Subject: Yippee! more PDP-8e owners

From: [email-masked] ("Stephen Walters")
Date: Sun, 8 May 1994 14:48:29 GMT

I Consider myself quit lucky....I have a PDP 8/e with 12k words of CORE, 
ASR Teletype....a large collection of paper tapes and....the original 
sales brochure from 1972...used to sell it!!

Neat...What I would like to do is get the teletype, with it's paper tape 
reader to work...I have focal-8, os-8 and assorted assemblers....Ideally 
I'd like to upload the tapes to a PC (as a teletype replacement) and do 
away with the teletype all together.

Any suggestions?

[email-masked]

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From: [email-masked] (Jim Corder)
Date: 11 May 1994 09:11:00 -0400

In article <[email-masked]>,
Stephen Walters <[email-masked]> wrote:
>I Consider myself quit lucky....I have a PDP 8/e

Hello:

	OK, I have been reading this group for a few months now.  I have
yet to figure out what I want to do with my PDP 8/e.  I have had an 8/e
in my basement for about 4 years now.  I read the manuals, "to start call
your dec rep..."

	My 8/e is in a 6' tall cabinet.  I have two "rko5"? drives, and
a dec write ][.  Each drive has a single platter disk in it.  I have several
other platters in boxes.  The CPU is on the top with the two drives under it.

	I wanted the cabinet and also got a free 8/e full of cards and stuff.

	I have never tried to start it, or even plugged it in.  I have had
a few offers, but have never parted with it:  It looks neat:-)  There isn't
a paper tape just a lot of toggles.

	Does anyone know how to start this thing so it uses its drives?
How do you hook the "mini-loop" dec writer ][ up?...

Thank you,
James D. Corder
[email-masked]

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From: [email-masked] (PDP11 Hacker .....)
Date: Wed, 11 May 1994 17:26:00 GMT

In article <[email-masked]>, [email-masked] (Jim Corder) writes...
>In article <[email-masked]>,

Greetings from a fellow PDP8/e owner :-)

>in my basement for about 4 years now.  I read the manuals, "to start call

What manuals do you have? The manuals that came with my 8/e (The 3-volume
maintenance manual) say nothing like that. Instead they land you in the middle
of the CPU on about page 5. Mind you, I much prefer manuals like that - I don;t
mind having to think a bit, but content-free manuals make me want to give up.

Anyway, My recomendation is to get the CPU working first, and then to sort out
the drives and terminal systems.

>	My 8/e is in a 6' tall cabinet.  I have two "rko5"? drives, and

That's RK05 (Numeric 0). They're about 2.5Mbytes/pack (I'm not sure about the
exact capacity - PDP11's fit 12 sectors (16 bit words) on a track, PDP8's fit
16 sectors (12 bit words) in. Each sector is 256 words (?) and there are about
200 tracks on the disk, and 2 heads.

>other platters in boxes.  The CPU is on the top with the two drives under it.

Make sure you're using 16 sector packs (17 notches in the hub flange), not the
more common 12 sector type.

>	I wanted the cabinet and also got a free 8/e full of cards and stuff.

I had the revers problem. I wanted the PDP8/e CPU, and had to take the rack and
drives with it. Still not collected the drives...

>a paper tape just a lot of toggles.

You don't need paper tape. You can use the toggle switches to load a bootstrap
(if you don't have a boot rom), and run quite happily from the drives.

>How do you hook the "mini-loop" dec writer ][ up?...

OK. I really suggest you get the CPU working before you go any further. My
sequence would be : 

1) Open the CPU box, note down the numbers (Mxxxx, Gxxxx, etc) on the handles
of the cards, and post it here. Then I'm sure we can tell you exactly what you
have (if you have a boot ROM for instance).

2) Unplug the 2 40-way ribbon cables going to the drives. Also unplug the
drives from the power distribution box.

3) Turn on the mains to the CPU. If you are careful, like me, you'll unplug the
power connectors from the CPU psu (2 white 6-pin plugs) and check the +5V line
at the PSU with a voltmeter. Saves wiping out the entire set of chips if
something is wrong.

4) Try loading an address (set the address on the switches) and press Load
Address. Check the top row of lights shows the address you entered.

5) Try depositing some data (Enter a suitable (low) starting address. 0 will do
nicely. Set the switches to a patern, raise and release deposit. Check the
address increments each time. Repeat this a few times.

6) Read back what you just deposited. Load the start address again, an then
repeat. You have to put the rotary switch in the right postion - but I forget
which. Try MD data for a start.

7) Load a little test program. There's a nice 4-instruction one, which I
forget, but I'm sure someone else will remind me, that repeated increments the
accumulator. Get that running, and you can watch the accumulator incrementing
on the front panel lights.

Now, the Decwriter 2 plugs into a serial interface card. You'll probably have
at least one M8650 or M8655 in the machine. You'll find a cable connected to it
that the DECwriter will plug into (I hope - if not, You'll need the pinouts of
both, which means I'll have to start digging). If you have several serial
cards, you'll need to find out which is the console (by the settings of the
address switches or links), and link the terminal to it.

>James D. Corder

-tony

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