28 Jun
2007
28 Jun
'07
1:18 p.m.
Hi,
I have a couple of the old GPO [1] Modem 2B units....
Brings back memories....the 2B was my first modem back in '85.
Lots of fun, but not as convenient as one which responds to Hayes "AT"
commands.
I may still have some documentation somewhere if it's any use to you?
TTFN - Pete.
29 Jun
29 Jun
3:17 p.m.
Hi,
Did you get it from 'Display Electronics'? They were advertising them at
the time. I bought mine at a radio rally, and were alsmost certainly the
end of the Display Electronics stock (I got some other things at the same
rally that had been advertised previously by the said company).
Incidentally, of my 2Bs as a 'GPO' badge on the front, the other has
'British Telecome'.
Somewhere I have a D1200A modem (I forget the GPO designation). That's
the same caxe, but with innards for a 1200 (transmit) 75 (receive)
system. In other words the host end of Prestel.
I have a couple of the old GPO [1] Modem 2B
units....
Brings back memories....the 2B was my first modem back in '85. Lots of fun, but not as convenient as one which
responds to Hayes "AT"
commands.
Depedns on what you want to use it for :-)
I may still have some documentation somewhere if it's any use to you?
I'd be interested in knowing what you've got, certainly...
-tony
5:10 p.m.
On 29/06/07, Tony Duell <ard at p850ug1.demon.co.uk> wrote:
Did you get it from 'Display Electronics'? They were advertising them at
the time. I bought mine at a radio rally, and were alsmost certainly the
end of the Display Electronics stock (I got some other things at the same
rally that had been advertised previously by the said company).
Incidentally, of my 2Bs as a 'GPO' badge on the front, the other has
'British Telecome'.
I had a 2B - bought from Display! GPO badge... I ran a BBS on it for
several years (the BBC micro sat on top of it!) until I got a
prototype nightingale auto-answer from Pace.
I remember being fascinated by the kit they had available, but it was
tricky enough getting the 2B home to Manchester.. I seem to recall I
persuading my mother to take me there on one of our periodic
"holidays" in London; I don't think either of us anticipated the size
of the thing!!
Rob
I have a couple of the old GPO [1] Modem 2B
units....
Brings back memories....the 2B was my first modem back in '85.
11:12 a.m.
I had a 2B - bought from Display! GPO badge... I ran
a BBS on it for
several years (the BBC micro sat on top of it!) until I got a
prototype nightingale auto-answer from Pace.
Incidentally, the 2B has a ring-detect relay inside, which asserts Ring
Indicate (pin 22) of the RS232 connector when trigger. You have to make a
few more conenctions to tbe barrier strip, in particular one to the bell
wire in the telephone cabe, and add a 3K resistor (or a Thermistor 13A?).
I built a box off TTL that sits on top of the 2B and which does
auto-answer (inculuding hanging up after a suitable time delay if it
looses carrier), dialing (by toggling the DTR line the right number of
times, etc. I probablty still have the scheamtics somewhere, along with
the notes I made on linking up the ring detect relay.
I remember being fascinated by the kit they had available, but it was
A lot of it seemed to be very expensive and not in particularly good
condition.
tricky enough getting the 2B home to Manchester.. I
seem to recall I
It couldn't be worse than the time I took a GT40 (complete with monitor)
on a train from Bristol to London :-)
-tony
1 Jul
1 Jul
8:17 a.m.
On Sun, 1 Jul 2007 00:12:50 +2500 (BST), Tony Duell
<ard at p850ug1.demon.co.uk> wrote:
indeed ... I didn't buy anything else from there.. I think they had
reuters board beeb's though, which almost tempted me..
I beat it several years later by carrying a BBC B, dual floppy drives,
box of software, and a very heavy amcom 10MB hard drive unit in it's
shipping box on the train back down to London.. I'm fairly sure I
never tried carrying a monitor tht far though!!
Rob
Incidentally, the 2B has a ring-detect relay inside, which asserts Ring
Indicate (pin 22) of the RS232 connector when trigger. You have to make a
few more conenctions to tbe barrier strip, in particular one to the bell
wire in the telephone cabe, and add a 3K resistor (or a Thermistor 13A?).
Yes, I think i did that.. the beeb looped waiting for ring detect, and
lifted dtr to answer the line. I then had a background routine that
polled carrier detect and interrupted the bbs software on line drop.
I built a box off TTL that sits on top of the 2B and which does
auto-answer (inculuding hanging up after a suitable time delay if it
looses carrier), dialing (by toggling the DTR line the right number of
times, etc. I probablty still have the scheamtics somewhere, along with
the notes I made on linking up the ring detect relay.
Ingenious,, probably a bit beyond me at the time though..
I remember
being fascinated by the kit they had available, but it was
A lot of it seemed to be very expensive and not in particularly good
condition. tricky enough getting the 2B home to Manchester..
I seem to recall I
It couldn't be worse than the time I took a GT40 (complete with monitor)
on a train from Bristol to London :-) 
9:48 a.m.
New subject: PDP-8/E Top Cover
Were any of the Digital PDPs standardized as far as the top covers? I am
looking for a PDP-8/E top cover and wondering if any other model had a
similar top. Thanks.
Todd Paisley
12:37 p.m.
New subject: PDP-8/E Top Cover
On Jul 1, 2007, at 12:48 PM, Todd Paisley wrote:
Were any of the Digital PDPs standardized as far as
the top
covers? I am
looking for a PDP-8/E top cover and wondering if any other model had a
similar top. Thanks.
I've never seen that cover design on any other DEC machine. The 8/
e top cover is designed to fit around the power supply...not very
generic.
-Dave
--
Dave McGuire
Port Charlotte, FL
2:56 p.m.
New subject: PDP-8/E Top Cover
On 01/07/2007 17:48, Todd Paisley wrote:
Were any of the Digital PDPs standardized as far as
the top covers? I am
looking for a PDP-8/E top cover and wondering if any other model had a
similar top. Thanks.
I don't know of any other machine that used the same cover, but I find
mine a bit awkward , so instead I have a cover made out of a folded
piece of transparent polycarbonate. Looks good at exhibitions :-)
--
Pete Peter Turnbull
Network Manager
University of York
3:17 p.m.
New subject: PDP-8/E Top Cover
> Were any of the Digital PDPs standardized as far
as the top covers? I
am
looking for a
PDP-8/E top cover and wondering if any other model had a
similar top. Thanks.
I don't know of any other machine that used the same cover, but I find
mine a bit awkward , so instead I have a cover made out of a folded
piece of transparent polycarbonate. Looks good at exhibitions :-)
4:10 p.m.
New subject: PDP-8/E Top Cover
On 01/07/2007 23:17, Todd Paisley wrote:
When I got it, it had the normal metal cover, but the foam glued to the
inside to press on the boards, had gone the way of all computer foam, so
I had to replace it.
The polycarbonate cover was cut from a larger piece on the occasion of
an exhibition at the University. I had the machine running a simple
demo, and the cover was off so students could see the boards and I could
point out the major parts. It's rather fiddly to keep putting the cover
on and taking it off, however the laboratory superintendent was a bit
concerned about students poking their fingers in (or dropping debris) so
he found this large sheet of pre-folded polycarb, which he donated. A
little extra work after the exhibition made it a better fit, and added
ventilation, so I kept it that way.
--
Pete Peter Turnbull
Network Manager
University of York
I don't
know of any other machine that used the same cover, but I find
mine a bit awkward , so instead I have a cover made out of a folded
piece of transparent polycarbonate. Looks good at exhibitions :-)
Wow. That that would be really neat! I wonder if yours served the same
purpose when it was new!
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ard＠p850ug1.demon.co.uk -
classiccmp＠memory-alpha.org.uk -
mcguire＠neurotica.com -
paisley＠erols.com -
pete＠dunnington.plus.com -
robert＠irrelevant.com