Date   : Fri, 15 Mar 1991 21:20:35 GMT
From   : pilchuck!dataio!fnx!del@uunet.uu.net (Dag Erik Lindberg)
Subject: Re: About CP/M-80 emulator on PC AT

In article <9103110804.AA04098@ucbvax.Berkeley.EDU> MONTARON@FRP8V11.BITNET
(Alexandre Montaron) writes:
>Hello|
>
>   I've juste bought MEDIA-MASTER v5.01 which now include a CP/M-Z80
>software emulator... for PC XT or AT...

I have Media Master.  It's a *great* product for copying various formats
of CPM disks to MessyDos, but it's emulation of CPM was pretty poor.  I
couldn't get Zork to give a nice looking display :-)

I found Z80MU to be a much better product for emulation.

>   It emulator either Z80, 8080 (software), and for which who have a
>NEC V20 instead of a intel processor: 8080 (hardware)... because this chip

The latest version (the commercial version) of Z80MU also supports this,
although Joan recommends against it due to some (unspecified) bugs in the
8080 emulation of the V20.

>   This emulator permit to acces I/O port... To acces RS232C for example (|)

The commercial version of Z80MU also allows access to I/O ports.

>And they have add a new Bdos fonction which permit to call any PC's bios fnct
>   But it simply emulator a CPM22 (or perhaps a ZCPR because of the LIST cmd?)
>           But it exist... Try it |       Bye| Alex.   <MONTARON@FRP8V11>


I have not gotten the auto-install version of ZCPR to work with Z80MU,
because there is no real BDOS, just a funny little 256 byte trap
area.  I suspect that Media Master would suffer from the same deficiency(?).

Regarding Z80MU:

It is an impressive product.  I tried the commercial version and did not
like it, for a very application specific reason.  I actually run Unix,
with an MSDOS emulator, running the CPM emulator.  The new commercial
version of Z80MU has gobs of screen output with formatting and cursor
addressing junk.  Probably looks great on a regular PC, but in this
particular configuration screen I/O is expensive.  My application is
a database written many years ago when I was running CPM exclusively and
is too expensive to port.  I find disk operations are considerably faster
than the old 4Mhz Z80 floppy only system.  CPU intensive stuff is
noticeably, but not objectionably, slower than the Z80.  (This is on
a 20Mhz 386, under VP/IX).  Screen I/O on the Z80MU freeware version is
slow, but not painfull.   Under the commercial version it is just
unacceptable (Note that this is probably not the case running under
standard MSDOS where direct screen I/O is really direct).

BUT:

I picked up a PC BLUE Z80 coprocessor for a good price, and when installed
in an otherwise worthless XT I found an excellent CPM machine.  Running
at a full 4Mhz, combined with the XT's fast disk I/O and 40MB of hard disk,
it makes an excellent solution.  This is not really CPM, in that you work
at the dos prompt, and all normal DOS tools are available (such as a
real 'make' which I never had under CPM, and real date stamping, etc),
while the CPM programs automatically run under the coprocessor and exit
back to dos when done.  The real disadvantage is that I have to work on the
XT machine instead of the much preferrable Unix machine.  Now if I could
just get a coprocessor that would run under Unix, I might have the 
perfect setup :-)


-- 
del AKA Erik Lindberg                             uunet!pilchuck!fnx!del
                          Who is John Galt?