4 ms·
> Also, they got more capacity, but did they also get at least the same speed and reliability? 1541 was horribly slow because the marketing people wanted it to
by selcuka 3y ago
> Also, they got more capacity, but did they also get at least the same speed and reliability?
1541 was horribly slow because the marketing people wanted it to be backwards compatible with VIC-20, and the serial protocol used by the VIC-20 was very slow because of a timing bug found at the last minute. It was possible to multiply the default speed by an order of magnitude or more using custom firmware, but stock software was almost slower than using a cassette tape.
- taylorportman 3y agoThere was a trimmer potentiometer one could adjust until errors would occur and then turn back just a little that would result in a speed increase. It may have been the motor speed I can't remember.
- actionfromafar 3y agoWasn’t that the cassette head alignment?
- selcuka 3y agoYeah, they are probably remembering the azimuth adjustment screw on a cassette player.
- EvanAnderson 3y agoCompatibility with the shift register in the VIC-20 CIA was a part of it, but Commodore had a “fix” that was removed from the board during a revision that would have resulted in fast serial transfers from the 1541 on a C-64. Finding primary sources while on my phone is difficult, but there’s some discussion here that would probably point you to a primary source. (Bill Herd and other have spoken about it in panels at various VCF gatherings.) https://www.lemon64.com/forum/viewtopic.php?t=58317 https://www.lemon64.com/forum/viewtopic.php?t=58317
- selcuka 3y agoOoh, I didn't know this detail. Thanks. It sounds terrifying: > It also had something to do with a board screw hole. Iirc, the pcb already had a screwhole where the traces should be. Robert Russell was the engineer who designed those IEC traces and so when he found out about it, he was pretty much upset, but it was too late, they already modified thousands of boards.