Old Mac drive blows GS? (was Re: GS Diagnostic Codes?)

[Rubywand <rubywand@swbell.net>]

gsentlinger writes ...
> 
>         I'm having trouble with my apple iigs rom 1. I plugged something I
> shouldn't have (an old mac 800k drive) into its drive interface. It broke
> it. When I boot up, it gives me the intro screen and a beep. I can't get
> into the control panel and when I pushg ctrl reset, it doesn't give me a
> prompt, it only refreshes the intro screen and beeps. Other than that it's
> locked up. I feel really bad that I wrecked my computer.
>
>         When I run the self-test, It finishes with this number printed 
> three times
> in the upper left corner "06010000" and at the bottom it says "system bad
> 06010000" ....
>

     It is unlikely that the reported error is related to your disk I/O 
problems. As has already been observed, "06010000" indicates that the 
self-test routine believes that there is a problem with R/W to a register on 
the serial controller IC-- the SCC.

     A check of the GS (ROM-01) schematic indicates that the SCC has no lines 
going to the disk port-- the interface IC for the disk port is the IWM chip. 
Also, the SCC appears to depend upon no outputs from the IWM.

     Plugging in an old Mac disk drive should have no effect on the SCC. 
Perhaps, as Nathan suggests, the error is a false report due to some 
peripheral such as an accelerator card.

     So, do you have a blown IWM? Without knowing the pinout of the old Mac 
disk drive it is difficult to say anything much about how likely a blown IWM 
might be. One person likely to know something about old Mac drives is 
Steve Buggie; or, perhaps a Mac user could supply old 3.5" drive pinout 
information.

     With luck, you may have blown one of the power line traces going to the 
disk port socket. Another possibility is that a soldered socket connection 
was worked loose when the Mac drive was plugged in. (One check for the latter 
situation is to plug in your standard Apple 3.5" drive and wiggle the 
connecter slightly and, then, try powering-up.) It would, also, be 
interesting to find out whether or not you can boot from a 5.25" drive 
connected to the disk port.


Rubywand