RedskullDC wrote:
> 
> "mojoehand"  wrote in message 
> news:11342068-9a14-427c-bbf8-7915b2866614{at}q26g2000prq.googlegroups.com...
>> I just tried a Z-Card in a ROM3 IIgs and even at slow speed, it won't
>> boot CP/M. It starts to boot and hangs. It works fine in my IIe. Not a
>> huge problem, but I am curious as to why it won't work in a IIgs.
> 
> Will take a wild stab and say probably the Z-Card flavour of CP/M
> doesn't take care of/turn off the 65816 interrupts before it switches
> to Z80 mode.

I'll guarantee that the Microsoft variants of CP/M for the Softcard knew 
nothing about a 65816.  In fact, both versions of Softcard CP/M preceeded the 
65C02!

It's more likely to be a slight difference in timing margin that pushes it in 
the wrong direction to cooperate on the IIGS bus.  Depending upon how much 
time the original poster has on their hands, it might respond to playing 
musical chips (replace things one at a time with faster parts or ones capable 
of higher fanout).

Steve
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