Re: IIgs ROM 01 & Z80+

["Michael J. Mahon" <mjmahon@aol.com>]

On 10/3/2010 10:31 PM, KP wrote:
> I have a Z80+ card in Slot 4 of my IIgs ROM 01.
>
> When I use it solely as "Your Card," it works.
>
> I then switch to "Mouse Port" for a GS/OS application, reset, run the
> application, and the mouse works fine.
>
> I then switch to "Your Card," reset, boot a CP/AM disk (either 5.1.1
> or 4), and CP/AM doesn't properly function.
>
> Turning off the IIgs and then turning it back on does not fix the
> problem; the Z80+ and/or CP/AM continue to malfunction.
>
> Opening the IIgs, re-seating the card, and re-booting the machine set
> to "Your Card," and I get another successful use of the Z80+/CP/AM.
> But as soon as I temporarily switch it to Mouse and then back again, I
> get the same problem.
>
> Does this sound like anything familiar to anyone on here?  I am going
> out of my mind trying to figure out what I need to do to permanently
> fix this.

This is very weird.

There is no mechanism by which either the card or the IIgs can remember
what happened prior to a power cycle that would be thwarted by removing
and re-seating the card.

I suspect that waiting several seconds between power-off and power-on
will produce the same result.

My hypothesis is that /RESET is not resetting everything on the Z80+
card, but waiting for the capacitors to discharge will result in a
complete reset on power-on.

-michael

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