Very nice! If you want to submit your configurations for the 1541 to the repository so others can try it out, please send me a PR or email me the csv files.
Fascinating project - a really nice hardware+software solution. I had a question about the pull-up fix you made please. When you enabled the pull-up resistors in the FPGA to fix the DIP read issues with the new board, did the fixed code still work on the old boards that didn't have the issue?
Good question - yes, I did try the fixed code on the old boards, and they still worked fine. Very strange issue - everything is completely identical except the PCB provider and where I had them assembled. I would have to guess something like a slight difference in the copper traces between the two batches, which leads to the old batch having enough of a pullup effect to make reading the switches work while the new batch does not. Also tried the new code on a couple of boards from the original batch which I had thought were bad but never spent the time to look into why - and those now work as well.
I own some old synths which uses a Z80 and have soldered ROM chips on thier PCBs may your Z80 board is an elegant way to replace these with a newer version and bypass the original ROM chips. I don't want to try to desolder these original ROM chips out of the synth because A) old B) huge... I would need to strip the synth almost entirely to get that one big PCB out and then try to desolder the two ROM chips and also may damage traces... Even though I own professional desoldering tools, I'm always in fear that I damage an old PCB and then need to re-trace it...also it's a 4-layer which uses power and ground in the middle layers and this makes desoldering even more difficult... So your board is an elegant and future proof. Because I also can replace the original ROM patches. And, with enough spare time I even could re-write that buggy midi part which causes the machine to crash every time I send some unknown stuff to it because it's always in midi omni. When I studied EE, we had to program Z80 boards in assembler...therefore, this should be doable. Thank you for doing these boards. Cheers, TC
Great, let me know how it works for you! One note on the ROMulator in the Apple II - because of the position/orientation of the 6502 on the apple II board, the ROMulator board sits slightly too low and intersects some of the card slots. Best to use another 40-pin dip socket on the bottom to raise it up slightly to have it clear the connectors.
I used my 6502 Romulator to develop a wifi addon for my 1541 and worked flawlessly even wih the old bitstream.
Very nice! If you want to submit your configurations for the 1541 to the repository so others can try it out, please send me a PR or email me the csv files.
I held my breath with you through that one. I’ve got a v1 board that works like a champ. Glad this new batch is all set for you!
It’s always the smallest of things that mess you up, in this case a single bit :)
Fascinating project - a really nice hardware+software solution. I had a question about the pull-up fix you made please. When you enabled the pull-up resistors in the FPGA to fix the DIP read issues with the new board, did the fixed code still work on the old boards that didn't have the issue?
Good question - yes, I did try the fixed code on the old boards, and they still worked fine. Very strange issue - everything is completely identical except the PCB provider and where I had them assembled. I would have to guess something like a slight difference in the copper traces between the two batches, which leads to the old batch having enough of a pullup effect to make reading the switches work while the new batch does not. Also tried the new code on a couple of boards from the original batch which I had thought were bad but never spent the time to look into why - and those now work as well.
Strange. I never had an issue with the reading of the DIP switches on my v1.05 board either.
I own some old synths which uses a Z80 and have soldered ROM chips on thier PCBs may your Z80 board is an elegant way to replace these with a newer version and bypass the original ROM chips.
I don't want to try to desolder these original ROM chips out of the synth because
A) old
B) huge... I would need to strip the synth almost entirely to get that one big PCB out and then try to desolder the two ROM chips and also may damage traces... Even though I own professional desoldering tools, I'm always in fear that I damage an old PCB and then need to re-trace it...also it's a 4-layer which uses power and ground in the middle layers and this makes desoldering even more difficult...
So your board is an elegant and future proof. Because I also can replace the original ROM patches.
And, with enough spare time I even could re-write that buggy midi part which causes the machine to crash every time I send some unknown stuff to it because it's always in midi omni.
When I studied EE, we had to program Z80 boards in assembler...therefore, this should be doable.
Thank you for doing these boards.
Cheers,
TC
Excellent wo4k amd video! Love the new way to set up the settings
Just got mine, looking forward to using it to fix my apple 2 clone!
Great, let me know how it works for you! One note on the ROMulator in the Apple II - because of the position/orientation of the 6502 on the apple II board, the ROMulator board sits slightly too low and intersects some of the card slots. Best to use another 40-pin dip socket on the bottom to raise it up slightly to have it clear the connectors.
Also plan to have a little extension board/cable available shortly so you can relocate the ROMulator to a more convenient position.
I wonder "How did it ever work" /WHILE/ my things are working. can relate.