Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP
Path: utzoo!utgpu!water!watnot!watmath!clyde!rutgers!ames!ucbcad!ucbvax!sdcsvax!ucsdhub!jack!man!crash!mwilson
From: mwilson@crash.UUCP
Newsgroups: comp.os.cpm
Subject: Re: SUPRBDOS use of z80 registers?
Message-ID: <931@crash.CTS.COM>
Date: Sun, 22-Mar-87 02:57:16 EST
Article-I.D.: crash.931
Posted: Sun Mar 22 02:57:16 1987
Date-Received: Mon, 23-Mar-87 00:00:52 EST
References: <1987Mar19.141504.21625@gpu.utcs.toronto.edu> <15244@amdcad.UUCP>
Reply-To: mwilson@crash.CTS.COM (Marc Wilson)
Organization: Grossmont College, El Cajon, Ca.
Lines: 34

In article <15244@amdcad.UUCP> bandy@amdcad.UUCP (Andy Beals) writes:
>In article <1987Mar19.141504.21625@gpu.utcs.toronto.edu> edwest@gpu.utcs.toronto.edu (Dr. Edmund West) writes:
>>  Incidentally, I got started on all this when I tried to install
>>SUPRBDOS (the public domain replacement for DRI's BDOS) and discovered
>>that the HDC driver trashes the IX register SUPRBDOS is using.
>
>Boo on SUPRBDOS for doing that.
>
>CP/M-80 is an *8080* operating system.  If your BIOS or BDOS uses any of
>the z80 register set, it MUST save them or else it will break many many
>programs.  This is my biggest gripe with the turkey who did the bios and
>roms for the Osborne-1.  (grumble grumble)

     I have never had *anything* "break", although both my BDOS
( SUPRBDOS ) and my BIOS use the Z80 register set.  I would submit to you
that with the number of Z80 CP/M machines around vs. 8080 machines, any
program that assumes that the extra Z80 registers are inviolate is asking
for trouble.

     Why must the BIOS/BDOS save the registers?  You don't expect HL, or BC
to be preserved after a BDOS call, why should IX or IY be?

     BTW... has anyone noticed the following with SUPRBDOS?  Occasionally,
it will report 2 files with the same name on the same disk, although there
is only one.  It's never fatal, and never seems to show up unless SUPRBDOS
detects that you've swapped disks.
-- 

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Marc Wilson   ( mwilson@crash.CTS.COM )
     ARPA: ...!crash!mwilson@nosc
           ...!crash!pnet01!pro-sol!mwilson@nosc
     UUCP: [ akgua | hp-sdd!hplabs | sdcsvax | nosc ]!crash!mwilson
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~