27 Mar
2002
27 Mar
'02
11:15 a.m.
At 03:06 PM 3/27/2002 -0800, Stan Sieler wrote:
Did users commonly compile on system A and then take
the P-Code to
system B and run it successfully?
I'd have thought that media incompatibility would have tended to
limit this capability.
Was any commerical P-System software sold that was a single binary,
but the vendor expected the user to be able to install/run it on
any brand/model of P-System? (Or, did vendors have to produce a version
for every platform?)
Although I wasn't intimately involved with the P-System
commercial software market in the early 80s, I do have a
page on it on my web: http://www.threedee.com/jcm/
With each revision of the operating system (II, IV, etc.)
they changed the opcodes, which caused incompatibility.
The Pascal language implementation changed with each
major version, too.
Also, each platform tended to have its own library of
platform-specific routines. Any programmer had enough tools
at their disposal to create their own library of custom
function calls, which could jump into native assembler.
Those calls were commonplace on any app that did interesting
things by becoming intimate with the hardware - sound, video,
block access to disks, serial ports, etc. No doubt these were
some of the most popular apps on any platform, being able to
connect to modems, do fast non-text graphics, or beep the
speaker, etc.
I believe if an app stuck to straight UCSD Pascal and text I/O,
you can move it across media and platform (to a system of the
same version) and it would run. Certainly media conversions were
more daunting in those days, too.
On the other hand, the UCSD P-system for the original IBM PC
still runs in a command window in Windows 2000. Out of the
box compatibility after almost 20 years!
- John