Xref: utzoo comp.misc:3539 comp.sys.misc:1709 comp.os.cpm:1759
Path: utzoo!utgpu!attcan!uunet!steinmetz!davidsen
From: davidsen@steinmetz.ge.com (William E. Davidsen Jr)
Newsgroups: comp.misc,comp.sys.misc,comp.os.cpm
Subject: Re: Z-80 Unix?
Keywords: z-80 unix
Message-ID: <12207@steinmetz.ge.com>
Date: 23 Sep 88 18:36:00 GMT
References: <278@pte.UUCP> <6288@xanth.cs.odu.edu> <2906@mipos3.intel.com> <704@tetra.NOSC.MIL>
Reply-To: davidsen@crdos1.UUCP (bill davidsen)
Distribution: na
Organization: General Electric CRD, Schenectady, NY
Lines: 19

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