Prime 50-Series emulator announcement

Dennis Boone drb at
Wed Mar 11 10:41:22 CDT 2020

I'm reposting this announcement from Jim Wilcoxson.



Date: Wed, 11 Mar 2020 08:34:13 -0700 (PDT)
Message-ID: <0c560b91-35d2-4dcc-b859-a8eb4d22bd17 at>
Subject: Prime emulator source released on GitHub
From: Jim Wilcoxson <prirun at>

Today, with much help from Dennis Boone, I'm releasing the Prime
emulator source code on GitHub for non-commercial use.  This is the full
version of the emulator running on Linux and supports:

- all Prime CPU modes: 16S, 32S, 32R, 64R, 64V, 32I
- all Prime models, from the P400 to P6550
- up to 512MB of memory, depending on the Primos rev and CPU
- a system console
- 128 incoming telnet terminal connections
- 8 disk controllers, 8 drives each
- support for all 25 disk drives sold by Prime
- a tape controller, 4 drives, using the .TAP format
- a PNC controller emulating RingNet over TCP/IP
- a bypass for Primos system serial number checks
- Unix utilities to read/write physical tapes & Magsav tapes

Dennis owns the emulator GitHub repo and has also kindly agreed to take
over hosting of the public Prime emulators that have been online since
2008.  There are 7 public emulators running in a virtual Prime ring,
allowing both remote terminal sessions (netlink) and remote disk access
via PrimeNet.  The Prime emulator on Linux is currently running 45-55
Prime MIPS in 64V mode.

A wide range of Prime software is loaded on the public emulators:

- ftn screaming fast Prime Fortran 66 compiler, written in assembler
- f77 the not-so-screaming but full-featured Fortran '77 
- pl1g the PL/I Subset G compiler
- pl1 the full PL/I compiler
- plp the original Prime systems language (like PL/I)
- spl the 2nd generation Prime systems language
- cc the C compiler written by Garth Conby of Pacer Software
- pascal the Pascal compiler
- modula Wirth's successor to Pascal
- dbg Prime's source level debugger rivaling modern debuggers
- pma the Prime assembler
- basicv the Prime BASIC compiler
- cobol the original Prime COBOL compiler
- cbl the Prime COBOL '74 compiler
- emacs the full screen editor still used by many today (me!)
- midas the Prime indexed sequential file software

This week we are working on releasing Prime disk images for all of the
public emulators to make it easy for others to get their own Prime up
and running.  For the truly adventurous who want to bootstrap their own
Prime system, there are links in the emulator readme to Prime tape
images at Bitsavers and to a large library of Prime manuals.

I learned more about operating systems, compilers, concurrency, and
other systems programming topics by reading Prime source code, making
changes to Primos, and fiddling with Prime hardware, than I did from all
of my college degree work.  I loved Prime computers, Prime software,
Prime hardware, and the Prime Computer company, and am grateful to all
of the former Prime engineers that provided this robust and interesting
hardware and software platform.

I hope you enjoy it too!


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