grr@cbmvax.UUCP (George Robbins) (07/31/87)
In article <5162@utcsri.UUCP> flaps@utcsri.UUCP (Alan J Rosenthal) writes: > > I've crashed my Amiga really thoroughly and found Ctrl-Amiga-Amiga still to > work. Is it implemented at a hardware level to any extent, or what? How > does it work? In the A1000 and A2000, the Control-Amiga-Amiga reset works as follows: The keyboard microprocessor (ROM based) senses the key combination. It sends a "warning" keycode to the CPU... I don't think AmigaDOS does anythign special... It jams the keyboard clock line low... Hardware on the CPU board times out the clock line... And asserts reset and halt on the 68000... Thats all she wrote. In the A500, a logic gate in the keyboard detects the key combination and asserts reset directly. They keyboard micro would still like to send its keycode and whatnot, but never gets a chance. So anyway, the system does do a hard, unavoidable, reset when you hit the C-A-A key combination. There are however some things in the software that try to recover the contents of memory after a reset that could conceivably puke and die if some areas of memory looked good, but were actually corrupt. -- George Robbins - now working for, uucp: {ihnp4|seismo|rutgers}!cbmvax!grr but no way officially representing arpa: cbmvax!grr@seismo.css.GOV Commodore, Engineering Department fone: 215-431-9255 (only by moonlite)
scotty@l5comp.UUCP (Scott Turner) (08/08/87)
In article <2171@cbmvax.UUCP> grr@cbmvax.UUCP (George Robbins) writes: >the C-A-A key combination. There are however some things in the software >that try to recover the contents of memory after a reset that could >conceivably puke and die if some areas of memory looked good, but were But if you store "HELP" into the longword at location 0 you don't have to worry about that. :) The reset handler in the ROM will see this and deliver the coup de grace without ANY chance of recovery. Scott Turner -- UUCP-stick: stride!l5comp!scotty | If you want to injure my goldfish just make UUCP-auto: scotty@l5comp.UUCP | sure I don't run up a vet bill. GEnie: JST | "The bombs drop in 5 minutes" R. Reagan "Pirated software? Just say *NO*!" S. Turner