RedskullDC wrote:
"mojoehand" <jgray@zianet.com> wrote in message 11342068-9a14-427c-bbf8-7915b2866614@q26g2000prq.googlegroups.com">news:11342068-9a14-427c-bbf8-7915b2866614@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