Well for one the PDP-6 was a 36 bit machine that predated the PDP10.
The PDP-7 was an 18bitter, and unix was devoped on it because they had
one and not many other good reasons.
Allison
-----Original Message-----
From: One Without Reason <vance(a)ikickass.org>
To: Tony Duell <ard(a)p850ug1.demon.co.uk>
Cc: classiccmp(a)classiccmp.org <classiccmp(a)classiccmp.org>
Date: Friday, November 30, 2001 12:31 PM
Subject: Re: History of Computing exam question
>
>I'm curious, Tony? Why the PDP-6 and not the PDP-7? Sure, the PDP-6 was
>used in AI development, but UNIX was written on a PDP-7.
>
>Peace... Sridhar
>
>On Thu, 29 Nov 2001, Tony Duell wrote:
>
>> Here's my list. It's a bit disorganised, and doubtless some of the
>> machines shouldn't really be there, but anyway. I am going to assume that
>> this wonderful technology that can grab any machine from the past can
>> also recreate a machine from the blueprints, even if it was never
>> actually made. That way I can have the first machine on my list :
>> <SNIP!>
>
On Nov 19, 21:04, ajp166 wrote:
> I don't remember that foam as being conductive. Most conductive foams
> tend to shred, those bits are not kind to the electronics.
Agreed :-) The brown stuff isn't much nicer after 15-30 years. I suspect
someone before me had replaced foam that lost its resilience, and thought
conductive foam would be better in some way.
> From: Pete Turnbull <pete(a)dunnington.u-net.com>
> >I've been cleaning up my recently-acquired PDP-8/E, and I've had to
remove
> >the plastic foam from the inside of the lid, which was fairly horrible.
> > I'm not sure what best to replace it with
Thanmks to everyone who replied. I'll just use ordinary high-density foam.
It's much cheaper than a couple of square feet of good quality conductive
foam, which would be a bit thin anyway.
--
Pete Peter Turnbull
Network Manager
University of York
On Nov 24, 21:22, Ethan Dicks wrote:
>
> --- ajp166 <ajp166(a)bellatlantic.net> wrote:
> > From: Ben Franchuk <bfranchuk(a)jetnet.ab.ca>
> > >What about using white leds?
> > >Ben Franchuk.
> >
> > Why? Back then when the led mod was common red was the only
> > available visible color for leds. White leds are a bit blue rich
though
> > they would work. One point is that there are some 28 or so leds/lamps
> > and good ones will not be cheap and cleap ones will not be good.
Agreed. The LEDS are water-white plastic, but red-emitting. Each has its
leads cut short, about 1/8" from the body, and a small 430R resistor
soldered to the cathode and a wire (probably the trimmed-off resistor lead)
to the anode. (Is this what some people have described as an "LED module"
or is that something more substantial?) They then fit into the bi-pin lamp
sockets. The resistors look like modern miniature metal film, but could be
20 years old.
Similar red LEDs cost pennies, maybe 10p. 25p - 35p with integral
resistor. Bi-pin bulbs of about the right voltage/current/intensity cost a
bit more, about 50p each here. I did think about white LEDs, but they cost
over ?3 each. As Allison says, I would need 28 (plus a bag of spares if I
use lamps) and white LEDs give off a very cold bluish light, quite unlike
the slightly yellow lamps. I thought about yellow LEDs, but they're much
*too* yellow. Then I thought about pairs of LEDs, but that's just getting
too silly.
> At about $3/each, yes they are expensive, but only slightly more
expensive
> than real DEC lamps. Personally, I'd go with either red LEDs or bulbs,
> since that's what's appropriate for the period.
I think I'll stick with the existing LEDs and maybe "save up my pocket
money" to buy 40 or so bulbs (28 plus a dozen spares).
--
Pete Peter Turnbull
Network Manager
University of York
On Nov 24, 21:03, ajp166 wrote:
> From: Pete Turnbull <pete(a)dunnington.u-net.com>
> >The front bezel (frame round the panel) has been repainted white, and
> the
> >paint has flaked or chipped off in places, to reveal a chipped coat of
> >beige paint. I'd like to refinish and respray it. What's the correct
> >colour?
>
> DEC gray #68 A color close to eggshell toward very light gray.
Sounds like a very pale grey, not quite white? A lot lighter than the
panel on, say, an 11/34, or an 11/03? I'll see what I can find. Thanks!
> >I'm toying with the idea of replacing the LEDs with bi-pin bulbs, as the
> >panel was originally a bulb panel. The resistors for the warm-up
> current
> >have been clipped out. What value should they be?
>
> leave the leds, likely that mod was done very long ago. The lamps
> tended to die too often.
Yes, I'm sure it was done a long time ago, possibly even when the machine
was new. Judging from the date codes on ICs and dates on some boards, it
was made in early 1974.
> >What's J5 (3-pin Mate-N-Lok) on the PSU for?
>
> Power controller.
Are you thinking of the ones on the back (on the outside)? This one is
inside, near the front, and I think Tony's suggestion (for the power fail)
is right.
> >Lastly (for now :-)), which direction should the fans blow?
> Unknown on direction, I think "out". Filter was a layer of foam where
> there
> was one. I have a an 8f so they are somewhat different but the fans blow
> in
> across the cards. The PS in the reaw with its own fan. The 8e has the
> power supply down the left side(facing the front from front) and thefrom
> right
> (input) to left (out through the PS). The power supply will tolerate
> higher temps
> if memory serves than core. Keeping the core cool and at a relatively
> constant temp was the key to stable ops.
In that case, I exercise my right to change my mind, and I think they
probably are the right way round. The air blown out of the PSU isn't very
warm, but it will presumably be warmer when I put lots of cards in and give
it more of a load.
At some point, I would like to try to get the original core working (it
wasn't when I got it). Expect more questions, about debugging 8K core
stacks, since I don't have a printset!
--
Pete Peter Turnbull
Network Manager
University of York
Your are charged with arranging an exhibition to illustrate the history
of computing. Due to a sufficiently advanced technology you can recover
any historical machine or artifact without cost.
List the 20 to 30 systems you would display and briefly explain the
reason for choosing each.
-- hbp : just for fun ;)
At 02:07 PM 11/30/01 -0500, you wrote:
>> I would add: HP2000 timeshare system..widely used, often provided the
>> first exposure to computers that got many of us started in the field.
>
>I *think* I played my first computer game on the HP2000
>(said game paper tape currently being in Jay West's hands
>for his HP2000).
>-dq
Talk about those times... I remember that the ibm 4381
system that we used at the time received batch jobs
>from an apple-II !!!! network! We would write progams
using the UCSD pascal editor and then we could submit them
for batch processing (including those dreaded OS360 jcl commands,
with batch job data indicated by GO SYSIN specs.. argghh).
No wonder I fell in love with UX when I first had access
to it (ca. 1987). So much simpler and logical...
... but I've grown to respect VMS even if I have lots
to learn about it.
--------------------------------------------------------------
Carlos E. Murillo-Sanchez carlos_murillo(a)nospammers.ieee.org
> > I presume that is a typo and it really is an FD-55B. Is it terminated?
>
> I wouldn't bet on it. There is an FD-54B. That Sanyo MBC555 MS-DOS
> machine has a couple of them in it (or at least mine does). I have no
> idea what the difference between the FD-54B and the FD-55B is, though.
Have a likely-dead one of those drives laying around,
should anyone be interested...
-dq
>The mouse looks to be a slightly
>modified version of the "PC Mouse". The neat thing is that it is an
>optical mouse. :-)
I had an optical mouse way back when with my Mac Plus... I bought it as a
replacement for a broken mouse. I think it was made by A+
At the time, I hated it, you needed a special mouse pad for it to work,
and it wasn't as accurate as the Mac Plus mouse, which made it even
harder to draw.
Just one of those things that I found interesting now that optical mice
are all the rage.
-chris
<http://www.mythtech.net>
On November 30, Fred deBros wrote:
> OK, so there are type 4 (UV plus vis light) and type 5 (UV only) sun
> optical mice.
You mean IR, not UV...
> Type 4 mice require a different optical pad than type 5.
> Type 4 mice are tricky because they have to be adjusted to the grid
> (parallel vs perpendicular) in order to work correctly.
> There is a ps file that prints the type 4 mouse pad grid on paper.
> Do I have to laminate that print, or print it on a transparency and glue
> that onto an aluminum foil or print it onto a reflective foil?
>
> Because my printed pad on plain paper don't work with type 4 mice.
>
> Sniff. I wonder why I find so many optical mice in the garbage here.
I've used that ps file with Type 3 mice, and plain paper worked fine.
Not sure what's up with the Type 4 mice.
-Dave
--
Dave McGuire
St. Petersburg, FL
I have recently acquired a "PCjr Mouse" by Mouse Systems, and I am
looking for a device driver for it. The mouse looks to be a slightly
modified version of the "PC Mouse". The neat thing is that it is an
optical mouse. :-)
The standard MS Mouse driver doesn't find the mouse. The "CuteMouse
1.8" driver hangs the machine up. An old (1992) Mouse Systems driver
hangs the machine up too.
The Colorpaint cartridge works with the mouse without a driver, so at
least I know the mouse works. Do I even need a driver? I imagine older
software doesn't need a driver, but newer software would. Then again,
on a machine this old I don't think I have much of a problem. I'd like
to have a working driver that recognizes the mouse, just in case.
Thanks,
Mike
