[sebhc] Z-100 upgrade modules (ZMAX memory upgrade and ZCLK clock) available

Dan Lanciani ddl-cctech at danlan.com
Sat Apr 15 15:09:06 CDT 2006

|The newer machines, of course, natively supported 768 megs of memory (3
|banks of 256).  To change from 3 banks of 64 to 3 banks of 256 all you
|needed to do was change a PAL or two.  The newer machines also supported an
|8MHz 8088 instead of the 5MHz part that most machines shipped with.

I had one of the earlier mother boards.  I replaced the 8088 with an 8MHz
V20, but the fastest I could get it to run reliably was around 7.2MHz.
I never looked for the bottleneck.

|was a formal upgrade kit from Heath that included all of the parts required
|to do both modifications.  No cuts or jumpers were required, just chip
|changes.  Which makes me question the point of ZMAX, since it only worked on
|the later (2806) motherboards.

That's what I was wondering as well.  Even on the older mother boards you
only needed to change one PAL (if you wanted to he really neat) or raise
the pin on the existing PAL.   I can't remember having to cut any traces
(just add the jumpers) but it was a long time ago...

				Dan Lanciani
				ddl at danlan.*com

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