[rich82fox]

hi

two powermac g3 beige desktop units I have won't start up

when I switch it on - it begins to boot up and then a white dialogue box comes up saying "Bus error" and the option to restart

the same thing occurs when booting from a CD - I've tried zapping the pram with no luck

anybody have any ideas what could cause buss errors?

rich

[Lateralus]

Try yanking some RAM. Bad RAM is what usually causes me bus errors in OS 9.

[P]

Bus error means that the CPU tried to do something with a memory address that does not exists - say a byte with an address of 1 gig when you only have half a gig installed. This usually happens because the system is running random code - it has jumped off track and reading data as code - but if you get it when starting from a CD it can be a hardware fault. RAM is a good place to start when trying to find hardware faults - it could be a softflip, or a RAM chip that reports itself as active at boot but then fails, reducing the available RAM.