[vcf-midatlantic] UCSD P-System on a hard drive - any pointers?

Glenn Roberts glenn.f.roberts at gmail.com
Sun Apr 1 11:39:24 EDT 2018

Can't recall if I've asked this here before - looking for anyone with
personal experience or connections to enable hosting the UCSD P-System OS on
an 8-bit system (Heathkit) with a hard drive.  I'm looking for more depth
than you can find by just Googling (I'm familiar with most of that content I
think).  I'm not that interested in the later version by Pecan that was for
the IBM PC.


If you've no interest then thanks and enjoy your day, otherwise more detail
below.  tx!


*	Glenn



I have fond memories of using the P system on a Terak 8510a - that was a
pretty cool platform (LSI-11 based; wondering - does the museum have one?)


P-System was never a big success for multiple reasons, but it has some nice
qualities that make it worth preserving, including full screen editing and
an IDE-like environment, semi open source (at least the pre-commercial
versions done at UCSD) and broad platform support.  It was a learning
environment that I suspect influenced many who were new to computer science
in the late 70's so it deserves a place in the annals of personal computing


I'm working on a Heathkit platform (H8 or 89).  I have the Heath
implementations (both rev II and rev IV) but Heath never bothered to support
their own hard drive (Z67) - probably because the P-System was rapidly
fading around the time that came out.  Working with floppy versions is
tedious and unreliable - I'd like to host this on my Z67 emulator on the


I'm aware that UCSD has released the earlier versions (I.5, II) but the most
promising approach (I think) is to use the later "CP/M Adaptable" release.
This uses a translator layer to map the P-System BIOS to the CP/M BIOS.  We
already have CP/M BIOS support for the Z67.  The preferable release would
seem to be Rev IV from Softech since that supports "Winchester" drives and
memory swapping, etc.  Again I have a licensed copy of the IV release but
it's the Heath tailored one - I'm thinking the CP/M Adaptable one is a
better starting point.  I've found many of the needed pieces of this in the
Maslin archive and in Bitsavers so I've got most (maybe even all) of the
pieces of the puzzle but it's a bit tedious to piece together a working


So if you've got experience (or only interest) in this topic or more
importantly know of any substantial work that's been done (or an "expert" -
perhaps someone from Softech or the original UCSD team?) I'd be interested
in more information.  Thanks! - gfr 




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