Re: Zip GSX - Troubleshooting

[Toinet <antoine.vignau@laposte.net>]

On 6 nov, 06:36, Hugh Hood <hughh...@earthlink.net> wrote:
> Fellas,
>
> I could use a little help troubleshooting a backup Zip GSX card that I
> bought used installed in a ROM 3 IIgs.
>
> The card appears to work fine with _one_ exception -- When it is installed I
> cannot enter the Desk Manager (Desk Accessories/CDA Menu) using the
> command-control-escape keyboard sequence.
>
> As you know, when that key sequence is entered, (provided interrupts are not
> disabled) the ADB controller sends an interrupt that is identified and then
> the Desk Manager routine is initiated.
>
> For some reason, the CPU on the Zip GSX is either not receiving the
> interrupt, is ignoring it, or is not able to access the Desk Manager vector.
>
> Here's what I've tried:
>
> 1. Remove Zip GSX and re-install original 65C816 - Desk Manager IS
> accessible. (So, the computer and keyboard are functioning fine).
>
> 2. Re-install Zip GSX and re-seat Zip GSX cable and ensure all pins are
> inserted correctly - Desk Manager is NOT accessible.
>
> 3. Enter the monitor and run short program to clear the interrupt disable
> flag (CLI - 58) - Desk Manager is still NOT accessible.
>
> 4. Ensured that the S1 (Control Panel Disable) Jumper is not jumpered on the
> ROM 3 motherboard - Desk Manager is NOT accessible. <BTW, this jumper may
> just disable control panel access, not the CDA menu>.
>
> So, what's left - bad CPU, bad cable, broken trace? Other than this issue,
> everything else seems fine with the Zip GSX. I'm stumped.
>
> Has anybody here experienced this before or perhaps can shed some light on
> what is happening?
>
> Thanks.
>
> Hugh Hood

IIRC there is an alternative key sequence to enter the control panel
on a ROM 03.

Did you try it?

antoine