12 Mar
2009
12 Mar
'09
1:06 a.m.
On Thu, Mar 12, 2009 at 12:32 AM, James Fogg <james at jdfogg.com> wrote:
It had 4 RL02's, but I'm donating 2 of them to a friend.
Ah. A good friend you are indeed.
That's one peripheral I've never owned or seen running. I have some
DF32 disks - sorta like the RF08 (right down to a nearly-identical IOT
instruction set), but 32K words per drive unit, max 4 drives (1 DF32,
3 DS32 expanders). The RF08 is much larger, IIRC.
Q-bus PDP-11/23 in the Dec half-height cabinet with 2
RL02's (a common
configuration apparently).
Yes... a common 1980s small office configuration... (we
were using a machine with only 4 RL02s for a RSTS-based accounting
system for a multi-million-dollar company in 1984). And it was used
for accounting. Did this company live somewhere near Belcher's Falls, MA?
Nope. Columbus, OH; and I know nobody else could have parts from it,
because I got to keep it when the company folded (it was repurposed in
the early 1990s anyway, into a RSTS v9 development platform for the
company's products on behalf of the very few customers who were still
on RSTS that late).
Yes, checking google shows me its in a BA23. This
system was pieced
together and the case isn't exactly complete.
Ah. Well... depending on what used to be in that BA23, who knows what
the badge originally might have been. We got a MicroVAX II badge when
we upgraded a uVAX-I to -II back when they were all new (and an
expensive upgrade it was!)
Oooh... nice.
?What disk? ?RF08? ?RK05F?
RF08. It also had lots of core, either 16k or 32k in four
boards if that
sounds right. It was the maximum it could support.
32K is the max memory without a KT8A memory management board, but as
for 4 boards, it depends on the boards. I've seen 4K stacks, I've
seen 16K stacks. I might have even seen 8K stacks, but if someone
swears they don't exist, I'm probably wrong.
8K is an important threshold because that's the minimum to run OS/8.
12K is important for users of certain system devices (like DECtape)
because there needs to be memory to hold the second page of a two-page
system handler. 16K is a nice round number, and 32K is a "full boat".
ADVENT needs 32K. Most other programs I've personally run across
will run in 16K.
It had a paper tape reader too. At the
time I had no understanding of its significance. I read enough manuals to
get it to boot and I remember running a program or two but that was it. It
was clean and running, with a box full of tapes and a few boxes of
manuals.
I have -8s with papertape only, and a few newer units with 8" floppy,
5.25" floppy and a couple flavors of hard disk. Any machine with
enough memory (and storage) to run OS/8 is interesting by itself, but
even 8K-12K and papertape BASIC is accessible to most folks with 1980s
computer experience. (FOCAL runs in 4K, but that's an entirely odd
environment for BASIC wonks, IMO).
At the time my surplus Xerox 820 with W0RLI packet BBS
software
and dual 8 inch floppy disks had much more of my attention and it could
fit in my apartment.
Ah... well a Xerox 820 is quite probably rarer than _a_ PDP-8, but the
RF08 made your -8 somewhat uncommon.
-ethan