Commodore 64 mod of the year 2015 with a paint mod, sid2sid stereo mod, sd2iec mod, potentiometer mod, JiffyDOS mod, capacitor mod, voltage regulators mod, heatsink mod, PLA mod, RESTORE key mod and power led mod

Mod of the Year 2015

…well almost… The machine still needs some new colored keycaps (hurry up Phase5!!!), a domed sticker at the bottom and a cold reset button using an Arduino Pro Mini. But I gotta have some modding goals for 2016, right? This machine has been build from a broken Assy 250425 Rev. A breadbox. The motherboard was the the first one I bought when I picked up the interest for the Commodore 64. It had a black screen which was easily fixed with a new replacement PLA (MOS 906114) at U17. The case was from another repair job that I ended up painting and decided to use it to host the PCB. The entire ‘Mod of the year 2015’ mod is a compilation of several previously described mods as well as a few new ones. I’ve worked on the machine for quite a while and eventually decided to finish it so I could do a little post about it. This is the complete list of what I have done on the breadbox so far:

Paint Mod
SIS2SID Stereo Mod
Potentiometer Mod
JiffyDOS & ROMs Mod
Capacitor & Voltage Regulators Mod
Heatsink Mod
Power LED Mod

Paint Mod

The breadbox case was really dirty when I got it, so I thought, ‘Hey, let’s see what 90 minutes at 60°C (140°F) in the dishwasher will do to it’. It was certainly clean when it came out, but the color of the case had faded and looked really bad. So I painted it with some Molotow spray paint in anthracite grey. In my own opinion, the result is not that bad! Now I just need some orange function keys and a stack of black keys to finish the looks of the keyboard.




The machine has a sid2sid pcb installed so I can play stereo SIDs from the HVSC SID collection. To connect both channels (left & right) a pair of stereo phono RCA jacks have been mounted on the back of the case. All I have to do is attach some phono cables to my stereo receiver and I’m ready to go nostalgic!


A new Commodore 64 label from Ebay was also added…


Four potentiometers for controlling music carts like Mssiah and the CynthCart.


Internally installed SD2IEC PCB for all my gaming needs. The SD card can be inserted/released without opening the case. The green and red LEDs (disk activity and disk load error) have been mounted to the metal bracket as well.


I still have to make a 3D domed sticker for the bottom, but having just a few copies made is ridiculously expensive! I hope to find someone who will print them at a reasonable price in 2016.



The PCB is an Assy 250425 Rev. A and it is in pretty good shape. This is the inside of the machine. I have tried to make the cable mess as neat as possible.





The SD2IEC is a mass storage device which uses a SD card for data storage (i.e. games and programs) and interfaces with the IEC bus. The most common use of the SD2IEC is as a replacement of a Commodore 1541 diskette drive. It does not emulate the diskette drives completely like the 1541 Ultimate II, but it reads quite a few .d64 and .prg files. And most importantly, it supports JiffyDOS natively!


I got the PCB from thefuturewas8bit which carries it in various versions (internal & external cased versions). I wanted an internal install of the SD2IEC and I did not want to make any cuts to the case itself. I found the best location to be at the metal bracket between the joystick ports. A small rectangular piece was cut out to make just enough room for the device to stay clear of the top part of the case.



The internal install version has a pin header for attaching a disk swap button and two LEDs (usually a green and a red). The disk swap button is essential whenever a game comes on more than one disk. Pressing the button will swap the disk and automatically load the second disk. To use this feature, special files must be created and placed in the specific game directory. To reassemble the diodes of the original Commodore 1541 Diskette drive I installed a red LED which flashes whenever there is a disk load error and a green LED which shows disk activity.



The SD2IEC must be soldered to the 5V+, Data, CLK, ATN and Ground lines of the IEC (Serial Port). The grey wires are all for the SD2IEC, while the blue wire is the sound signal for the SID2SID stereo connection.  

The SD2IEC is fixed to the motherboard using the screw holes for the joystick ports.


Two plastic spacers were used to get the position of the device correct.


Two small screws were used to tighten the PCB to the spacers. The SD2IEC comes with two holes already made. However, to get the screws into them, the SD-card slot has to be removed. It took me 3 SD2IEC PCBs before I got reassembled one that would actually work after the operation – so do this mod at your own risk!


Here is an image of the spacers mounted between the SD2IEC and the motherboard.IMG_5896

The disk swap button goes out the back at a non-occupied hole next to the RF-antenna plug.


11 thoughts on “Mod of the Year 2015

  1. Very nice mod, love the placement of the sd2iec an its LEDs. It would have looked even better if the pots where fastened on an added plate inside the shell so there was only the knobs on the outside and not the nuts as well – same goes for the RCA connectors, would have looked nice countersunk.

    Love the color, looks a little blueish in the pictures (at least on my screen) but I guess it’s just dark gray?

  2. Thanks e5frog! The placement of the SD2IEC is what I think turned out the best in the mod.

    You are touching a bit of a delicate topic with the pots as I actually did make a plate for an internal install. However, the attachment of the plate was a little tricky (at least for my building skills) as I found that hot glue would be the best way to fasten it to the inside of the cabinet without having to drill more holes. At that time I already had the RCA connectors mounted (nuts on the outside of the case) and thought I would go with a more ‘rugged’ look for the machine. I therefore ended up placing all the nuts on the outside of the case.

    The color of the case i anthracite grey (Molotow spray color #223), which may have a little bluish teint to it, so you may be right :o)

  3. Hey, this is amazing! Would you please post a tutorial on how you made this? Including soldering etc.??

  4. Hi Ben, thanks for the comment. The different mods should be possible to re-create directly from the post 🙂 Some of the mods are described in furher details in other posts on the site – just follow the provided links at each of the individual mods for in-depth explanations. Let me know if you get stuck and I’ll try to elaborate further.
    A tutorial on soldering may be better to find on-line. In my experience, soldering is a craft and practise makes perfect 😉 The best way to learn is to get a good soldering iron and some lead-based solder and you should be half way there – the non-lead stuff is really hard to use!

  5. Hi there! The SD2IEC is fixed to the motherboard using the screw holes for the joystick ports and two plastic spacers with machine threads on the inside (link and link). As the distance between the screw holes of the joystick ports and the holes in the SD2IEC device fitted almost perfectly, I used another two screws to attach the device to the top of the spacers 🙂 However, I had to unsolder the SD-card holder to get the screws into the holes. I broke a few devices before I managed to get it working – so be careful if you consider doing the mod!

  6. Thank you for explaining this. I love your mod. It is really high quality and not a cheap looking thing many other people did. Very rare to see mods like you did.

  7. Thanks Alex 🙂 I usually try to avoid cutting in the C64 cases, even though I did in this particular case with the potentiometers and paint. Happy to hear that you liked it 🙂

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