I Turned A Raspberry Pi Into A Commodore 1541 Disk Drive ...

Here we go with another Doom-It-Yourself project by your host NCommander where we build a Pi1541 (https://cbm-pi1541.firebaseapp.com/) for my Commodore 128. This entire project got started because I had a desire to explore Magic Desk I for the Commodore 64, I quickly discovered that my SD2IEC was not up to the task of running some really bad software. This was a problem because I don't have any real Commodore disk drives on hand. However, Steve White has created an cycle accurate Commodore 1541 disk emulator out of a Raspberry Pi 3+. This means its possible to accurately emulate the behavior of a Commodore disk drive, and for those who have the (mis)fortunate to own a Commodore 128, its one of our few modern disk emulation solutions.

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Interesting Timestamps:
00:00 - Intro
01:08 - Pi1541 Overview
01:40 - Soldering the Pi1541
04:08 - Smoketesting the build
05:00 - LCD Troubleshooting
06:30 - Smoketesting 2.0
08:00 - Retrotink Problems
10:52 - Initial Successes
12:00 - Further Pi1541 Testing
13:00 - The 1541 As Compared to Amtrak
13:58 - 1571 Disk Drive and Acela
15:40 - The 1581 and NJTransit
16:30 - GEOS128
17:02 - CP/M Problems
18:21 - CP/M and the 1541
20:20 - Final Thoughts and Conclusions

I picked up this Pi1541 quite awhile ago as an attempt to learn more about doing electronics projects, and since I finally had reason to build it, I started documenting the process for a simple Patreon perk. However, what was supposed to be a simple project quickly spiraled as I ended up exploring the horrors that is the C1541 disk drive, exploring the 1581 emulation, and then taking a journey discussing fast loaders. While doing so, I ended up comparing Commodore disk drives to the American rail system, which turned out to be a far more fitting compassion than I could have imagined.

In short, the 1541 is Amtrak, the 1571 is Acela, and the 1581 is an on-time NJTransit train (which may be the only search result for that term; I do wonder if anyone might find that here in the description. Let me know in the comments below!).

After getting past the strangeness of that comparison, I took a dive into some Commodore 128 native mode software, and gave it a quick test with GEOS for the C128, and then trying CP/M. CP/M for Commodore machines ranges from bad to flat out awful, and the C128's CP/M is not an exception that rule to say the least.

I found that CP/M on the Pi1541 didn't work at all with the 1581 D81 emulation, but it could be made to work with 1541. Not that you should ever attempt to do so, but it does work. Slowly and painfully.

After that little adventure, I determined that while the Pi1541 is a great add-on for a real C64 (and probably a Commodore 16/Plus4), it leaves something to be desired for the 128 due to the lack of burst mode and more. Still, the author has promised to make it better so it will hopefully get better over time.

It should be noted that the Pi1541 only works with the Raspberry Pi, but this is a great project if you want to get your feet wet with a vintage computing project that's relatively easy to build.

Music used under license from Epidemic Sound.
#Commodore64 #Pi1541 #NJTransit #Commodore128 #CBM