dillon@ucbvax.ARPA (The Sherif "Matt D.") (02/11/85)
I would like to compile a list of all the known errors in the commodore 64 roms (NOT THE 1541 ROMS, PLEASE). I'll start off with what I know: (Older C64's) 'Clear' color set inproperly so that Pokes to the screen come in as background color. Yields nothing visible unless color memory is also poked. (All C64's.. I think) Bug in cursor editting.. When inserting on last line or something like that. RS-232 problems. Basically, the RS-232 routines are a bunch of crap, and should be completely re-written. They don't work above 1200 baud in terms of being reliable (I certainly would not trust them). Hardware error on the CIA's.. The CIA fails to catch interrupts sometimes when your using Timer B. Folks, Commodore got around this one by using one timer on each chip. Unfortunetly, it doesn't solve the problem. I had an interrupt driven routine that used Timer B as a one-shot, and reset it. Every once in a while, Timer B simply never issued an interrupt. Bryce did some experimenting, and found that the problem seemed to occur when timers A & B timed out within a couple of clock cycles of each other. And, of course, all the kernal routines were written in JOE-CODE (We wont mention the DISK OS... That's worse). Anything else? Matt "Only saw 'GUNSMOKE' once" Dillon.
doug@terak.UUCP (Doug Pardee) (02/12/85)
> I would like to compile a list of all the known errors in the commodore 64 > roms (NOT THE 1541 ROMS, PLEASE). A non-ROM error -- some (or maybe all) of the CIA's do not give correct Time-Of-Day results. (Yes, I know the registers are BCD, not binary, mine still runs at ~2.5 times correct speed). This isn't used by any software I know of, but probably explains the reason that the system time is kept by a software clock which can be, and is, disrupted by I/O activity. Also: since joystick 1 is normally in parallel with the keyboard, holding it left (?) is the same as holding the CTRL key, causing the program to slow way down. This can really disrupt a game! -- Doug Pardee -- Terak Corp. -- !{hao,ihnp4,decvax}!noao!terak!doug