🚀 go-pugleaf

PRO 350 is a PDP11 which runs P/OS, an RSX11M+ derivative. It has slots,
but they're a DEC format. Serial printer support is included (trivial really
to do on a multitasking OS).
  While P/OS isn't quite RSX11M+ (unfortunately), nearly ALL the RSX tools
developed over the years run on it. You generally need the native toolkit
to do anything serious with the machine; make SURE you get that with
any pro. (P/OS without it is good for running canned applications from
menus and not much else.) There are a good fraction of a gigabyte of
such tools in public domain. Some are available via the DECUS library.
More can be found on the RSX SIG tapes (from 1977 to 1988 so far, and
yes, there WILL be an important one for spring '89 including an update
to DECUS C). Things like free C, Pascal, Basic, Focal, Lisp, Forth,
and many more are available in languages. Numerous editors and some
PD word processors (e.g. Brian Nelson's TED) are there too.
  With p/os V2 and the toolkit one must say "spawn .pip [*,*]*.*/pu"
for example. Since there would normally be task name conflicts with
a subsequent DIR (which uses the pip program) one then uses the other
little RSX SIGtape gem TRN to rename all tasks. Just say TRN and everything
at your "terminal" gets a new and unique name and off you go...no more
name conflicts. Makes it easy to do stuff in background; as many
things as you like generally.
  The PRO does not have windows at this level, though there is software
to run applications in windows. They have to be designed for the windows
though. The normal console acts like a terminal. Therefore you need to have
SOME concern about what you're talking to. In practice, this is not a
great limitation, since basically everything accepts commands from command
lines and useful work can be accomplished via shooting one liner commands
at different tasks.
  Things like PD memory disks for PRO exist also. For heavily overlain
programs (like AnalytiCalc, my spreadsheet, which has 5 cotrees and
a zillion leaves in the overlay structure) it is a MAJOR win to run
the overlain program off a memory disk; factors of 10 in speed are
possible. For most PRO programs this is not a factor. You can get
rid of the thing if needed.
  A pro reads/writes ODS-1 RX50's. VMS comes with F11AACP (not always
installed on microvaxen but present on distribution kits for vms)
which can read/write these. Also micro-RSX can read/write them.
I don't have immediately any ods-1 reader for MSDOS, though there
is a PD RX50 driver for the 1.2 meg drive on IBM AT that can
read/write RX50 in MSDOS format. I suspect one of the PD ods-1
readers for RT11 or Unix might be a way to go in forging such a link.
Anyone have such a thing now? (Might be a good thing for the spring
'89 RSX tape.)
  I hope this is helpful. By the way, I cannot overstate the value of
multitasking. On a PRO you almost NEVER have to wait for the computer
to be free if you get in the habit of using the multitasking. On a
PC, I've sat waiting for long processes to finish every time I've
used one (often). My home machine these days is an Amiga, which also
multitasks. I NEVER have to give up the machine access due to long
operations there! If you're computing experience has been that you
have to wait for the last operation to complete before doing the
next, let me urge STRONGLY that you move up to something that will
multitask. The pro is a VERY inexpensive way to see this since the
price cuts, and due to the availability, essentially free, of C and
Pascal (plus non-free but cheap languages from dec) there's quite
a lot you can do on the machine that will remain useful on other
engines also.
  By the way, there's a working group in the RSX SIG which is devoted
to helping folks with non-magtape media get hold of software off the
sig tapes; Bob Uleski heads it. 
Glenn Everhart
Everhart%Arisia.decnet@ge-crd.arpa