From: ard_at_p850ug1.demon.co.uk (Tony Duell)
Subject: Re: PDP-8/L teletype connection
> David Gesswein
>> It took me a while to remember where they stuck the schematic for the W076
>> but I found it. If you get the 8/I maintenance manual from
>> http://highgate.comm.sfu.ca/pdp8 volume I Figure 5-7 pg 5-16 shows the
>> schematic for the W076 and the connections to the teletype.
>> I see that the page was scribbled on, the numbers from top to bottom are
>> 4 6 3 relay- 7 relay+.
>Those numbers sound like the barrier strip terminal numbers for a (real)
>ASR33 that's been converted to full-duplex. Am I anywhere close?
That is in copper on the W076 board where the cable comes off the board
to connect to the teletype. It does look like that is the teletype
connection terminal numbers.
>Be careful if you're working on an ASR33, becase IIRC the first 2
>terminals (nearest the side of the case) of that barrier strip carry live
>mains (!).
Another of those design decisions which you wonder about.
>If necessary I can look up the ASR33 connections (I have the schematics
>somewhere) and tell you what the terminals are. But remember that the
>ASR33 transmit loop is non-polarised (it's a simple mechanical switch
>network so it doesn't matter which terminal is +ve) but most electronic
>current loop interfaces are polarised and you have to get the +ve and -ve
>leads the right way round. The ASR33 manual can't help with this.
>
The ASR33 manuals are also on highgate with the schematics in print set.
Those were a bunch of loose pages in several different sizes so I may of
not had all of them.
****From: Ethan Dicks <ethan_dicks_at_yahoo.com>
Subject: Re: PDP 8/L console
- --- Lawrence LeMay <lemay_at_cs.umn.edu> wrote:
> Does anyone have that information on the W076?
>I have the schematic in the PDP-8/L reference schematics. Isn't there a
>copy of these on Highgate?
>
Highgate only has 8/I schematics, similar (I haven't found a copy of the
8/L schematics yet). I did get a copy of the module location chart
from Dave Mahoney which is on highgate.
David Gesswein
Received on Mon May 22 2000 - 06:55:23 BST