Re: IIgs ROM 01 & Z80+

[KP <kjpmail@gmail.com>]

On Oct 5, 8:00 am, Steven Hirsch <snhir...@gmail.com> wrote:
> On 10/04/2010 11:20 PM, Michael J. Mahon wrote:
>
> >> A TransWarp as in Apple 2e? I seriously doubt that will work. The Z80
> >> card shares motherboard memory with the system CPU by stopping the 6502
> >> (ISTR this is via INH\, but that may not be correct). At any rate, the
> >> IIe TransWarp does exactly the same thing on a permanent basis so they
> >> are not going to coexist very well.
>
> > I think it uses the /RDY line to halt the 6502. That's one reason that
> > it won't work with a Zip Chip.
>
> Thanks for keeping me honest.  I'm not really a hardware guy and don't keep
> this stuff in my forebrain :-).
>
> >> Tony mentioned the need to run at 1Mhz. in another posting. That's a
> >> hard requirement for proper functioning of a SoftCard style coprocessor.
> >> It truly was a bit of a hardware hack. I have three or four SoftCards
> >> and perhaps a half dozen AE Z80+ cards. Some will work in some systems.
> >> None of them will work in all of my systems. One more reason to keep on
> >> the lookout for an Applicard if you're serious about Apple CP/M. Never
> >> found a box that an Applicard wouldn't work in and it coexists with any
> >> and all accelerators on both IIe and IIgs - at high speed settings, too.
>
> > All the "Softcard-derived" Z80 cards used a syncopated 3.5MHz clock,
> > which was regarded even at the time as a major hack. Like some other
> > cards, it has tight bus timing margins, and so running it on a system
> > other than one it was tested in during design is actually running a
> > reliability test. ;-)

So is the final verdict on this that the card should work on a //e but
it's no surprise if it doesn't work on a IIgs ROM 01 (even at 1 mHz)?
Or should I be concerned that the card is defective?