. I just didn’t want to use Test Points for powering it. I modified the design to include a DC Barrel Jack, center Positive 5Volts. The other primary change was I wanted to make it easier to “bodge” in the more common generic Rotary Encoders that I have. I didn’t know for sure if the generic Rotary Encoder would work, so I didn’t do anything too fancy in the first pass. I also made other minor routing changes throughout.

Because I picked White for the PCB, the tracks are very hard to see on photos. Somehow I put the wrong month reference on the board silk screen. I guess I should have labeled it as Revision 2.1. It was based on the Revision 2 with those minor changes. I did remove 1 Ground Test Point footprint, both were wired identically. There was no point in keeping it, and I didn’t have room for it.

The build went fairly strait forward. The primary recommendation is to put the Pico 2 on first. Don’t be confused by the project name “pico-dram-tester”, it doesn’t use a “Pico” it uses a “Pico2”. I put on the Resistors on next, then the 100nF Capacitors and then the taller components. I did use the Adafruit LCD so U9 was not required.

I did have to cut a trace at the Rotary Encoder, and put in a single bodge wire connection to ground. The common Generic Rotary Encoder lower center pin needs to be grounded, where the specified Panasonic Rotary Encoder that pin is a second “B” directional pin. (Note: “my” Rev 2.2 variant doesn’t need this done)

Rotary Encoder dodge on Rev 2.1

Once it was finished, I used it to test some 4116 chips and 4164s. It failed all of the bad 4116 chips I had, and passed the good ones, as well as the 4164s all passed. I found the 4164s pass to their speed specification and did fail if I set the tester to test for higher speeds.

The 4116 chips verified the -5 and +12 is working as well. I don’t have any of the other types of DRAM ICs to test.

With it working with the Generic Rotary Encoder, I just had a few finishing touches on this built. I needed a knob that fit the D shaped encoder. I found a knob that fit nicely.

https://www.printables.com/model/347536-encoder-knob

I also wanted a case, a full case isn’t very practical. I did find a Tray/holder case for it.

https://www.printables.com/model/1248424-pico-dram-tester-case

The case didn’t require any changes to accept the DC Power Jack because there were already all of the Test Points there. The DC Power Jack does hang off the edge, which was intended, due to lack of space and I wanted it to be flush with any case it may be put in, rather than deep inside the case.

I did also print some spacers and install some M2.5 screws in the LCD PCB to keep it supported and solid. I put a bit of Red paint on the 4116 IC Socket. I also swapped out the button cap I had on the Back button.

Finally I put some stick on feet on the bottom.

While this little build is done, there were some things I wanted to change on the PCB after putting it together. I went back and reworked the PCB for Revision 2.2.

The new changes primary include a set of solder pad jumpers to configure the Encoder to either use the Panasonic Encoder, or the common Generic Encoder. The other changes are mostly Silkscreen changes. I prefer when the Component Values are on the Silkscreen as well as the part designations. There were some other minor routing changes, changes to via placement and such. I have uploaded Revision 2.2 to Github: https://github.com/Markeno76/pico-dram-tester

Below you can see renders of Revision 2.2 The solder pads can be seen to the left of the encoder footprint, instructions for JP1 are on the back of the board. Component Values have been added, also the Back button now has the “Back” text displayed.

I did find there is another fork of the project, that includes changes to the firmware. I want to look into that, as there are changes to work better with the Generic Encoder such as I have used. It works fine, but I believe you will get less “bouncing” with the alternate firmware. I do plan to look into trying that firmware, and see if I can bring it into my fork.

Update: 9/1/25: The original project has had the firmware updated several times since I built this and posted my revised pcb design. Now supports 4108 and 4132s the half good/bad chips used in some 8bit computers back in the day. I just found out about the firmware update watching another of Lee’s videos last night. I have merged in the updates into my fork, but those are current as of 9/1/25 so check the original github project for future updates.

Apple II Analog Gamepad

I always like to having the option to use a game controller for my computers. I only like joysticks for certain types of games. I prefer gamepads for a lot of game types. The Apple II Joystick is an analog joystick, much like the IBM Analog Joysticks. I was not interested in tracking down a vintage joystick. I also again often prefer a gamepad form factor, and I like making things myself. I came across Swetland’s Apple II Gamepad project on Github. The project has good documentation for the rather simple project it is. I will just go over any variations or considerations I had with it.

The project worked like many projects I tend to do. Some little oddities in that it has not went through very many revisions. This project is fine, and can be built as is. If I had read the provided information before ordering the PCBs in, I would have probably implemented some of his suggested revisions.

The simple revisions that could be done.
Swetland indicated making a switch to swap the button positions. I think this may very well have to do with him testing it with Lode Runner, which is the game I tested with. The buttons should be swapped for that game in perticular.

It was also indicated to potentially use the joystick’s button. I hate that on the Nintendo Switch though in some games.. I like having options though. I think the Apple II can address 4 buttons? I only think that as there is a PEEK for 4 buttons, and I don’t know how often that there were 4 on a joystick or if any games use them all.

It also was indicated that the range may be adjusted by adjusting the capacitance. To add more, it would be easy to just add some pads to add another capacitor or two.

My thoughts might be to increase the footprint size for the capacitors and resistors by one SMD size. It may just make more people consider building one, as I feel many people either have limited SMD experience or may just not be able to do it. It does take magnification for me, and my hands are pretty steady. It wasn’t bad for me, but I have a bit of experience with SMD soldering now. It would also be easy to add alternate through hole footprints for the resistors and capacitors. I had the required resistors and capacitors in stock (one size larger than specified I think though on the capacitors, they just could fit.), but I also have the parts in typical through hole type of the same values. SMD parts are cheaper, and take up less space, though space in this project itself is not an issue.

If I were to go to that trouble, I would also upsize the traces to make them more robust, that may also open up some options for customization and bodges for those old hacker types out there if someone comes up with something. The other thing I would probably do is look to put the wires on the pcb in the same order as they are on the DE/DB9 connector in hopes to reduce the chances of making mistakes. I might put some instructions and such on the silkscreen. If I find these other 4 unused PCBs in 10 years, I won’t know what the component values are etc to finish assembly and there is plenty of space to put the required basic information on the board itself.

I would also look into building in an optional auto fire circuit directly into the pcb design.

There is an oddity (at least to me) with the threaded inserts. The holes are basically 5mm in diameter. My threaded inserts are 5mm in diameter, which are designed for 4.5mm holes. As they were to small, I then went and ordered some that said they were 5mm, and they turned out to be identical to the ones I have. So you need some rather large M3 inserts. I happened to have a single giant M3 insert that I don’t know where it was from, and I used it, I then added some glue to the remaining ones and used the 5mm diameter ones. So another revision I would make myself is sliming down the holes in the 3d model.

None of the issues I had were a any kind of big issue. It is just the kind of little things I think would be easy to refine on the project. If I had noticed the suggestions, I would likely have taken time to make those changes to the PCB design. I am just not one to throw away the PCBs after ordering them because they could be just a bit better. Now that I have 5 of these PCBs, I have no drive to do the revisions myself.


Below you can see the threaded inserts installed in the case, the one to the left of the cable there is that single large diameter m3 insert I had, the black around the other two is a bit of the glue. The case printed flawlessly in a nice color change PETG that I like, and also in a filament I am nearly out of, so the little bit of glue is fine. If I ever assemble another of the PCBs, I will do that minor change to the case so the inserts I have fit it.



I didn’t look at the DB9/DE9 port on my IIGS recently, or read the specifications before building the joystick. I then proceeded to buy a molded DE9 Female cable for the gamepad and installing, which the Atari 2600, 800XL, Commodore 64/128 etc all used. So I have some nice photos of the Gamepad with a nice molded DE9 Female connector. I then quickly removed that really nice cable and attached a black piece of Cat5e stranded patch cable and a solder on DE9 Male connector and shell. I didn’t have any tapered m3 screws, so I used some button head screws.

Opps wrong cable.

The hole for the cable was just a little larger diameter than my cable, so I quickly made a gromet/strain relief sleeve in Tinkercad and printed it in TPU. That sleeve is just slid on, it is fairly snug, but can be moved, if I wanted to permanently attach it, a bit of thin superglue would fuse it to the cable jacket. Then for the Shell, the cable was to thin for the Clamp to grip the cable. If I had noticed that sooner, I would have slid on a couple layers of heat shrink tubing. As it was, I already had it all soldered up so I wrapped it with some glue backed Heatshrink and heated it to shrink it tight and fuse the glue. For the DB/DE9 Shell (and the reason I wanted a molded cable), the front holding lip that goes over the metal of the DB/DE9 connector needs to be shaved down to the minimum so that it inserts deeply enough into the IIGS Joystick port. This is the same issue that I had with the RGB Monitor cable shell. The casing around the ports is just too close, it is kind of annoying that Apple did that, I can’t think of a DB/DE Shell design that I have come across that will fit nicely without modification.

It was a very nice clean easy build. I wish it had the nice molded cable, which would have also made it an even quicker build. If you look at the Github project, you may notice I used different buttons. I did not use the ones with the square cap posts. They are the same height and footprint minus the little posts. I actually have both types. The difference is the button tops (which I printed in TPU) are not snapped/locked to the buttons, but they sit just on top, there is no extra space so they are not flopping around. I felt this may be less likely to make the buttons bind, that is not to say they actually would have bound up at all.

That other cable did not go to waste, it prompted me to finish another Gamepad project that has been sitting to the side for a few years. That other Gamepad was actually finished before this one, as I had no DB/DE9 male connectors left and had to wait for them to arrive.

It was a bit odd I used Lode Runner to test the Gamepad as well. It is not a game I have really played much at all, it is one I have seen and I am familiar with though and figured it would work with a joystick. It was somewhat frustrating having the buttons in the wrong order as the right one digs to your left and the left digs to your right. The cap keeps popping off the joystick, which is not the Gamepad design’s fault. I did turn both adjustment pots all the way to the left (counter clockwise) so I would get the full use of the joystick, it was staying pegged at 255 when centered on both axis with the pots centered. It feels good to hold and works well.

I’ll figure something out on the Joystick cap issue, and I look forward to using this to help me explore some of the many game possibilities in the IIGS. I have a second one of those types of joysticks, but I believe the stem design on the joystick is a bit different.

Pi400 in a Case

Initially when I saw the pi400 come out several years ago, I was really looking forward to it. That was until I purchased one and started using it. It was lacking in several areas. It is nice in that it is compact. With it being so compact and light, and having to having a number of small cables connected, I found it messy and was concerned with it sliding around with use that may cause either the power or hdmi etc to come loose while using it. I ended up building my AMpi4 to tick all the boxes on changes I wanted for it. This left me with some pi400s in my stash with nothing to use them for.

I’ve liked the CyberDeck ideas. I like aluminum hardcase briefcases. My goal is to make this a fully portable self contained Pi400. I looked around for the largest reasonable display to use. I then looked around and found a touch pad to include. I then looked around at possible cases to use that I should be able to fit the equipment into. I also looked at options for a battery to power everything. The LCD runs at 12V, and is 13.3″ with a 1366×768 resolution, the resolution will be a problem later though. The battery is a 12V 5200mAh pack rated to be at 9V when drained, and 12.6V fully charged. The case is a 15″/10″/4″ case, this turned out with my choice of setup to be just about the minimum size case due to depth. My primary focus initially was to work out if and how I could fit everything into the case. I wanted the pi400 keyboard about flush with the lower thicker portion of the case, and then the LCD bezel had to sit just below flush in the top so they didn’t hit one another.

So the primary parts are above, the case, the battery, the touch pad, the 13.3″ LCD and the Pi400. There are many more components, but these were the first past to start to verify I could fit them in the case properly.

The case it a bit large, so I can’t print the panels in one piece. I did work out that I could do a 300mm wide that would hold the Pi400 portion fine, which is about the max of my S8 3d printer can handle. I found a 3d model of the Pi400 listed as intended to make cases etc, then modeled the touchpad. I did a test print, it worked for fitting, but neither the Pi400 or the touchpad fit properly.

First Fit
Wall
Feet
Protopanel

The various other items I have been working on fitting in include some power switches, volt meters and leds. I also worked in a .96″ I2c LCD and RJ45 keystone jack into the lower panel. I recessed the control panel on the right so it would have clearance to the top.
The switches are for the main power switch at the top, then 5Volt supply in the middle and the 12V supply on the lowest switch. Each switch has an LED to show it is on. The various status LEDs are wired up with 2.7k resistors. The volt meters are for the 5V and 12V supplies, there is a difference with mounting them. I had to use “smaller” threaded inserts and screws, they are salvaged M2.5 Inserts from broken Laptop cases. The 4mm Diameter M3 inserts were too large there to line up with the screw holes in the volt meter pcbs. There is a vented wall connecting the two panels together, and feet that contour to the case to keep the panel at the proper depth. The holes on either side of the touchpad will be speaker grills, as I am relocating the speakers from the back panel of the LCD case.

The LCD needed a nice way to mount as well as to be thinned down. I just didn’t have the clearance the keep the original case back for the case. The Speakers needed to be relocated, and the best place for that was down in the main case by the touchpad, to do that I made up an extension cable for the speaker wires. They really should be run with a shielded cable, unfortunately I didn’t have a 4 wire shielded cable to use, this does have a bit of a noise out of the speakers from interference. I may swap the wire out for a shielded cable once I come up with one. I also had the relocate the buttons, as they were on the back of the LCD case, and needed to be accessible. The Power/Status LEDs for the LCD are very small SMD parts, and were not practical to relocate, and the IR Receiver is on back of the button board as well. I was going to relocate the IR Receiver, but I have nice slot vents around the LCD and the IR Remote still works with it on the back of the Button PCB. Removing the back of the LCD case let me keep the Bezel and use the old mount points to connect it to the new upper panel. I did have to make some standoffs and find some longer screws to mount the bezel with due to the standoffs. The Button pcb is using the original screws. The LCD Controller pcb had been mounted to the back case, so I had to design up a mounting plate for it.

The other portions I added to the top panel were an RCA port for Composite Video input, and a 3.5mm Audio input jack. That did not work out, but some pictures here show that layout. I wired the 3.5mm into the audio in on the monitor, but that doesn’t connect when in Composite Video selected, I think it is for the VGA in. The audio doesn’t play if there is no Video signal either. I later changed the setup there. I also have added an Adafruit RFM95W LoRa Radio to setup Meshtastic on the pi400. For that I also added a power switch and status LED for the LoRa radio. The radio runs on 3.3-5V, with 3.3V IO, I am powering it from 5V. The Antenna mount is also in the panel, and fitted so it can stay attached when the case is closed, with it to the right of the toggle switches. The top panel also has a 4Port USB 3 hub, when installed it bottoms out back to the case top for support, and the usb cable just comes down through an opening into another opening in the lower panel, the primary issue is things are quite tight and I needed to use a 90 degree extension as there wasn’t enough clearance for the regular usb connector. The USB Hub is not actually secured very well. I did reuse some of the cloth tape from the LCD Monitor’s case that held the wires in place. I was going to use zip ties to grip around it, but there is no clearance, I was going to make a 3d printed band or strap and use threaded inserts in the front panel around it to grip it, but no clearance for that either. It could be taped in tighter, it could be glued in, even possibly using the holes I made for threaded inserts for points for the glue be it hot glue or epoxy or other glue if it turns out to be too loose. I left in a square hole to the right for the LoRa wiring, speakers, 12V Power for the LCD and potentially the HDMI connection for the monitor. I put that wiring all through a wire loom bit that I salvaged. I went with a HDMI Ribbon cable, so there is a small slot (larger than required) that lets the ribbon come down from the top panel into the lower panel.

Speaker Extension
Yes the Speakers are unplugged yet.
LCD Standoffs

The second print of the panel for the pi400 and Touchpad fits mostly. The pi400 is still too tight, which is why it looks a bit “popped out” in the picture above. I reworked the speaker grills, which I like better than the square ones that I had before. In the photo the battery is external as I haven’t worked out the internal mounting for it. This second print of the panel was printed face down, where the first prototype was printed face up.

Fixing the Resolution: You may not see but in the photo above the image is going off the edges of the LCD, you have to use a custom resolution 1360×768 to prevent the image going off the edge of the display.

To use the custom display, you have to edit the “/boot/firmware/cmdline.txt” At the end of the line add ” video=HDMI-A-1:1360×768″ or ” video=HDMI-A-2:1360×768″ depending which HDMI Port you have attached the monitor to. Save the file and reboot, you should see the screens on startup have changed to the new resolution. When you get into the GUI, the resolution will change back to what it was set to previously. Go to the menu, and find “Screen Configuration” under the Preferences menu. You should now see 1360×768 as a selectable resolution and be able to change to it. Then the overscan works properly and image is no longer going off the edges of the screen.

To power the pi400 and LoRa radio, as well as anything else 5V, I am using a 12/24V to 5V step down regulator unit that I have had for awhile and it is kept in place with Velcro so I can easily enough remove it. I ended up not using it for another project. It seems to give just a bit over 5V, which is what the pi400 likes. I have run it for quite a few hours without any issues. I made up a USB C power only cable to connect it up. The 13.3″ LCD power goes to a 5.5mm barrel power jack to make it easy to remove. The LoRa radio is mounted with some double sided mounting tape, which I put some Kapton Tape on the bottom of the LoRa radio board before putting the mounting tape on it, as I wanted to make sure I could get it off without damaging the board if I ever need to.

The USB Touchpad needed the cable modified. It was a bit too high up on the side of the case, and extra long. I ended up removing the cable and installing a shorter usb cable. It is a heavier cable, being shielded, but it was just about the perfect length. It also had a short usb connector so it has clearance to plug into the Pi400 USB 2 port without right angle adapter.

I do wish the touch pad had a middle button, as it is handy. Still I can use a mouse instead either by Bluetooth or USB. I am using Bluetooth Mouse with the PiCase, but the Touchpad does work well. While I don’t like Touchpads very much, but I included it because it makes for a complete and usable device without additional bits of hardware.

Above you can see the bottom panel and a closer view of the control panel when they were nearly complete. I did swap the wiring for the Voltmeters, as I wanted the 12V at the top and the 5V at the bottom meter. I also rewired the “charging” jack wiring when I was doing some other changes later. The charging port was rewired so that the current sensor can now monitor when the charger is connected and charging the battery. You can see the Speakers are hot glued in, they were originally glued into the LCD Back case. I had made it with M3 inserts around the speakers, but I didn’t feel like making frames for them. The Speaker mount area is larger than the speakers as I have some very similar larger diameter speakers I wanted to allow for, still in the end the original ones work very well. You may notice 4 more M3 inserts along the bottom edge of the pi400 opening. I had added those expecting that the panel may flex, but for now it seems rigid and doesn’t need supports added below. I will use two of those four inserts to mount the battery holder. Due to the fit of the Pi400 in the main lower panel, I did print revised panel to replace it. On that third main lower panel, I only installed the 2 threaded inserts that the Battery Holder is attached with, the speakers are again attached as seen here with hot glue. You can also see the various “feet” around the panels. I am still debating gluing at least some of the feet into the case so the panels can’t slip out. All of the feet have M3 inserts in them and are screwed in through the panels, 1 has a screw into it through the wall that connects the two levels.

The panels fit well into the case, I still have some things I am working on with the panels, so I will not be gluing any feet into the case at this time. Right now it is just regular Raspbian OS 12 Bookworm. I have connected in the .96″ LCD and set it up for a status screen. I have also wired in and setup the LoRa radio for Meshtastic with limited success. I’m looking to add a Realtime Clock module, and also a Current module and battery status widget. I had some ideas on a GPS module and maybe an RFID module. I will make another post going over the LoRa Radio, the 3.5mm headphone jack, the .96″ LCD, the Battery mount, and battery status and RTC module and some other things to finalize. When I get finished up, I also plan to post the 3d model files for the case parts. I am still making various mostly small alterations. The last main thing should be working out the Battery mount.

I am not certain, but there is a good possibility that a Pi500 would fit this build, also possibly the official Raspberry Pi Keyboard that is largely the same case design and using an more traditional Pi of your choice or another small SBC. There is plenty of room under the Pi400 for a different choice of battery pack. The power draw of the setup varies around 0.900A to 1.25A. I fully expect that under heavier load it will go up, it is on the low end with a MicroSD card, and then with a USB3 attached SSD it is in the 1.25A range, the LoRa radio does put more load on as well when it is in use. Using a Pi5/500 may be best making a different battery and regulator choice. I would get a Pi500, or stick in my Pi5, except this build is to “use up” a spare Pi400. I really don’t like the Pi400/Pi500 as a stand alone design, so I don’t want to invest in a Pi500 at this time, or rework the power setup. I might see about getting a Pi Keyboard at some point if I am placing an order for other parts and test fit it though, but isn’t happening in the near future though. I really don’t expect to see anyone else build one of these units based on my build and models, although that would be cool to see.

Primary Parts:

Pi400
https://www.adafruit.com/product/4795

Aluminum Hard Case 15x10x4in
https://www.amazon.com/dp/B0CKMX362L

13.3in 1366×768 LCD
https://www.amazon.com/dp/B087RC8B79

USB Touchpad
https://www.amazon.com/dp/B09X2MZL3C

12V 5200mAh Lithium ion Battery Pack
https://www.amazon.com/dp/B0D9D8ZSV9

4port USB 3.0 Hub
https://www.amazon.com/dp/B0CD1BHXPZ

USB 3.0 Right Angle Extension (For USB Hub due space limitations, and likely for a USB 3 SSD adapter)
https://www.amazon.com/dp/B07F7Y21GW

Voltmeters .36″
https://www.amazon.com/dp/B0BF9FLX6H

Micro HDMI Male to HDMI Male FPC Flat Cable
https://www.amazon.com/dp/B0177ERQ08

5.5mm x 2.1mm DC Power Jack (and Plugs)
https://www.amazon.com/dp/B078YP4CP6

2 Position DPDT Mini Toggle Switch (4)
https://www.amazon.com/dp/B07QGBW6XZ

3MM LED Holders (4)
https://www.amazon.com/dp/B07WSM4V9B

M3 4x5mm Brass Inserts
https://www.amazon.com/dp/B0DG59PW2R

12/24V to 5V Converter
https://www.amazon.com/VOLRANTISE-Converter-Voltage-Regulator-Transformer/dp/B09WZ5WH8H?th=1

.96in OLED 128×64 I2C LCD
https://www.amazon.com/dp/B09JWLDK9F

JST SH 1.0mm 4 Pin Male Connector (I2C Grove Connector)
https://www.amazon.com/dp/B0CF15P6PL

GPIO Header Connection Port Breakout
https://www.amazon.com/dp/B09BF7YYBK

Adafruit RFM95W LoRa Radio Transceiver Breakout 915MHz
https://www.adafruit.com/product/3072

IPEX SMD Antenna Mount
https://www.amazon.com/dp/B0CB6D28R5

915MHz Lora Antenna 5dBi
https://www.amazon.com/dp/B0D47HVCK7

See Part 2 here: https://hobbytronics.home.blog/2025/04/18/pi400-in-a-case-part-2/

Apple IIGS RGB Monitor & SCART Cable

In a prior post I mentioned I have the Apple II RGB Monitor cleaned up and I needed to make a cable for it. Since I was making a cable, I decided to make a RGB to SCART Cable. This will go with the GBS Control devices and let me use modern displays. I had an old piece of cable used for a VGA cable originally that I thought would be a good use. I had a SCART Connector that in my spare parts that I had ordered awhile ago. I just needed the 15 Pin DE15 Male connectors.

I based the SCART Cable on https://roger.geek.nz/apple2/scart.html

Based on the source post at VintageWare, I need to wire the Red (2), Green (5), Blue (9), Sync (3), Audio (11) and three Ground pins (1, 6, 13) from the DE15 to the proper Pins of the SCART connector. It also requires using the 12V pin (8) wired two two other pins on the SCART connector via some resistors. The 12V should be wired by a 1k Resistor to Pin8 on SCART to select AV Mode. The 12V should be wired to by a 270 Ohm Resistor to Pin 16 on the SCART Connector to set the SCART input to RGB Mode. I am not using this cable on a true SCART TV, so those two pins should not have any impact for me, but I might as well make it to the proper specification.


This SCART cable was nothing but trouble due to the wire I have used. Everything just kept going wrong with it. The cable has Coax lines in it for the video etc, which is great, but very problematic to work with, this may not be as common an issue, but I am expect working with multi pair coax will commonly have at least some of these difficulties. The core wires for the signals kept breaking off at the solder point. The cable is overly thick making it not flex easily, and break them more. The DE15 connector Pins push inward out of the plastic housings (which I have never seen before, but may be common on cheap connectors..). The IIGS has thick plastic around the ports, and the Shells for the DE15s don’t fit, they don’t let the connector go in far enough to make a connection. That is common on Commodore 64 Joystick ports as well (although that is a metal surround). It was very frustrating. When testing, I just removed the Shell from the DE15, it went it great, except some pins started to push out, then when I removed it more of the coax signal wires broke off. When testing it before trying to take it out, I didn’t have the blue signal. I figured another broken coax signal wire. On inspecting I couldn’t find an issue, well visually inspecting, although the sync wire had broken off by then it couldn’t have been broken before unplugging it..

Next I repaired the DE15 end, cut down the Shell “lip” that holds it on as much as I could. I pulled all the extra DE15 pins out. I used Liquid Electrical Tape to insulate, and basically “glue” the pins into the connector and keep the coax signal wires from flexing and breaking. I also used the Liquid Electrical Tape on the SCART Connector. Then I let that fully cure. I reassembled the connectors and tested again. I again didn’t have Blue, only Green and Red. I further shaved down the Shell lip, thinking maybe it just wasn’t making contact. That made no difference, still no blue. I tried the old SCART to HDMI adapter box, and I got no video output from it. I decided I would make the cable for the RGB Monitor by cutting the cable in half and installing DE15 connectors on both making it into two cables. This cable was awful the worst I ever made. I took a week or so away from it as I didn’t want to mess with that cable again.

The cable would have been a little neater, but I didn’t initially intend to use the 12V line so I had to solder on that blue wire to the stub of one of the remaining wires. The various wires kept breaking off at the solder points and I kept adding in little bits to extend and try to get tension off of them. I am not happy with this cable. Hopefully as I went on further below I will get this working and it will be a solid cable after all the trouble and fixes listed lower in this post.

Above you can see the Liquid Electrical Tape applied to the connector. I put it all over the pins to the base. I has a good bond to the pins and case, this has locked the pins in so they don’t push out. It also holds the thin coax cores giving them support preventing them from breaking off easily.

Moving on to the RGB Monitor Cable

I decided to start fresh with the RGB Monitor Cable, I wasn’t interested in working with the other SCART cable again. I had a piece of shielded cable that isn’t individual coax for the signal wires that I decided to use for this cable. It is much smaller and flexible. I again pulled all unneeded pins from the connectors (partly as they like to fall out of these, but also as I needed them for another connector for the IIGS). This cable took nearly no time at all to make. It was easy to work with, had the exact wires in it that I needed. I even soldered the shield to both DE15 housings without any issue. I did take the modified DE15 Case Shell from the SCART cable. This cable took nearly no time at all to make, it was refreshing and was a joy to put together compared to the SCART cable.

For this basic strait through cable, I used pins 1, 2, 3, 5, 6, 9, and 13 as well as soldering the Shell to the Shield wire. This is a lot easier than the SCART, as I don’t need the Audio, the 12V, any resistors, the Grounds are just “strait through”. With the SCART most of the grounds were tied together, which is just more work in itself. I usually only wire the Shield wire to one end Shell or the other to prevent ground loops. In this case, the specification was to wire the Shell to ground, so I figured I would do it.

Only the required Pins
Modified Shell

This cable I did not put on the Liquid Electrical Tape, as I had with the Scart Cable. Nothing here is binding, pulling etc, there isn’t excess loose bare wire, the Shield Ground is soldered directly above one of the Ground Pins and can’t reach the R, G, B or Sync pins easily unless it breaks off. I did not have issues with the pins pushing out yet, I think it helps that so many pins are “removed”, creating less friction, less chance of minor miss alignments etc. Granted I did go back and remove the unused pins in the Scart cable as well. The pins were repurposed for the wDrive DE19 to IDC20 adapter in another post.

I connected up the monitor and it worked great the first time. Well I didn’t have the right colors initially as the cable fell partly out of the back of the IIGS. I pushed it back in and everything worked properly. I then used the screws to screw it in. I didn’t have to modify the shell on the monitor end, it has enough clearance for the shell.

I do think this monitor has been used a fair bit, it is clear and bright enough though. It looks better in person than in pictures. I noticed a crack the lower left front corner of the case just above the Apple Logo.

Back to the SCART Cable

On getting the RGB Monitor cable working, I looked at the SCART Cable again. Not that I wanted to after all the problems with it, but I had it apart after taking the DE15 Shell off. I checked for loose or broken wires, although everything is covered in Liquid Electrical tape making that difficult. I didn’t see anything. I then started checking continuity. I was checking all of the ground wires, checking that I didn’t solder wires to the wrong pins. On checking the ground wires, I found the Blue signal wire was shorted to ground. I had checked that pins went where they should and that the Blue pins were connected, what I had failed to check the first time was if it was shorted to another pin such as Ground.. That will cause the Blue to not work. I inspected the DE15 end and it didn’t look like anything was wrong there. I carefully removed the liquid electrical tape from the Blue signal and the Ground pin beside it on the SCART end. I found the blue somehow jammed itself into the ground. Initially I thought the blue signal wire in the coax had broken, but somehow the blue was pulling into the shield ground around it. I hate that cable. I got it worked loose, and covered it in liquid electrical tape again. Then I let that cure, checked for shorts again and reassembled it. This SCART cable is wired differently than the ones I have made in the past. I have added the resistors and used the 12V power to Pins 8 and 16. That won’t matter to the GBS Control, as those pins don’t do anything on it, but I do wonder if it will make the SCART to HDMI act differently, or if it will make the SCART work on the Sony LCD TV which I have never been able to get to take any input. I figured I had the wire for it, (and I did do pin 16 in the other cables, but not pin 8) and it was easy enough to wire up. I then tested it on the GBS Control and the SCART Cable is now working properly. I then tried it on the SCART to HDMI Adapter box, and it worked on that as well. There was some “noise” in the display, but I think I had seen that is actually there on the IIGS and masked on the CRT Monitor.

I plan to likely use the IIGS with the SCART cable to the GBS Control more than anything. The Apple RGB Monitor has certainly seen better days, and if I use the IIGS very heavily I will probably not use the monitor with it. I actually didn’t intend to get the IIGS, and I don’t currently have room to setup yet another computer. I could put the G3 iMac away somewhere, as all I have for it is Oregon Trail..

Apple II wDrive and DE19 to IDC20 Adapter

I’m really not too sure about the Apple II projects out there. I wasn’t looking to get into the Apple II, I just came across the IIGS and well I wasn’t ready for it. I always liked the IIGS from school, in Jr High I had spent time writing programs in basic on one in my Science class during study hall. They were old at that time, but I didn’t have a computer at home yet and always liked computers. We had used Oregon Trail, Number Munchers, Logo and other programs up from first grade on various models of Apple II computers in school.

The IIGS came with just three 5.25″ floppy disks. Two of them worked, but the other has errors and won’t load the program fully. I looked into the Apple II storage options. Nothing I have for any of the other computers works on the Apple II. There is a paid firmware for the GoTek that can work in combination with special adapter cables, but that looks to be rather limited in what it can do. Doing some looking around, I don’t know what the best option is. There are a number of devices. The Floppy EMU was one I looked at, but shipping and cost are up there. I found the wDrive and that was in stock and cheaper, and seems to be comparable for the Apple IIGS even though the Floppy EMU can work on early Macs (I have no early Macs and I don’t at this time plan to get any). https://ct6502.org/product/wdrive/

Some things I didn’t like about the wDrive are, that while it looks to be one of the go to devices, it does not appear to be in active development any longer. I would also like to see more documentation on it. It took me awhile to figure out why it wasn’t showing me the menus on the IIGS on startup (you need to copy the wdmain.dat in the SD Card from the firmware download). Either device though, or any of the devices I found weren’t exactly in the budget that I wanted to just jump in and purchase on a whim. Many of the other 80s era computers have pretty decent cheap data storage options these days, I was disappointed to not find something similar with the Apple II. I think it may be a bit complex though, and the IIGS is a 16bit computer as well. Update: there seems to be more new projects that started coming out around the time I was looking for solutions. So there are certainly more solutions out there than the two primary ones I had found at the time.

My limited experience and time looking at devices for the Apple II computers means, I may or may not, have made the best choice. I think the FloppyEMU has various settings that are changed per the file type, or usage you want to do, with the wDrive it just takes the files and emulates what it needs if it can use the file type. That may be a plus if I am understanding the usage, in that it is simple. The wDrive won on price being $79 vs $118 for the Floppy Emu + the case. If I had chosen the Floppy Emu I would have went with the Deluxe bundle at $129 which includes the Floppy Emu + the case and a DB19 to IDC20 adapter similar to what I had to build myself that I cover below. It was measurably cheaper, but still not super low budget. I did still need a compatible DB19 to IDC20 adapter, but that wasn’t an additional $40.


Connecting the wDrive to the IIGS:


I mentioned above that the wDrive requires a DE19 to IDC20 adapter when used with the IIGS. It is a bit problematic that the store doesn’t carry them. They do have a link to two compatible adapters, but then you have more shipping yet (the FloppyEmu store is one of the sites.). This lead me to looking for another source, and specifications on these adapters. The information on exactly what is needed is not clear. Sure we see the two connnectors… we can find pinouts of the ports. I was quite concerned I would get the wrong adapter, and it wouldn’t work, or would damage the wDrive or the IIGS (or both).

Looking around I came across one marked with the Fujinet project on it. I found the Github for the project. This is a project I hear about on videos and such, but not one I am following. It they make a version of the Fujinet for the Apple II and the IIGS, and this adapter board must be for connecting up certain models in certain situations. I don’t know much about Fujinet, but this is not the exact use case for the adapter, so I still had some concerns this wasn’t exactly what I needed. They do have all the specifications and schematics, as well as build photos of the adapter on their github post, which is helpful. This adapter uses male pins pulled from a DE/DB Male type connector and a 3D Printed DE19 shell cover to make a DE19 to IDC20 adapter that perfectly fits to the IIGS. The Gerber files and 3d models are all there for download. https://github.com/FujiNetWIFI/fujinet-hardware/tree/master/AppleII/DB-19M-Adapter-Male-Rev1

This adapter is not exactly what I wanted as I wanted to be able to use the 5.25″ drive in combination with the wDrive, but it is what I needed at a minimum to use the wDrive with the IIGS. I downloaded the Gerber files, then ordered 5 boards from JLCPCB. It was under $5 including shipping as I got the cheapest shipping option (which is as cheap or cheaper than shipping for an adapter). The adapter was easy enough to build.

Thanks to the DE15 Male connectors I purchased to make up RGB Monitor cables for the IIGS, I had DE Male Pins. I pulled enough pins from the three DE15s I am using for those cables to have 19 (and a couple extra) pins to make up this adapter. As they are not very tight in the connectors, they were easy to remove without damaging them, I don’t know if the pins are normally that easy to pull as I haven’t tried before (I suspect they are tighter in high quality DE connectors)

I then printed the 3d Model for the shell. I had to get the spacing right on how far to push the pins through the PCB and have the right depth. The instructions/guide shows someone having hacked up a DE25 female connector into a DE19 to hold the Pins in for proper placement for soldering. I didn’t want to ruin a DE25 female connector. So I put the pins into the DE25 and used the printed 3d model to get the spacing close. If I had expected to make more than 1, I probably would have taken the time to hack the DE25 down, it was old and not in very good shape. It would take some effort to do that with the tools I have available to me, more than I would have wanted to invest for making up a single adapter.

I soldered in the end pins on each side. I then checked the alignment of the remaining pins and soldered them all in. This did make the complication that now I had to manage to put the 19 pins into the 3d printed part without bending them. Thankfully that was not hard though.

To make this adapter I did only need to buy the PCBs. I used a piece of dual row pin header for the IDC20 port. This did mean I didn’t have the Shroud that has the alignment notch in it. The 3d model didn’t have that build into it. I found a OpenSCAD model for download, set it to 20 pins and printed it out. Having a 3d printed Shroud probably won’t be as durable as a molded one. I did assemble the adapter and put it in the shell though. It worked.

The wDrive looks like a very small 3.5″ drive from the “top” or “bottom”.

The interesting design to the wDrive case is that when placed with the LCD and buttons downward, it looks just like a 3.5″ disk drive. That does make the LCD not usable, but there is a work around for that by using the IIGS to control it with the menu system, it is also small and easy to flip over to use the screen and buttons if needed.

I looked around for a IDC20 shroud. I found exactly what I needed. Someone had made a OpenSCAD model and posted it for download. https://www.thingiverse.com/thing:3200902 They didn’t list it as being an OpenSCAD model, but thankfully it was. I was able to set it to a IDC20 size and print it out in the same filament as the case for the adapter.

It didn’t quite fit, it was slightly to large. I wouldn’t have scaled down the thickness though of the shroud as being 3dprinted it already won’t be quite as strong as a factory part (made with PLA at least). I shaved the opening larger on the cover. I got it to be a good snug fit.

Shroud
Original Cover
Enlarged Opening
Dry Fit Test
Dry Fit Test

After I had it fited, I put the case together to make sure it was aligned well. Then I took it apart and used SuperGlue and Baking Soda all around the inside rim to secure them into one solid piece.

Once it was cured and I had cleaned off any loose Baking Soda, I put the completed adapter together.

The filament I used to print the case is Polymaker PolyTerra Muted White PLA, as recommended by the MacintoshLibrarian on Youtube awhile ago. It was available recently, but I’m not currently seeing it listed. The case of the IIGS is a bit yellowed, and it is a close match to it but still a bit lighter. You can see the wDrive stands out against it, being the wDrive’s case is 3d printed in what appears White filament.

I did work to merge the two parts. Below you can see the merged part as well as the two independent parts which are shown above. It was simple enough to combine the models in Tinkercad. The opening is a little too small as seen above, so once I had them lined up properly they worked very well as a completed part with no gaps. I just had to get the offset correct, as to how much it needed to protrude into where it would come in contact with the PCB inside.

With the individual parts, there is no support required, but it does take more work to make the two into one part as seen above. I think it is worth the 2grams of support material and 10 additional minutes to print them as a single part. The finish of the part isn’t quite as nice as the outer surface is not face down on the print bed, I do have it positioned so that the “support” is on the interior of the case though so that the supported areas defects won’t be visible once assembled. I did print one of these combined parts to see how it went. It was pretty good, and I may use one of the other PCBs and build up a second adapter at some point using this new combined part. It might actually be possible to take that outer 3.25mm protrusion off the outside, making the outer face flush again. That may retain enough shroud for a good positive fit, but then let it be flipped back over and printed with no support (or only a tiny support at that little bit of overhang where the notch is for the alignment on the IDC).

PCB Solder Bridges

The PCB has several solder bridges. For the first adapter I did not connect them. They are for the 12V and the -12V and Drive 2 Select. Since there is no pass through, and I am not connecting something that uses those voltages, I didn’t connect them up. I am not sure what the Drive 2 Select does, or would do. The wDrive doesn’t use the 12V or -12V, so I don’t have any reason to connect them up at this time. Other adapters that I have come across do tend to have them connected, which is required if using “real” disk drives. It is still unclear to me how the Drv2 jumper should be set, or what scenario requires 12V on it.

There is no Pass Through port, so I expect I would only have “Drive 2″ if it actually does change the selection.. I was thinking maybe I could make one of these up with 90degree angle headers and connectors and that would be able to be plugged into the back of the 5.25” drive letting me use the wDrive as Drive 2. I’ll have to find out how Drv2 works or should be used if I ever do that.

It is nice having the Shroud on the IDC20 port, so I can’t connect the cable backward. That was the other reason to not connect up the 12V and -12V pins incase that ever happened. I only had the red dot to mark where the Red Stripe goes to let help me ensure I didn’t get it backward, also there had been enough room in the IDC20 port opening to plug the cable in off by 1 pin, which tends to go badly as well.

This adapter and the wDrive will let me do a lot more with the IIGS than the two good floppy disks I have. What little I have found on the IIGS so far, shows me there is a lot more to the Apple IIGS than we ever took advantage of in school. I do hope to find the time to get to know the machine better.

I did do a little testing with the wDrive, but not much, I tried out a few other programs and such, I want to try out the GS OS graphical interface. I need a mouse for that, and I have one on order that is supposed to be tested and working.

I have a few more things to do with these machines. I have to finish up the RGB Monitor cable and SCART RGB Cable, which should be next (they are made now, I just have to finish the posts and get a couple of the SCART shots of it in use and a bit more testing). I still have that filthy and messed up keyboard that I don’t want to touch, and then to do an internal clean and maintenance on the other two 5.25″ drives so I know their condition. I need to get a battery as well the next time I place an order at Digikey, or somewhere else that I trust to get quality parts from.

Apple IIGS Maintenance

I ended up with 2 Apple IIGS computers. They were nearly complete. They were dirty, a lot of evidence of mice or more.

I did a basic wipe down of everything to get some of the nasty stuff of of everything before loading them up to bring them home.

On inspection at home, overall I had 2 Apple IIGS computers, with keyboards and the cables but the one keyboard has keys that are stuck and some damage. I also have 3 5.25″ disk drives, a Color Monitor (minus the cable), and a Monochrome Monitor.

I will be making various posts going over the equipment.

The primary thing was to check out the IIGS computers. I needed to see if either was working or reasonable to repair.

I focused on the first IIGS. First I cleaned it a bit better as it was still not very clean. I had checked both IIGS internally for leaking batteries, and thankfully neither battery had leaked, they were dated 1992. On seeing that they were in battery holders I was able to look up that these are the later ROM3 version boards with ROM3 and the additional ram. I removed both batteries, and gave the boards a visual inspection, they looked fine, a bit of dirt and dust.

From there I went to the power supplies. I opened the first one, it is apparently an ASTEC model. The visual inspection of the top looked pretty good overall, although the RIFA cap has some cracking. Nothing scorched or bulging etc otherwise initially.

On removing the PCB from the case to get to the RIFA cap, I found a surprise on the bottom. Under the Large Filter cap (C4), was a leaky black mess. Over toward the nearby C5 there was a mess and the solder mask and solder points looked bad nearby.

I first cleaned up the muck with some IPA while I was preheating my desoldering gun.

I pulled C4 and C5. The large C4 had no marks under it, it didn’t appear to have leaked. C5 though showed evidence of leaking. I take it leaked and migrated across the board, possibly through that large hole or somehow it managed to leak through the board some other way. There is a small pin hole under C4, but there was nothing on the top side, though the hole was plugged up with the gunk. The solder was quite contaminated around a good number of those solder points, and was a bit difficult to remove that old solder from those corroded points. I then had to use the fiberglass brush to remove some of the solder mask where it was damaged and the traces were corroding.

I used my MESR-100 ESR Meter to check C4 and C5. I also checked their capacitance. The large C4 330UF 200V capacitor had the proper Capacitance reading and a good ESR Reading as well. I reinstalled it. With C5, I was surprised to find the capacitance on it was still in spec for a 220UF capacitor, but the ESR was way to high. I’m fairly certain it was where the leakage came from as well, unless it was something that somehow ended up falling into the power supply. I replaced 220UF capacitor with a new one I had in stock. The board isn’t beautiful, but it cleaned up fairly well, everything was superficial. I removed the RIFA, and as I don’t have any spares in stock, I am just going to use it without one to do the testing and get one on order. I removed one of the resistors that had corrosion on the legs, and cleaned it up a bit before soldering it back in.

Above, it how the pcb looked after cleaning up the old solder and resoldering everything. The 3 now vacant holes in the upper left are the holes for the RIFA cap.

I tested the power supply output, and the +5V, -5V, +12V, and -12V all looked good. The +5V was right on, the others had a little variation being a bit low.

The other power supply is a Dyna Corp model. It has 4 RIFAs in it. It also has heat discoloration on the PCB.

I decided I wasn’t going to remove the 4 RIFAs, and that with the state of the PCB (and that I don’t “need” 2 working IIGS computers at this time), that I was going to just close this Power Supply up and not use it.

Now that I had one power supply working, I decided to test both mainboards with it. Since I didn’t know the condition of either monitor and I don’t have the RGB Cable, I used my bench LCD monitor with Composite video. Both mainboards powered up and showed the expected display.

I moved on to one of the Disk Drives. I just picked one of the three drives to do a cleanup and service it. I cleaned the case and cable with Windex and paper towels. I then took it apart. It was a bit awkward to get the drive out of the shell with how the front faceplate locks into the top and bottom halves. I then had to remove the top metal plate, and then the PCB and insulator and other plate below it. From there it was dusty inside, but looked fine otherwise.

I cleaned it internally with qtips and IPA. I cleaned as much of the dust from inside, as well as the rails. I also cleaned the print head with a fresh qtip and 99% IPA. I then put in new Silicone Grease on the rails and worked them a bit to make sure it was distributed well.

Just before putting everything back together, I saw something in the bottom of the drive.

Thankfully I found that and removed it before powering it on. Old gum wrappers some fool stuffed into the drive slot. With one of the drives, I wasn’t able to fully insert a disk into it before loading them up to bring them home, by the time I got home with them, I was able to insert the disk fully. I expect that was this drive, and that had moved out of the way.

I was still testing the IIGS, so I decided to test the Disk Drive before putting it back in the case.

The drive worked properly. I wasn’t making any unexpected sounds, and read the first disk just fine. I had 3 disks, and I tried the other two, and one of them worked. The last disk did not work properly, it would partially read but get to a point that it said to insert the proper disk.

That little Eyoyo monitor does a great job with Composite. It is very forgiving, and I expect when using any of my other monitors on Composite video won’t look as good.

Unfortunately Oregon Trail is not one of the disks, so that means I will have to get solution to let me play it on one of these machines. There are some other programs I would like to try out as well. I have more cleanup to do, the IIGS cases are a mess as well as everything else yet. One of the IIGS cases must be brittle, the lower frame as the one catch that holds the top was already broken when I got it, and then the second one broke when I opened it.

I finished cleaning the Disk Drive’s case and reinstalled it. I also cleaned up the intact keyboard just enough to use it, and it seemed to be working fine. I didn’t test all of the keys.

I found out these will not pass their self diagnostic without a good battery. I need a battery, and replacement for the RIFA cap. I also have to properly clean all the other parts including the IIGS cases.

TI 99/4a 32k Memory Sidecar Alternate Memory IC Adapter

I recently built a Jedimatt 32k Memory Sidecar for my Ti 99/4a computer. https://hobbytronics.home.blog/2024/05/04/ti-99-4a-32k-memory-sidecar-build/
This was after having a Backbit 32k Memory Sidecar module that was not working properly.

When buying the parts for the Jedimatt 32k build, I purchased a new SRAM IC for the Backbit 32k unit. I replaced the ram IC on the Backbit 32k unit and it still wouldn’t work, reliably. That indicates some other fault on it, either the CPLD or somehow the Edge Connector on it not making proper connection. It will “randomly” work for a short time then quit again.

The Static Ram I purchased for the Jedimatt 32k unit uses a Low Power CMOS 28pin 256-Kbit 32k x 8 Static RAM that is TTL Compatible that runs at 2.7V to 5.5V. The Backbit 32k unit uses a CMOS 28pin 256-Kbit 32k x 8 Static RAM that is TTL Compatible that runs at 4.5V to 5.5V.

I looked at the Datasheets for the two of the Static RAM ics. With one being branded Alliance Memory and the other Cypress, although both list Alliance Memory Inc as the manufacturer. I looked over the pinouts, and they are pin compatible, short of the Address inputs are numbered differently. The primary difference is the footprint. The AS6C62256-55PCN that I purchased for the Jedimatt 32k build is a 28PIN 0.6″/15.24mm Width DIP Package. The CY62256NLL-55SNXIT that is on the Backbit 32k is a 28PIN 0.295″/7.5mm Width SOIC Package.

I purchased some SSOIC to DIP Adapter PCBs. I had assumed they would be sized to adapt to the 28PIN 0.6″/15.25mm Width. I was wrong, they are wider. They are also the narrower SOIC Footprint, which happens to be the same footprint on the Backbit 32k PCB. That meant the CY62256NLL already had the legs bent to go on the narrower footprint, which by the way, is no fun doing. I guess it would have been to easy to just solder the CY62256NLL-55SNXIT to the Adapter and put on the Round Pin headers.

I started with soldering the CY62256NLL-55SNXIT to the Adapter PCB. I then installed a row of Round Pin Headers in Pins 15-28. This is because of where it needs to fit on the Jedimatt 32k PCB. I next need to install a row of offset Round Pin for Pins 1-14.

I went back to the same Round Turn Pin Sockets that I had used on the Jedimatt 32k Edge Connector. I installed the Round Turn Pin Socket row into a Round 28Pin IC Socket. This is why I used the Round 28Pin IC Socket instead of the standard dual wipe 28Pin IC socket that I specified in the parts list for that build. I then inserted the adapter board above to find the spacing I needed to get everything aligned.

Once I had it held in the spare 28Pin Round Pin IC Socket, I took some Solid Copper Wire (a strand from some Cat 6 Solid Core Copper Network Cable) and stripped the insulation from it. I shaped it to fit into the Round Pin Socket. I made up a total of 14 pieces.

Copper Wire
All wires inserted. They can flop around though.

Above you see the little copper wires as fitted into the Round Pin Header. I then placed the PCB onto the wires to Hold them in proper alignment. Once they were held in place, I soldered them into the Round Pin Header Socket.

Aligning the pins while soldering
After Soldering
Another angle

Once the copper wires were soldered, I installed the Adapter PCB into the spare IC Socket and soldered the wires into the PCB to get the proper alignment for everything.

Installed to Solder
After soldering and trimming
I was sure to fill the holes.

With it upside down, I then made sure to have good soldering on the bottom to help the Copper Wires keep secure. The bottom of the PCB had Kapton Tape on it to keep the Copper wires from wearing into the solder mask and shorting over time. Now the adapter board is all soldered up. It was time to see if it will fit.

Time to pull the Socket.
Here you see the Kapton tape
It is a close match.

Below you can see it installed into the PCB. I guess now the Green PCB is fine as they look good together.

It is just barely up over the case. The Top Cover has a hollow in it though so it will still fit.
I think it looks great.

It was time to power it up and see if it works.

It seems to be stable and working properly. I am going to leave this CY62256NLL-55SNXIT on the adapter PCB installed into my Jedimatt 32k Memory Sidecar. I will put the 28PIN DIP Static Ram IC back in my spare parts. I have 4 more Jedimatt 32k PCBs that I could build up. I may still try to revive the Backbit 32k Memory Sidecar, but if I don’t, I could at least salvage the other CY62256NLL-55SNXIT and the Edge Connector to build another of the Jedimatt PCBs.

8/31/25 A little update on the Backbit 32k Memory Sidecar. I did buy a new CPLD for it a while ago, but before installing it, I decided to strip down the whole board. I removed the 5 Caps, the Edge Connector, the ram and the cpld. I cleaned the pcb. I reinstalled the Edge Connector flipped 180 degrees, I felt it potentially was a contact issue, and flipping the connector may make a difference. With the edge connector “pins” being flush with back holes on the pcb, it may have had a bad solder joint in one of the pins where the solder didn’t flow properly to the pin? I then soldered the Ram IC, CPLD and finally the capacitors back on. With practice I have been doing much better with soldering the CPLD. Also with good flux, and a new microscope for inspection. The primary issue with the board was solder bridges, some very small bridges kept hiding between the CPLD pins, but the new microscope made them much easier to see. After cleaning and reinspecting the pcb, it is working in the TI 99/4a just fine. I tested a couple 32k programs and they started fine, I have been running Jedimatt’s Expansion Memory Test Burnin as seen above for over 20 passes on it. I’m glad it is finally working reliably. This does mean I now have two 32k sidecars, for now I think I’ll use the Backbit one. I also have a spare CPLD, the primary reason I reinstalled the original one is I really don’t know how to program the new one, as to if I can use the same method I have used for the ZX Nuvo 128 board, or if I would need a different programmer. The board also does not have any traces going from the JTAG pins, meaning soldering on very small wires to very small pins to even attempt it. There may have been a bad solder connection or bridge, or it may be the edge connector in some way. I did find that the Andonstar 246S is a great upgrade over the little lcd microscope I had previously. It is much clearer and I could see the solder points and solder bridges that needed to be cleared. It has enough clearance to the microscope that I can use it to view the screen while soldering.

TI 99/4a 32k Memory Sidecar Build

I have had the TI 99/4a for awhile now, and posted the Recapping of it. I actually have two TI 99/4a computers as the first one had a bad membrane type keyboard. The second one had a Stackpole type keyboard, which is is working order (although some of the square tubes are split). The Joysticks are awful, and I built up a Joystick Adapter to plug in Atari 2600 compatible joysticks to it. That made things much better for it. I also built up a Pitfall Cartridge for it and 3d printed a shell. Still I haven’t used it much. The Ti 99/4a was the first computer I had, it was old at the time. I had a few cartridges for it, and used BASIC in it at the time. It was quite limited with all the more software I had available.

In anticipation of getting a FinalGROM Cartridge or Backbit or something, I had purchased a 32k Memory Expansion that was for sale from Backbit. After I received it, I designed a 3d printed case for it. It turned out really well and has been sitting with my TI 99/4a since then, but I was unable to use it at the time.

I like the small and clean look of the Backbit 32k.

The FinalGROM Cartridge came in, I made up an SD Card for it. I tested it with some games that did not require the 32k Memory Expansion. Then I plugged in the 32k Memory Expansion and the 99 wouldn’t power up properly, it just made an audio buzz. I checked the contacts, checked the Memory Expansion. I noticed flux residue on the ICs of the 32k Memory board, and cleaned that off just incase it became contaminated. I ended up removing the CPLD from the board, and inspecting it. I soldered back on the CPLD, and the buzz was gone, and I got it working just one time. Then I powered it off and tried another 32k program and it quit working again. I rechecked the soldering on the CPLD, as well as the ram IC and edge connector and touched it all up. It would randomly work, it may pass Jedimatt’s Burning Ram test for a few passes then fail. Then it generally won’t detect the 32k memory until it is powered off a bit and reseated.

Backbit has quit selling the 32k Memory Expansion, and has released on Github as a project to allow you to build your own.

The Backbit 32k is more compact, and should be cheaper to make than Jedimatt’s design if you have all the required equipment to program and assemble it. Jedimatt’s 32k which is available to build by ordering PCBs with the provided Gerber files and standard components. Jedimatt’s 32k requires no programming of components. There are a few issues with building the Backbit 32k. It has a CPLD and that requires programming with a JTAG programmer. The board doesn’t have a JTAG Header. I believe this is simply due to it not being designed as a DIY Project, Backbit is a business and she makes and sells her products. I later found the RAM IC Footprint is wrong, at least for the ram IC that was fitted on mine when I bought it. The CPLD is on the top edge of my ability to solder with the super fine pin pitch. The Backbit 32k has not been around nearly as long as Jeditmatt’s, I can’t be sure that the problem is a defective part. It may also just not like my specific Ti 99/4 for some reason.

Jeditmatt’s 32k design has been around for many years. It is all through hole style components and easier to solder together. Surface mount soldering is not that difficult with some practice. That is at least for the larger parts, the smaller pin pitch like the CPLD gets far more difficult for me.

https://jedimatt42.com/4a/ti32kmem/

This left me with a problem. I know I can build Jedimatt’s design, I know it is thoroughly tested. It takes way more parts and time to assemble, and is also more expensive to build. I just love how the Backbit 32k looks. I also currently have no interest in a TIPI which does require Jedimatt’s type of expansion.

I looked around and found a Jedimatt type expansion for a reasonable price with shipping. I would rather build it though. I looked into it. I found all the required parts at Digikey. I also found the Ram and CPLD for the Backbit 32k there.. I also found a more “stylish” case for the Jedimatt 32k board on Thingiverse.

I decided to order the parts for Jedimatt’s board. While I was at it, I did order a replacement ram chip for the Backbit 32k board. I could have picked up the CPLD as well for $3.50 or something. I wasn’t interesting in trying to hand wire that for the JTAG programmer at this point (I may next time I place an order).

Jedimatt’s 32k Parts List. I have provided links for more specific parts. The most generic parts can be purchased easily. I included a link to the type of Round Female Socket Pins that I used, Digikey does have them as well if you are willing to look for them.

I downloaded the Gerber files from Jedimatt’s site. Then I went over to JLCPCB and ordered the boards as that is where I order my PCBs from. I managed to order 5 of them and have them shipped to me for a total of $4.11 ($2.00 for the boards and $2.11 for shipping and taxes). I did kind of mess up, I didn’t want them in Green, but forgot to change it. The other colors did list they would take 2 more days to ship though.

I placed my order with Digikey for the parts I required. Between the PCBs and the Digikey order, I paid less than I would have for a completed 32k Memory Module on Ebay. I did have the 74HCT138 already, as well as the Resistors, Capacitors, 2.54mm Pin Headers, 2.54mm Jumper, DC Power jack, LED. I am also 3d printing the case. I ordered 5 of each of the 245s and 21s as well as two of the ram ics (and a replacement ram ic for the Backbit 32k incase that was the fault there).

First the Backbit 32k. I replaced the ram ic. The one I ordered was the exact part number that had been on it. I had the same results. Initially I couldn’t get it to work at all, once it made the buzz on power up, on removing it and trying it a few more times, it just failed every time I ran the RAM Test on it. It then worked for a little one time.. So it is on the shelf incase I want to buy another CPLD for it at some point.. I am wondering if it may be the edge connector is for some reason not making good contact. I am thinking I may get out the other TI 99/4a to see if it works on it. That one has no keyboard in it though, and I can’t start the ram test without one. The keyboard for it may be just working well enough to do that though if i reinstall it..

Next I moved on to the Jedimatt 32k build.

The boards came and looked great as usual.

The part that needed the most consideration was the Edge Connector. The edge connector that I purchased is of the same series as the one I purchased to replace the Cartridge Connector on my Commodore 128. Being that the connectors are the same 44pin, the difference between is the one for the Commodore 128 was a Right Angle connector. Being how it worked with the Commodore 128 I figured it should work for the TI 99/4a. It needed modification though, to remove the “mounting hole ears” on the side just like it had with the Commodore 128. This was a bigger deal here due to fitting in the 3d Printed case, the opening is very tight, and I needed to file it down a bit smaller than I thought I would.

There is a difference between the Edge connector between the Jedimatt and Backbit 32k. Jedimatt recommends some “individual pins” to use as extenders on the Edge Connector. It doesn’t seem they are available. I used Round Pin Female Socket strips. This is required because the “legs” of the Edge connectors are too short to reach deep enough into the side of the Ti 99/4a, or into the pass through socket of other Sidecars like the Speech Synthesizer.

I printed out the case and fitted the board to check how far the connector came out. With no pin headers in between it was way to short. I then tried with 1 pin header to see how that fit. It was still to short, compared to the Backbit 32k. The Backbit 32k didn’t use pin headers to extend the connector, it was cheated a bit by not putting the edge connector pins the whole way through through the PCB. The 3d printed case I made for the Backbit 32k is much thinner than the cases designed for the Jedimatt 32k (or at least the one I am using). I could rework the 3d printed case for the Jedimatt 32k, and maybe I could have managed then with a single pin header to extend it. That was not something I wanted to do though, it would have taken a good bit of work on the model.

That meant I needed to stack 2 of the Round Pin Female header pins for each of the 44pins of the edge connector. Which required stripping out 88 of the Round Pin Female header pins. The next step was to insert them into stacks of two each. The stacked pins were then soldered together, holding them with my Helping Hands. I went to stacking 5 pairs at a time and standing them up in holes in the PCB by the time I was done. While it was a bit awkward being they could spin around and even be picked up by the solder iron, that was quicker than trying to get the alligator clips in the Helping Hands to hold them properly.

The pin header strips before removing, then the individual pins, a pair of stacked pins and in the middle a pair soldered.
Starting to put the pairs of pin headers on the connector.
The connector installed.

That was a lot of time consuming work. Stripping the 88pins out of the strips without loosing or damaging them. Then stacking and soldering them together in pairs without making an awful mess of it. Then installing them onto the modified Edge connector that I had taken the wings/ears off and sanded down a bit more to fit through the 3d printed case.

To get the alignment correct, I fitted the pins and edge connector into the PCB. I then soldered the 4 corner pins into the PCB. I then aligned the edge connector and soldered the 4 corners of the edge connector to the pins. This let me align it all nicely, and after that it was easy soldering the rest of the now captive pins to the Edge Connector and PCB. Doing the soldering that way worked very well. It is very solid, it doesn’t look too bad overall once it was finished. I had tried to find what other people were using to extend the Edge Connector, it looked like one example was using the same Round Pin Sockets stacked up.

Jedimatt & Backbit Height
Jedimatt 32k fitted
Backbit 32k fitted

Above you can see the Jedimatt 32k Edge Connector does extend just a little bit higher than the Backbit 32k Edge Connector when they are in the cases. That was the closest I could get it with using the Round Pins to extend the Edge Connector. That does make it have a bit more gap between it and the Speech Synth Sidecar and or the TI 99/4a. I am thinking of that “heatsink looking” interface bit on the side of the Speech Synth Sidecar where it meets up to the TI 99/4a. I could make one of those and stick it on the Jedimatt 32k to support the gap in a very similar way.

The Backbit 32k has a serious time advantage due to not needing to extend the Edge Connector pins. You can see below the BackBit 32k just solders in the Edge Connector, keeping the pins as barely in as possible to extend it out as far as possible. You also see it has far less components overall. (Update 8/31/25 the Backbit 32k is working now, I striped it to be the bare board, flipped the edge connector 180 degrees and reinstalled the ics and capacitors, and with a new microscope I could inspect the work properly to clear any solder bridges and see that all the pins were soldered properly)

Backbit 32k



The rest of the Jedimatt 32k build is strait forward through hole soldering. Keep in mind that you have to install the Jumper for the Power Selection. To the front it uses the 5V from the Ti 99/4a Expansion port (requires a mod to the Speech Synth Sidecar to use), and toward the back of the TI 99/4a it uses the Power Jack and you need to connect up a 5V Power supply. Be sure to only use at 5V Power supply. I am using the Ti 99/4a to power it from the Edge connector with my modified Speech Synth Sidecar. Also install all the ICs on the board in the correct orientation, Pin 1 toward the Capacitor.

The case design intends the LED to tight to the board. There is a “clear” lens bit to print. I am not sure how that is fitted and decided to mount the LED pointing out through the hole.

As modeled
Impacts the Screw here.
Removed a bit so the screw fits.

I had taken the top out of that circle so the LED would clear, but on trying to close it still didn’t close. On pressing it a bit, and then opening the case, I saw that the screw in the corner hit that one spot around the LED housing. On removing a bit of the plastic there, the case then closed properly. I printed it in a Silver and Black theme to fit the TI 99/4a color scheme. The 4 screws are not specified, I used four 2mm by 10mm long screws and nuts (or 2.5mm, but I believe 2mm), a little shorter screw may have cleared the LED housing..

I connected it up and ran the Ram Burn in test on it. It passed all the tests for 12 cycles, then found an error on one of the banks. I powered it off and back on, and ran the test again, it was working again. I am not sure the issue, or if it was a random failure. I did do some more testing with it today, and it worked properly. I tried out a few 32k Games and Programs all of them ran fine.

The case printed reasonably well, but has room for improvement. The Silver is a sliver PLA, the 99 4 and A had little nearly “floating bits” that are missing. They were all partly there, but due to a defect on one and the poor strength of those bits, I removed them. I am thinking of possibly reprinting it as a 2 color print with a black insert filling in the letters to give it strength to retain the floating bits. I didn’t print the “inner blocking piece” You can see the PCB and parts inside through the openings. The back is printed in Black PETG, the case itself is a snap/friction fit top. The screws hold the PCB to the Bottom, but do not hold the “top” on.

Jedimatt 32k
Backbit 32k


The Speech Synthesizer doesn’t pass 5V through it without a modification as shown on Jedimatt’s website. You can alternately use the external 5V Power Jack to power the 32k Memory expansion. If you have built either of the 32k Memory Expansion Sidecars, it should be no problem to add the wire to connect the 5V Pin in the Speech Synthesizer.

I did a little side project based on the Jedimatt 32k. I made an adapter to use the SOIC Static Ram that the Backbit 32k uses fit on the Jedimatt 32k. It is currently running on the 83rd pass of the Jedimatt 32k Ram Burnin Test. https://hobbytronics.home.blog/2024/05/05/ti-99-4a-32k-memory-sidecar-alternate-memory-ic-adapter/