Date   : Fri, 23 Sep 1988 18:36:00 GMT
From   : steinmetz!davidsen@itsgw.rpi.edu (William E. Davidsen Jr)
Subject: Z-80 Unix?

In article <704@tetra.NOSC.MIL> budden@tetra.nosc.mil.UUCP (Rex A. Buddenberg)
writes:

| 2.  What are implications for the follow-on Z-80 derivative chips
| like HD64180 and Z-280?  How portable are we here?  If you can make
| things work in a 64k RAM space, life ought to get easier if you can
| lay hands on more RAM...  Somehow sounds like an awkward fit though
| until you get hardware memory management to take a lot of the load off
| your code...muse,muse,muse.

  I hacked CP/M to live in an alternate memory bank (actually I ran it
in the 2nd bank and had a faker in the main memory). Using that
technique you could get more memory for UNIX and possibly run a lot more
of it. That would allow you to have multiple processes, too, since there
would be virtually no swap overhead. I don't know about i/o, I can't
think of any *cheap* way to do it into an unselected bank.
-- 
       bill davidsen           (wedu@ge-crd.arpa)
  {uunet | philabs}!steinmetz!crdos1!davidsen
"Stupidity, like virtue, is its own reward" -me


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