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Re: Microsoft Premium Softcard //e doesn't fit in my Apple //e!

On Wed, 20 Feb 2013, Michael J. Mahon wrote:


Steven Hirsch <snhirsch@gmail.com> wrote:

On 02/20/2013 09:47 AM, gids.rs@sasktel.net wrote:



   I have one of my Freed clones running at 20Mhz :-).



Yeah, Steve.  I recall that Jim Lill posted some instructions on the old
GEnie site for getting the card to run at 9 mHz.  I followed them, and it
ran at 9 mHz without a hitch.  (Probably still does.  I should be able to
check that out in a couple of months after I resuscitate some other
things.)  In addition to the crystal change, the card had to be
repopulated with the F version of the several chips.



Has anyone ever tried upgrading a Z80+  with its far fewer chips?

http://apple2info.net/index.php?title=Z-80_Plus


Unfortunately, the architecture of the traditional Softcard (of which the
Z80+ is a knockoff) dictates the CPU clock (which is derived from the
motherboard rather than an on-board oscillator).  Not much to be done about it.


I remember its clever "syncopated" clock even got a write up in EDN at the
time.

-michael - NadaNet 3.1 and AppleCrate II: http://home.comcast.net/~mjmahon
I wonder how possible it would be to make a card like the SoftCard that gives the Z80 twice as many cycles before handing off to the 6502. 

-uso.