Denial

Wilson wrote: ↑Mon May 05, 2025 4:39 pm The color RAM is only 4-bit. What you read on the upper 4 bits will just be garbage on the bus.
You need to AND your read value with $0f to get the actual contents of the memory between $9400-$9800.

Oh, is it that simple? Hehe. Of course - that makes perfect sense now. Thanks for that

I've noticed that if I try to do a PEEK(38400), I don't always get the actual colour value back - and I see the same thing in VICE (unexpanded Vic). When the kernel scrolls the screen up (as it would during a LIST for example), I assume that the the kernel must read the colour RAM in order to move t...

Orangeman96 wrote: ↑Wed Apr 16, 2025 7:43 pm Good luck, SparkyNZ! -OGM

Thanks - the PCBs arrived today.. Just populated a board.. and it works!

You really should use a 74LS00 and do /OE = /(CR/W & SΦ2) - as I already wrote, CR/W on its own has the wrong timing. My v2 PCBs arrived today. Cartridge/ROM images started straight away. RAM bank switching also working. Happy chappy :-) Now I'll have to get back to the reason I went down this ...

Just an update since I went pretty quiet (and busy). I'm still waiting for my new cartridge PCB arrive but I did manage to get a BASIC program to autostart within Vice using a (raw) .crt image.. so thanks for all the help. I'll should be able to test this out on the real thing in the next few days.

groepaz wrote: ↑Sat Apr 05, 2025 9:00 am I'll add a warning to cartconv for this case NOW. i can see how its a stumbling block

Excellent, thank you - and noted. It doesn't take much to make me stumble

I may have a 74LS04 floating around if I'm lucky. You really should use a 74LS00 and do /OE = /(CR/W & SΦ2) - as I already wrote, CR/W on its own has the wrong timing. Thankfully I do have some old 74LS00 chips. I haven't had time to fiddle about with bread/protoboards this weekend but I did fi...

What is the EPROM's A13 connected to? If you used CA13 on the expansion port, that's wrong. BLK5 only covers 8 KB, and only the address lines CA0 to CA12 are necessary to address the whole contents of BLK5. CA13 happens to be 1 within BLK5, and your cartridge hardware then addresses $2000..$3FFF wi...

via the autostart procedure of VICE. Attaching as cartridge strictly means going through the "File > Attach cartridge ..." menu, selecting a file there, and before that, (probably) specifying to VICE where the file should be attached to a write-only(!) memory dump. .. So, what precise act...

Hmm. So I have 2 AT28C256 (32K ROM) with A14 tied to GND. I loaded both my image and the Choplifter image onto each ROM. When I try a PEEK(40960) I would have hoped to have seen either $0F or $09. Unfortunately I'm seeing $FF. I have: /BLK5 signal connected to /CE on the ROM. /CE is also connected t...

I finally got it working! :-) I guess I'm using "old" .crt format here since I have no header. I had to do a few things: 1) Assemble with CBMPrgStudio -> .prg file 2) Remove the 2-byte header from the .prg file, resulting file is .raw file 3) Pad the .raw file up to 8k 4) Rename .raw to .c...

Uh. The Problem is your ancient VICE. You absolutely have to use 3.9 for proper crt support in xvic I have been trying the .crt on different versions of Vice - the ancient one and this (latest) GTK one: GTKVice.png I can't get it to work - below is with the "Smart" options: GTK_fail-1.png...

Mike wrote: ↑Fri Apr 04, 2025 3:14 am When you have attached the *.crt file in VICE, does the chip content even show up in BLK5 when you invoke the monitor?

This doesn't look good does it? It looks as though it isn't parsing the .crt header and actually loading the file like a raw file. I'll sleep on it..

I've also tried padding the input files up to 8192 bytes. This now produces no errors/warnings in both cartconv or Vice when I try to load the .crt file but the cartridge isn't auto starting?? From bin file (no 2-byte header): W:\Vic20Dev\VicRom1>cartconv -t vic20 -i bin.pad -o VicRom1.crt -l a000 I...

OK, so now that I have the "load PRG into BLK5" method working - how can I create a .crt file with cartconv? Is the input file supposed to be .prg or just raw binary (no 2-byte header) ? W:\Vic20Dev\VicRom1>cartconv -p -t vic20 -i VicRom1.bin -o VicRom1.crt -l a000 Error: Can't read VicRom...