Enter the Pi1541! What makes this different from the SD2IEC is that this emulates both the 6502 processor of the 1541 drive, it also emulates the two 6522 chips as well giving far stronger emulation. Is this enough to satisfy CP/M? Or is my issue something deeper?

So in my continuing adventure of stuff arriving for my Commodore 64 project, I took the opportunity to pull the keyboard apart and clean it. I didn’t do any weird retrobrite thing, as I don’t care that this looks 30+ years old. And I haven’t swapped out any further caps just yet, although I did also get a big box of random caps ranging from 0.1 to 220uF, so I can probably do all the small stuff on the board when I feel like it next.

The IEC cables had finally arrived, and that means I could connect up the Pi1541 hat I bought and get this project going.

Although it’s the latest ‘rev 4’ board, it doesn’t support the Pi4 (does anything support the Pi4? What an evolutionary dead end!), auction did include the LCD display, but no software, and no serial cable. The cooler looking one I wanted was all assembled in Poland and they are unable to ship.

Bummer.

Anyways, turns out the software is written by one Stephen White, who doesn’t get any cut of the board sales, but in turn I guess they aren’t bundling the software either… I’d have imagined it’d be some kind of 1+1 thing, but it’s not to be. I guess it’s also why so many people keep on thinking you can buy a PiZero for $5 or so, when they are much closer to $25.

Anways, getting the initial part of the board working was just a matter of reading Steve’s site, and following which files to be download, and where to be placed onto a FAT32 formatted SD card. This is one of those ‘bare metal’ type projects, so this also doesn’t run Linux.

Unfortunately for me the Pi1541 didn’t do ANYTHING on powering on, that is until I connected the HDMI cable. And yeah what a let down. And even worse when trying to load anything it’d just hang. So frustraiting!

But thanks to this post by jerrykurtz over on lemon64, I was able to put together this fragment to get it working (for me!)

deviceID = 8
splitIECLines = 1
scrollHighlightRate = 0.07
ChargenFont = chargen
OnResetChangeToStartingFolder = 1
GraphIEC = 1
SoundOnGPIO = 1
SoundOnGPIODuration = 1000
SoundOnGPIOFreq = 1200
LCDName = ssd1306_128x64
LcdLogoName = 1541classic
i2cBusMaster = 1
IgnoreReset = 1

Now this of course works for my v4 hat, and the way I like it. Also keep in mind that if the C64 isn’t detected it will appear to hang after loading the chargen ROM. It took a while to figure that out, until I just turned on the c64 to see what would happen. I also hate having it change disks when I power cycle, so IgnoreReset was a great feature, well for me anyways.

I fired up CP/M, and yeah it’s doing the same thing. So it turns out that it’s not the SD2IEC adapter that I have. I’m kind of mixed about this, on the one hand that’s great as the SD2IEC’s are significantly cheaper and easier to come by, at the same time I had hoped a little that the bigger investment of the Pi1541 would make the difference. At least it’ll be the difference for stuff like Ghosts’N’Goblins Arcade.

One interesting thing is that SOFT80 is now faster, getting somewhere between 1-3cps. It’s still totally unplayable, but I guess that’s progress?

Still waiting for the dead test cart to see if it tells me anything useful.

Ever since I found that ‘cheap’ Commodore 64 online I’ve been wanting to try something. The machine came with a tape drive, so I ordered some ‘cheap’ reproduction tape game, to see if it worked.

While it almost works, it sees the program on the tape, the thing stalls out. Granted it being dated to 1991 probably means the belts are beyond usable. I am having a friend proxy some belts for me as nobody will ship them to Hong Kong (pandemic didn’t have any real effect there).

While this machine is a newer ‘C’ model, I’ve had seen this auction pop on and off on Ebay from time to time advertising a refactored and improved CP/M cart advertising that it works on all models. I’ve read somewhere that post 128 that they finally had figured it out, far too late to matter. But maybe with this new cartridge things could work?

I managed to get a SD2IEC board delivered from Germany, which uses external USB power, so it won’t tax the C64 PSU (I should look, is there an ATX to C64 PSU?). I can load some silly games and stuff seemingly okay. I haven’t bothered with GEOS, as I used it far too much when I had to, and it’s just far too slow to even dream of being usable. Anyways with the SD2IEC it came with ZERO instructions but I did find the page with the needed firmware, and the ‘FB64.PRG’ program to have it browse the SD card and mound D64 images as needed.

I have to admit, ever since I did that article about “Running CP/M on the Commodore 64” I’ve been dying to try this on real hardware. With all the excitement in the room, I mounted the CP/M disk, and held my breath as the *’s went across the screen….

And, well something isn’t right. I tried a bunch of images I could find online, and they all do the same thing. They print far too many characters on the screen from time to time. Clearly it’s some timing/IRQ issue. Something to do with the VIC chip.

Despite the screen being corrupt, it is running, and it does let you run commands, it’s just the output is being doubled (or 10x!) up.

So I tried the soft80 program which will setup an 80 column CP/M experience. It didn’t matter what version I used, the old one from the 80’s or the patched up one from Luis Antoniosi, they all do the same thing, which is run at a blistering 1cps.

I thought it’d be fun to stream this old beast playing the CP/M version of planetfall, but at 1cps I just can’t do it. Which is just a shame. I haven’t tried a regular C64 Infocom game, as the 40 cols was always crazy, but I guess it’s the fallback.

I know these things are so rare, but I had high hopes for this thing.

So close, and yet so far away.