Subject: Re: Msoft Softcard (softswitch?)
From: nparker@ssil.uoregon.edu (Neil Parker)
Date: Wed, Oct 21, 1998 716
Message-id: <70m4hn$1fc$1@pith.uoregon.edu>

In article <19981021135249.24555.00002407@ng57.aol.com>,
DougKalley <dougkalley@aol.com> wrote:
>
>I finally picked up a softcard to go with all these disks for it I have had for
>years. Pretty cool, except after playing around and doing a little research I
>found out I need activate a softswitch to get to the Z80. Anybody know the poke
>or call the flip the card on? 

There were at least three different incompatible things called "Microsoft
Softcard"--the original Softcard (a standard slot card with just a Z80 and
some standard logic chips, and four DIP switches), the Premium Softcard IIe
(an auxiliary slot card for the IIe, which doubles as an 80-column 64K card),
and the CATS Softcard (about which I know nothing, except that it's
different from the other two).

If you have the original Softcard, the Z80 is activated by writing to any
address in the slot ROM space ($Cn00-$CnFF, where "n" is the slot number).
This immediately suspends the 6502 and starts executing Z80 code at memory
location $1000 (which the Softcard remaps to Z80 memory location 0), so
there had better be actual Z80 code at that location.

A second write to the slot ROM space suspends the Z80 and resumes the 6502
at the location where it left off.  Subsequent writes to the slot ROM space
toggle between the 6502 and the Z80, with each resuming at the location
where it was previously suspended.

If your Softcard is in a IIGS, make sure the system speed is set to "slow".
The Z80 won't activate if the speed is fast.  (And, of course, make sure
the slot is set to "Your card".  The Softcard is happiest in slot 4.)

Apparently the other Softcard versions are controlled by different means.
I don't know how to control the other versions.


If your CP/M boot disks are refusing to boot, then something is wrong.  The
original Softcard boot is completely transparent--just stick the disk in
the drive and turn the machine on, or press control-reset, or type "PR#6".
You don't need to do anything to manually activate the card.

(You do, however, need to make sure the DIP switches are set correctly.  On
the original Softcard, all four switches should be off.)

               - Neil Parker
-- 
Neil Parker, nparker@ssil.uoregon.edu, nparker@axis.llx.com,
http://axis.llx.com/~nparker/     (Note new addresses and home page!)

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