jcg852@anu.oz.au (John C Gallant) (02/18/91)
I have an A500 with A501, 1.2 ROMs and WB 1.2 and 1.3, modem on serial port and printer on parallel. I recently found that the system clock is not running (it used to!). More specifically, I can set the system date and time using 'setclock opt load' from the battery-backed clock, and the time is set ok, but the time doesn't advance from then on. I wrote a short C program to read the system clock using the library call and found it was actually running but extremely slowly - like several hundred microseconds counted on the system clock for every second of real time. I know that the system clock is guaranteed to never return the same time twice, so I think this very slow running is due to various tasks asking for the time repeatedly. It doesn't matter whether I use WB 1.2 or 1.3. The documentation I have doesn't explain how the system clock is run, so I'm not sure where to start looking for problems. I'd like some info on how the system clock works and any ideas on where to look for my problem. FYI, I'm an electronic engineer and programmer but without much in the way of test equipment available to me. Feel free to be as technical as you need to be. Please send mail (if you can) and if there is enough interest I will post a sumary and (hopefully!) notes on the repair. Thanks a bundle John Gallant jcg852@csc.anu.oz.au
mikep@hpmwtd.HP.COM (Mike Powell) (02/20/91)
Try swapping your CIA's (8520 is the chip number I *think*)... the CIA's handle many system timing issues.... swapping the chips should move the problem.... if so, then you'll need a new CIA. I think they are about $40 or less... -Mike-
erk@americ.UUCP (Erick Parsons) (02/24/91)
>In article <7849@jcsneuro> jcg852@anu.oz.au (John C Gallant) writes: >I have an A500 with A501, 1.2 ROMs and WB 1.2 and 1.3, modem on serial >port and printer on parallel. I recently found that the system clock >is not running (it used to!). More specifically, I can set the system >date and time using 'setclock opt load' from the battery-backed clock, >and the time is set ok, but the time doesn't advance from then on. I Sounds like you need an 8520. I blew up several of these getting my Epson LX-810 to work (power cycling the printer did the nasty deed). To get the Par: port back I swapped the two 8520's and found that my clock went dead, just like yours. Lesee... (quick look at the schems) Looks like U7 is the culprit. Try swapping them first and see if the problem migrates. -- -------------------------------------------------//------------------------- (ames att sun)!pacbell! ----> sactoh0!pacengr!americ!erk Multitasking, ucbvax!ucdavis!csusac! --/ // Never leave uunet!msac! -/ Erick Parsons \Sacramento Ca Home Without it --------------------------------------------\X/----------------------------- Please Don't Wait...
chuckt@theborg.mlb.fl.us (Chuck Teschke) (02/27/91)
I had a strange problem with my 8520's, sometime when i would click on icons
in workbench my system would completely lock up. but if i pulled a disk out of
either df0 or 1 and then put it back in the system would read in the disk and
unfreeze. also my clock was messing up constantly. so i switched my 8520's and
when i booted i just got a yellow screen and it didnt boot. so i put new ones
in and everything has worked fine ever since.
Chuck Teschke
chuckt@theborg.mlb.fl.us