-----Original Message-----
From: Ethan Dicks <ethan_dicks(a)yahoo.com>
To: Discussion re-collecting of classic computers
<classiccmp(a)u.washington.edu>
Date: Thursday, November 04, 1999 2:42 PM
Subject: Fwd: Finally got a "straight" DF32 yesterday
--- John B <dylanb(a)sympatico.ca> wrote:
Looks like the PDP 8/S will be running a lot more
than FOCAL in the near
future.
Cool.
Yesterday in our snow storm I picked up:
DF32 with docs and "Disk Monitor" paper tapes. This is the first series
DF32s with the "R" series modules and no "8I switch".
What's the -8/I switch? I have several DF-32's. All well used and not
necessarily working (I have played with them but never really tried to use
them for storage - the rotation sensor has been verified on at least one
drive, but that's about it). One set came with the straight -8s, another
set came with the -8/I.
Depending on the DF32, I have found two transistor versions. One with a
rotary switch on the right side of the front and one without. The switch
allowed you to select "PDP 8, 8/S, 8/I". I went through the logic today and
all looks good. (I am NOT spinning the drive up.....yet).
If you get this working, I'd love to get a copy of the tapes - I have
an -8/I
that may someday have 8K on it (if I sacrifice an -8/L
by stealing its
core;
I have N machines that use them and (including the
second field on
the -8/I),
N-2 core stacks) I'm thinking of wiring up some
CMOS static RAM on the
pins
of an -8/L for its 4K and migrating the core to the
-8/I). I could use the
slot between the planes on the core stack for workspace It's unpopulated.
You don't need 8K for DM. It happily works in 4K of space (with FOCAL 1968
[I have two versions of focal - any idea why????]). I am just getting
together a list of tapes and boards now to help folks out. I played the dice
game today (craps - 5/8-14 ). Pretty cool!
> This unit was wrapped in plastic
> and was used as a spare - it looks like it was used very little. I also
got
a new spare
disk for it if I need it.
You know that the heads crash everytime you power it off, yes? They are
the
kind of disks you power up and leave on forever. In
the real world, when
the
osmium coating wore too thin to record data, DEC FS
flipped the disk once
and reformatted.
Yes I do. People have been warning me.... and I have *one* thing to say. I
didn't get this far with this transistor computer to let some silly design
flaw stop this system from running a disc. I will modify the hardware anyway
I can to stop it from crashing (even add some solenoids to pull the heads
back if I have to!). I want to keep this system "chip" free... I almost fell
over when I saw the "disc file" had no chips too!
I will have this system done when it is running only/all transistor
peripherals it now has plus the DF32 with DM software and the 32B
Oscilloscope interface.
But... the
DF32 needs 13 I/O cables to
connect to the 8/s. Anyone still selling these kinds of things?
I do not know *who* would have that sort of thing. I have one set per
master
drive. No spares. Sorry.
> H901 Flip Chip Patch Panels - These are really sweet. You basically plug
the
flip chips in
the back and use banana plugs in the front. Also, (I didn't
know this at the time) hundreds of those "plastic" cards for the front of
the H901 to make it easy to wire circuits.
Is this the original DEC logic experimenter's board? There were two
produced:
one for DTL, one for TTL. I got a classroom book for
the TTL version when
I
was in grade school. I did many of the exercises on
paper since I didn't
have
the hardware to try stuff out on.
Yes they are. You can find them in the DEC handbooks. These only support
A,B,R,K,W flip chips... sorry no Ms :-) . Only for the transistor stuff!
> I am building a quick testing station with the H901s with the 8/s so I
can
quickly fix
these Flip Chips so I can provide a list on my website for
anyone who needs one.
I'd love to see pictures.
I am putting pictures online this weekend and will update everyone here. I
installed the H901 panels on the 8/s so I can start some "testing" fun. I
have to go out this weekend to buy some banana plug test leads for
interconnection. These make it a lot easier to work with flip chips.
I think I am going to have our graphic designer make a "No Chips Allowed"
gif for the page.
> I will update the webpage over the next few weeks
to catalog the parts
and
software I
have to help others with their old transistor computers.
Perhaps in a couple of months, I'll dig down through the pile far enough to
begin to recondition the cleaner of my Straight-8s. The dirty one was
apparently from a newspaper and coated in ink. It has a PA-60 which is, I
think, some kind of typesetter's interface.
Good stuff. I really enjoy restoring transistor systems.... it's made PDP
11s/newer 8s really boring. I am sure you will have as much fun as I have.
> Updates to members here (trying to save
bandwidth)
>
> Chuck: I am going to storage this weekend. I will look for the RK8E
cables
> for you. I don't need them as I don't like
any "IC" PDP-8.. well, maybe
an
8I.
You have maybe an extra RK8E that you aren't going to use? All I have for
hard disk on ONMIBUS is RL01/RL8A sets. I've never had any RK stuff for
the -8. I do have this 16-sector RK05F pack (and no 16-sector RK05J packs,
only 12 sectors) that I'd love to read, but we've been over this on the
list before. At this point, I'd probably have to hack one of my RK05J
drives
and replace the heads, realign it to match the pack,
back it up, etc., etc.
I've always wondered what's on it. I've had it since 1984 and never owned
the
gear to read it.
I have 8 RK05 drives. They all run well. I use to add as many of them as I
could. I am looking for newer PDP-8 parts for folks here as I use to scrap
them up to a couple of months ago. I even found bits of an 8I I butchered 15
years ago... I could never understand how someone could get excited about a
12 bit computer in 1972 when all the big boys were 16 bit or more. If I
still have the cables he can have them. Besides, even if I tried to patch an
RK05 to the 8/s (with about 400 flip chips) I would be doing it's "chip
free" atmosphere a real disservice.
john
-ethan
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