[COFF] IBM 1403 line printer on DEC computers?

[COFF] IBM 1403 line printer on DEC computers?

[Paul Winalski]

There's been a discussion recently on TUHS about the famous IBM 1403
line printer.  It's strayed pretty far off-topic for TUHS so I'm
continuing the topic here in COFF.

DEC marketed its PDP-10 computer systems as their solution for
traditional raised-floor commercial data centers, competing directly
with IBM System 360/370.  DEC OEMed a lot of data center peripherals
such as card readers/punches, line printers, 9-track magtape drives,
and disk drives for their computers, but their main focus was low cost
vs. heavy duty.  Not really suitable for the data center world.

So DEC OEMed several high-end data center peripherals for use on big,
commercial PDP-10 computer systems.  For example, the gold standard
for 9-track tape drives in the IBM world was tape drives from Storage
Technology Corporation (STC).  DEC designed an IBM selector
channel-to-MASSBUS adapter that allowed one to attach STC tape drives
to a PDP-10.  AFAIK this was never offered on the PDP-11 VAX, or any
other of DEC's computer lines.  They had similar arrangements for
lookalikes for IBM high-performance disk drives.

Someone on TUHS recalled seeing an IBM 1403 or similar line printer on
a PDP-10 system.  The IBM 1403 was certainly the gold standard for
line printers in the IBM world and was arguably the best impact line
printer ever made.  It was still highly sought after in the 1970s,
long after the demise of the 1950s-era IBM 1400 computer system it was
designed to be a part of.  Anyone considering a PDP-10 data center
solution would ask about line printers and, if they were from the IBM
world, would prefer a 1403.

The 1403 attached to S/360/370 via a byte multiplexer channel, so one
would need an adapter that looked like a byte multiplexer channel on
one end and could attach to one of DEC's controllers at the other end
(something UNIBUS-based, most likely).

We know DEC did this sort of thing for disks and tapes.  The question
is, did they have a way to attach the 1403 to any of their computer
systems?

-Paul W.

[COFF] Fwd: Fwd: IBM 1403 line printer on DEC computers?

[Clem Cole]

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FYI: Tim was Mr. 36-bit kernel and I/O system until he moved to the Vax and
later Alpha (and Intel).
The CMU device he refers is was the XGP and was a Xerox long-distance fax
(LDX).  Stanford and MIT would get them too, shortly thereafter.

---------- Forwarded message ---------
From: Timothe Litt
Date: Thu, Dec 21, 2023 at 1:52 PM
Subject: Re: Fwd: [COFF] IBM 1403 line printer on DEC computers?
To: Clem Cole

I don't recall ever seeing a 1403 on a DECsystem-10 or DECSYSTEM-20.  I
suppose someone could have connected one to a systems concepts channel...
or the DX20 Massbus -> IBM MUX/SEL channel used for the STC (TU70/1/2)
tape and disk (RP20=STC 8650) disk drives.  (A KMC11-based device.)  Not
sure why anyone would.

Most of the DEC printers on the -10/20 were Dataproducts buy-outs, and were
quite competent.  1,000 - 1,250 LPM.  Earlier, we also bought from MDS and
Analex; good performance (1,000LPM), but needed more TLC from FS.  The
majority were drum printers; the LP25 was a band printer, and lighter duty
(~300LPM).

Traditionally, we had long-line interfaces to allow all the dust and mess
to be located outside the machine room.  Despite filters, dust doesn't go
well with removable disk packs.  ANF-10 (and eventually DECnet) remote
stations provided distributed printing.

CMU had a custom interface to some XeroX printer - that begat Scribe.

The LN01 brought laser printing - light duty, but was nice for those
endless status reports and presentations.  I think the guts were Canon -
but in any case a Japanese buyout.  Postscript.  Networked.

For high volume printing internally, we used XeroX laser printers when they
became available.  Not what you'd think of today - these are huge,
high-volume devices.  Bigger than the commercial copiers you'd see in print
shops.  I(Perhaps interestingly, internally they used PDP-11s running
11M.)  Networked, not direct attach.  They also were popular in IBM shops.
We eventually released the software to drive them (DQS) as part of GALAXY.

The TU7x were solid drives - enough so that the SDC used them for making
distribution tapes.  The copy software managed to keep 8 drives spinning at
125/200 ips - which was non-trivial on TOPS-20.

The DX20/TX0{2,3}/TU7x *was *eventually made available for VAX - IIRC as
part of the "Migration" strategy to keep customers when the -10/20 were
killed.  I think CSS did the work on that for the LCG PL.  Tapes only - I
don't think anyone wanted the disks by them - we had cheaper dual-porting
via the HSC/CI, and larger disks.

The biggest issue for printers on VAX was the omission of VFU support.
Kinda hard to print paychecks and custom forms without it - especially if
you're porting COBOL from the other 3-letter company.  Technically, the
(Unibuas) LP20 could have been used, but wasn't.  CSS eventually solved
that with some prodding from Aquarius - I pushed that among other high-end
I/O requirements.

On 21-Dec-23 12:29, Clem Cole wrote:

 Tim - care to take a stab at this?

ᐧ

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