TOM WALKER wrote in a message to ROY J. TELLASON:

RJT> TW> That is how it started I think .Like CP/M since then there are soem
RJT> TW> non compatable implementations. BUT it is Still an Operating System
RJT> TW> tha same as the mostly NON compatable versions of CP/M.

RJT>What are you talking about with non-compatible versions of CP/M? 
RJT>The major differences were in the different manufacturers using 
RJT>different disk format but the OS itself,  and most of the 
RJT>software,  worked across all machines pretty much.  There were 
RJT>programs (Uniform, Media Master) that worked to ge across disk 
RJT>formats,  too.

TW>  Well in my Experience the program compatability was poor
TW> Particularly  with thc Major manfacturers. They DID slightly tweek
TW> their CP/M OS and  delibertly wrote the programs to need those
TW> tweeks to LOCK YOU IN!! 

TW> Thewre were of course some exceptions, THAT is why I used the word
TW> "SOME" i nmy post.
TW> The most notable one was KayPro and Commodore making their CP/M
TW> machines compatable with the Osborne CP/M that had a somewhat large
TW> base of programs to draw from.

Commodore was a world unto itself,  and a poor cp/m machine at best.  I
tried some programs that I was familiar with on a c128 running cp/m,  and
they ran pretty slow.  Those machines also had a whole lot of proprietary
aspects that were often shoved into the cp/m side of things,  which didn't
particularly enhance the use of it.  Kaypro and Osborne were pretty much
compatible with each other,  the major differences being the disk formats
and the screen control codes,  but that was the case with *any* cp/m
software.  Pretty much of what was out there,  unless it was *extremely*
vanilla stuff,  had to be patched to use the right screen control codes
(escape sequences usually) for the machine or terminal it was to be used
with.

I know of no manufacturer that tried to lock anybody in to anything,  nor
software publisher -- why would they try and limit their marketplace like
that?

---