ridder@elvira.enet.dec.com (Hans Ridder) (02/21/90)
I recently had a problem with an A500. After booting the Workbench, you could click and open the RAM icon, but if you clicked on the Workbench disk icon, the system would hang (the pointer would freeze after the first click). A few seconds later the power light would do the blink routine, but the system would not re-boot. A three fingered salute would get the blinks and then hang again. You'd never get the actual "guru". After cycling power, you could re-boot. This was totally 100% re-producable. Even tried different workbench disks - same problem. To make a long story short, after swapping everything but the key caps, I finally swapped Paula. That fixed it. This puzzles me. I know she does the ports, disk data, and the interrupts. The only thing that I could think of was that she was corrupting the disk data. However, if there were the case, I would think that the checksums would fail, and I wouldn't have been able to boot. Not to mention, all the way to a workbench screen! How is it that Paula would allow the system to boot, but fail on the first click of the disk icon? Any ideas? Commodore people? -hans ======================================================================== Hans-Gabriel Ridder Digital Equipment Corporation ridder@elvira.enet.dec.com Customer Support Center ...decwrl!elvira.enet!ridder Colorado Springs, CO
p554mve@mpirbn.UUCP (Michael van Elst) (02/23/90)
In article <736@shodha.dec.com> ridder@elvira.enet.dec.com (Hans Ridder) writes: >How is it that Paula would allow the system to boot, but fail on the >first click of the disk icon? Any ideas? Commodore people? An identical symptom showed up on my Amiga, yet it wasn't Paula but one of the CIAs. Nevertheless, the reason for this behaviour is the interrupt system, and this is managed by Paula AND the CIAs. The problem arises from the attempt to synchronize rendering with the electon beam in you monitor. One CIA clock is used to time the interrupt routine excactly to the correct scanline and Paula of course delivers the interrupt. Now on the ususal workbench screen the synchronisation is used only with icon movement. (I've played with the old Kick1.1, and everthing works there because only the pointer changes when moving an icon). Michael van Elst uunet!unido!mpirbn!p554mve