More Pick info (was Prime 2250)

From: Jay West <jlwest_at_tseinc.com>
Date: Sun Apr 11 21:39:00 1999

Prime Infomation was certainly a pick variant - I spent a lot of time (about
7 years) on Prime's and Prime Information at AB. When pick first came out,
is was what we called "vanilla" which meant that the machine booted pick -
there was no other operating system. Later other manufacturers (licensees of
pick systems) decided to strip out the monitor and missionary/native code
architecture, and gut everything that was OSlike rather than RDBMSlike. They
then put the remnants on top of some other operating system (layered rather
than vanilla). Unix was common, as was DOS, Windows, PRIMOS, etc. To answer
someone elses question, BASIC was the programming language (you had no
choice). There was also PROC which was not that much more than batch files
in DOS. Then there was the assembler. The assembler verb definition was
removed from many later versions but you could define a pointer into the ABS
area to call it up. BASIC was compiled into DCD or Pcode, and the result was
run interpretively. The DCD/Pcode was rather elegant - it implemented a
stack architecture to speed code generation and execution in RPN. At the end
of each BASIC statements resulting code the state machine was completely
back to its initial value. In a certain sense, each basic statement resulted
in a separate DCD/Pcode subroutine that was reentrant as the symbol table
and variable allocations were made out of the users workspace. All the Pick
variations handle file I/O the same - I've never seen any programming
language even close to pick basic in the elegance of the file/record
interface.

The assembler was virtual, in that the instruction set really didn't exist
on any machine. So - assembly was a 3 pass process. First, the Pick
assembler turned your assembler file into "virtual machine code". Then a
BASIC program turned the virtual machine code into an assembler program in
the native assembly language of the cpu it was running on. Finally the
native assembler was run to generate executable object code. Somewhere I
still have some listings where you can see the same program turn into 68000
assembler and then compile on a different machine and see each instruction
turn into 8080 assembler. Nifty AND educational :)

I forget if prime information was created by ex Vmark engineers, or if
Universe was created by ex Prime engineers - one way or the other ;) I have
to admit, next to freeBSD, Primos is a really nice OS IMHO.

ISTR that the baud rates for the AMLC lines (serial cards) were controlled
via the AMLC.COMI file, located on the system volume ( <SYSTEM>AMLC.COMI or
<MFD 0>AMLC.COMI). This was a command input file which set the line
characteristics. Can't recall if the console speed was set there, but the
other serial lines were. I have a complete Primos and Prime Information
manual set at the office. I'll check how to set the console speed for you.
If you have no docs and are playing with the primos machine, just remember,
it's "A " rather than "cd ", and "ED" rather than "vi" <grin> oh - emacs was
VERY common on primos, so that might be there as well for you to use.

One final note - I do NOT want to represent that I wrote the Pick operating
system, or that I was on the original development team. Dick Pick and
Chandru Murthi would just scream if I said I was. Pick was developed in the
late 60's by those two under a government project for maintaining the data
on a helicopter project. The original name (according to the US Government)
for the Pick OS was G.I.R.L.S. (Generalized Information Retrieval Language).
No Kidding. So - I didn't invent it, I was merely a freelance consultant who
worked on modifications and enhancements to the virtual code and monitor
code in the Pick OS for some of the pick licensees.

Cheers!

Jay West


-----Original Message-----
From: John Lawson <jpl15_at_netcom.com>
To: Discussion re-collecting of classic computers
<classiccmp_at_u.washington.edu>
Date: Sunday, April 11, 1999 7:43 PM
Subject: PR1ME 2550 Up and Running


>
>
> Well... it didn't hurt as much as I thought it was going to..
>
>I have just run "SHUTDN ALL" after two hours of playing with PRIMOS
>(on a DEC LA120 running at 300 baud... s-l-o-w...).
>
> I rescued this system about two months ago, and finally got tired
>of it taking up space. It took about an hour to figure out where all
>the cables used to go, and the Control Data SMD drive [used as a
>paging and swapping drive] needed a little prodding to wake it up,
>but the system boots and remembers what it was doing last time it was
>on... about six years ago.
>
> Now to try and make the console port run at a decent speed.
>
> And, apropos of the Pick discussions, this machine has INFORMATION
>loaded and running... haven't messed with it yet, tho..
>
>
> Cheers
>
>John
>
>
Received on Sun Apr 11 1999 - 21:39:00 BST