Rear-end processors for VAX

[Bill Stewart]

>  we are looking for micros to hook up to the vax for text
>  processing type jobs to take some of the loading off of the computers.
>  
>				...ihp4!tellab1!tellab2!smith
>				todd smith

We use a Bell-Labs-developed-and-built box called a "PDQ".  It's not an
externally-sold product, but it's got a commercial 68000 board living on a
Multibus with 1/2 Meg of memory, no disk, an RS-232 port, and a small
ROM monitor program that lets the host computer download software and
data files.  It normally has either nroff or troff living in it, plus
whatever file it's crunching on at the moment.  The host software
looks to see if there's a free PDQ, arranges to download n/troff if
needed and transmit the file.  If there's no free PDQ it uses "real"
troff instead.

The box costs us about $6K, and a couple of them really improve the
performance of our CPUs (we mostly use VAXen and 3B-20s, and do a lot
of troff.)  The box has about half the horsepower of a VAX 11/780,
and minimal operating system software, so you get a lot more
CPU/process on the box than on your 1/nth share of the host.
The real bottleneck is the RS-232 line (wish we could attach it to
Ethernet or a Unibus!), but our printers are attached by RS-232
anyway; you don't lose much for the typical troff-->Imagen jobs.

If you don't want to build your own box and ROM monitor, it shouldn't
be hard to take a commercial supermicro like the AT&T 3B2 or
anybody's 680x0 UNIX box, store a few standard applications on the disk,
and use uux or whatever to submit jobs to it.  (Anybody ported troff
to a Fat Mac?)

			Bill Stewart, speaking unofficially at AT&T Bell Labs

Trademarks:
	UNIX, VAX, 68000, 3B, Ethernet, Fat Mac, and Imagen are
	probably trademarks of AT&T + subsidiaries, Motorola, Xerox,
	Imagen, Digital Equipment Corporation, and Apple Computers.