Re: Dos CP/M on a Z80 card require an 80 column card to work?

["Bill Garber" <willy46pa@comcast.net>]

"Michael J. Mahon" <mjmahon@aol.com> wrote in message
20030920193435.17721.00001182@mb-m01.aol.com">news:20030920193435.17721.00001182@mb-m01.aol.com...
> Paul Schlyter wrote:
>
> >In article <qwmdnfRJt9A_5_aiU-KYuQ@comcast.com>,
> >Bill Garber <willy46pa@comcast.net> wrote:
> >From: "Bill Garber" <willy46pa@comcast.net>
> >Subject: Re: Dos CP/M on a Z80 card require an 80 column card to work?
> >
> >> "Paul Schlyter" <pausch@saaf.se> wrote in message
> >> news:bkfqoi$s9q$1@merope.saaf.se...
> >>
> >>> The dip switches on the Z80 card may have been set improperly -- all
> >>> 4 of them should be set to the OFF position to run Apple CP/M.
> >>
> >> Come to think of that. I do need switch 4 set to ON to run it
> >> with my 80 column card in place. Sorry that I didn't remember
> >> that part.
> >
> >Strange --- my Z80 Softcard always worked with an 80-column card with
> >all the 4 Softcard dip switches set to OFF.  It's a Microsoft
> >Softcard, and the 80-column card was a Videx card.
>
> According to information on the web:
>
> "If your card is a Microsoft Softcard (easily identifiable by the words
> "MICROSOFT SOFTCARD" printed in the upper left corner of the component
> side), or a clone thereof, then OFF is the correct position for all four
> switches (Softcard CP/M doesn't use any of the features that the switches
> control).
>
> The Softcard switch settings are as follows:
>
> Switch 1:  OFF = Address translation occurs (Z80 address 0000H corresponds
>                  to 6502 address $1000)
>            ON =  No address translation (Z80 address = 6502 address)
>
> Switch 2:  OFF = Softcard locks out all other DMA devices when Z80 is
active
>            ON =  DMA signal from higher slot can interrupt Softcard
>
> Switch 3:  OFF = Softcard ignores NMI
>            ON =  NMI causes Z80 non-maskable interrupt
>
> Switch 4:  OFF = Softcard ignores IRQ
>            ON =  IRQ causes Z80 interrupt
>
> Softcard CP/M expects to find addresses remapped, so switch 1 should be
> left off.  Most Softcard CP/M programs can't handle interrupts, so
switches
> 3 and 4 should be left off too.  Turning switch 2 on probably won't hurt
> CP/M, but leaving it off is consistant with CP/M's philosophy of letting
> the 6502 handle most I/O."
>
> So all switches should be off.

With switch 4 off, all my CP/M cards light up and
nothing further will take place. It simply sits there
and waits.

Bill @ GarberStreet Enterprizez };-)
Web Site - http://garberstreet.netfirms.com
Email - willy4SPAM6pa@comXcast.net
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