Date   : Tue, 01 Mar 1988 11:31:00 EST
From   : RLH <"RCVAXB::HAAR%gmr.com"@RELAY.CS.NET>
Subject: query - S-100 CPU upgrade boards

I want to upgrade my S-100 bus CP/M system with a CPU board using
one of the new Z80 replacement chips. What board-level products
are available? Can anyone give recommendations and/or comparisons?

Since I want to maintain Z80 and CP/M compatibility, I am interested
in the Hitachi HD64180 and the Zilog Z180 & Z280 chips to get the
larger address space. I also want to be able to move up to ZCPR
when the versions supporting these chips become available.

My configuration is pretty much normal for hobbyist S-100 CP/M systems:

    Tarbell Z-80 CPU card with banked memory and serial I/O
    Tarbell floppy disk controller with 8 " SSDD drives
    192K static RAM
    SDS VDB8024 video display & keyboard interface board
    misc. serial/parallel I/O and clock/calendar boards

    CP/M Plus (v 3.0) in banked mode

I would like to replace the CPU board but keep everything else in place
to start with. I would be willing to add an external CRT terminal
and 5 1/4 floppies if that makes sense. Also, I have done enough
assembly language hacking on the BIOS that some of that is no
problem.

Since I suspect that others on this list have similar interests, I
suggest that responses be posted here rather than sent to me
directly.

            Bob Haar
            E-mail: HAAR@GMR.COM  (on CSNET or ARPANET)