Date   : Tue, 13 Oct 1992 16:01:39 GMT
From   : destroyer!sol.ctr.columbia.edu!hamblin.math.byu.edu!hellgate.utah.edu!cc.usu.edu!ivie@gumby.wisc.edu (CP/M lives!)
Subject: Re: Will CP/M software work on any CP/M ???

In article <9210131319.AA13429@deepthought.cs.utexas.edu>, STDN%MARIST@VM.MARIST.EDU
(Dan Newcombe) writes:
> Hi,
>  I have been trying to find some CP/M database software for
> a friend who has a DEC Rainbow 100 computer.  I know that
> there is a HUGE supply of CP/M stuff at Wuarchive.  Would
> I be able to download this stuff, transfer it to a disk
> via a CP/M read/write program and get it to work on the
> DEC with no problems???  As I remember, CP/M was based on the
> 8080 chip and instructions, so it shouldn't be a problem, right?

In most cases, you can run CP/M software on any old CP/M machine. There are
exceptions; software that utilizes the particular I/O ports of a certain
machine, for instance. You will probably have to customize some software to 
talk to the terminal (in this case a VT100). This is always interesting.

The DEC Rainbow is an odd CP/M box. It is primarily a CP/M-86 box with a 
Z80 off to the side running the floppies. The 8086 can ship a CP/M-80
program over to the Z80 and run it. Since the 8086 is running the BDOS, the 
Z80 has lots of extra memory space that it wouldn't normally have. I did have
trouble getting the I/O byte to work properly from the Z80, and this is the
primary reason that I decided to use other machines.

The oddest CP/M box that I know of is the DECmate II, which I am using right
now. The DECmate II is primarily a PDP-8 based word processor with a Z80
coprocessor card. The Z80 does not have direct access to the hardware (the 
BIOS runs on the PDP-8), but since the I/O byte is correctly implemented
that isn't really a problem; I run, for example, the exact same version of
KERMIT on the DECmate II that I use on the Televideo 802.

The most interesting problem that I've had getting CP/M software to run on
the DECmate involved some software that did not know how to put out ASCII
coordinates for the VT100 emulation. I had to patch the startup banner of
that program to include the Switch-to-VT52-mode escape sequence, and then
patch the program to run a VT52.

Roger Ivie
ivie@cc.usu.edu