3 Jul
2009
3 Jul
'09
6:10 a.m.
From: Liam Proven <lproven at gmail.com>
2009/7/1 Rich Alderson <RichA at vulcan.com>:
Ohboy. Can't deny any of your observations, but I though that for a
site from a world that barely knows that anything other than x86
exists or ever has, it wasn't too bad!
The title was disgraceful. I don't mind US sources favouring US
machines but calling it a complete history is akin to the Soviet state
claiming every worthwhile invention was made by their citizens.
From:
Liam Proven
Sent: Tuesday, June 30, 2009 5:00 PM
Tom's Hardware - a popular site for PC
hardware tweakers and
overclockers - has done an ambitious article on the development of
the
mainframe:
It's a little American-centric but it's
not at all bad.
*American*-centric!?! ?How about *IBM*-centric?!?
After the 1960s, the only non-IBM product mentioned is the
(minicomputer)
VAX-11/780. ?(OK, *super*minicomputer, but even so...)
And in the 1960s, the only other DEC product mentioned is *the
PDP-8*????
(with a brushoff for several years of successful sales prior to the
-8, no
less.) ?Another mini, and no acknowledgement of the PDP-10
mainframe on which
the bulk of the development of the modern Internet took place.
It would be nice if they knew what they were talking about.
IMAO,
Rich But don't tell us - tell them, in their comments
boards, or mail the
author.
I did but they can't take criticism and pulled my comments.
Or better still, write a complementary piece - hell,
perhaps we could
do it collectively on the list as a group effort? - and submit it to
Tom's HW as a follow-on, filling in the gaps...?
Yes it would have to be a joint effort. None of us can ever know it
all, but can we cover enough? An approximate count up of 'big computer
list' up to 1980 is about 7 to 8 hundred machines. I think this is too
many. Should we perhaps limit it to production machines made in
quantities of at least, say ten, or a hundred. But then would we want
to omit machines like Atlas? Probably not. Any ideas on a more useful
measure of what should be included?
Roger Holmes.
Who can write only the ICT 1300/1301/1302 series sections, complete
with modern pictures. I've programmed other mainframes IBM 7094/CDC
6600/ICL 1905E/ICL 1904S/CDC SC17/CDC 7600/ICL 1906S but in most cases
never got near them more than once each, and knew very little about
the internal architecture.
10:46 a.m.
New subject: Dynex DE-5020?
Hello, all,
I've recently come across a device that looks like it is some kind of
disk drive test exerciser made by Western Dynex.
It's a small box with toggle switches in two groups. One group has nine
switches labeled in powers of two from 1 to 256. The other group has
five switches that appear to be two-way momentary contact (up|down) that
are labeled BUSY +|BUSY -; DEC/HEAD 1|INC/HEAD 0; INITIAL/BOT
DISK|REPET/TOP DISK; RECYCLE|LOAD REGISTER; LOAD COMMAND|CLEAR
There are no indicator lamps on the device, just the switches.
It has a ribbon cable that comes out of it that terminates in a
paddle-type board that looks suspiciously like the paddle board that
would plug into the drive electronics backplane of a DEC RK05 disk
drive.
I checked BitSavers, and there's no documents for Dynex or Western
Dynex. I did a little searching, and it looks like Western Dynex made
(or OEM'd) disk drives that were similar to the Diablo 30 drives, which
were the basis of the DEC RK05.
So, here's the questions: Does anyone know of this particular tester
device, and can it be used to exercise RK05's. Anyone have any
documentation that might explain how the thing is operated?
Thanks in advance,
Rick Bensene
The Old Calculator Museum
http://oldcalculatormuseum.com
1:47 p.m.
New subject: Dynex DE-5020?
It's a small box with toggle switches in two
groups. One group has nine
switches labeled in powers of two from 1 to 256. The other group has
five switches that appear to be two-way momentary contact (up|down) that
are labeled BUSY +|BUSY -; DEC/HEAD 1|INC/HEAD 0; INITIAL/BOT
DISK|REPET/TOP DISK; RECYCLE|LOAD REGISTER; LOAD COMMAND|CLEAR
'BOT DISK' / 'TOP DISK' suggests it might be an exerciser for one of
those drives with 2 platters, one fixed and the other removable. I used
one years ago that was badged (and maybe made) by Plessey, it linked to
a normal RK11-D controller and appeared as a pair of RK05s.
There are no indicator lamps on the device, just the
switches.
What's inside it? Does it look to be simple (a few SSI TTL chips) or
complicated (lots of TTL, or a microprocessor)?
It has a ribbon cable that comes out of it that terminates in a
paddle-type board that looks suspiciously like the paddle board that
would plug into the drive electronics backplane of a DEC RK05 disk
drive.
I checked BitSavers, and there's no documents for Dynex or Western
Dynex. I did a little searching, and it looks like Western Dynex made
(or OEM'd) disk drives that were similar to the Diablo 30 drives, which
were the basis of the DEC RK05.
Err no. The Riablo 30 is the RK02 (low density) or RK03 (high density).
The RK05 might look the same to software (although there are differences
in the interface, particularly the drive select lines [1]), but internally
it's quite different (the Dioblo 30 uses a permanent magnet DC motor as the
head positioner, I am not joking, the thing's got brushes and a commutator!)
[1] The Diablo 30 has 4 1-of-n select lines. The RK05 can be configured
(by a pin o nthe itnerface connector) to either do that, or to have 3
binary-coded select lines. The RK11-C controller does 1-of-4 select, and
can have up to 4 drives (RK05s or Diablo 30s) on each of 2 cables. The
RK11-D uses binary select lines and can have 8 RK05s ona single cable.
IIRC that Plessey drive I mentioned had a little PCB that plugged into
the RK11-D drive connector containing a decoder chip to turn the 3-bit
bunarly select into 1-of-n select.
My guess is that this is some kind of drive exerciser, possibly to do
repeating seek patterns (like the ones mentioned in the RK05 maintenance
manual) that you use when settign up the postiioner waveforms. But I
don't have the docs.
-tony
3:02 p.m.
New subject: Dynex DE-5020?
> I checked BitSavers, and there's no documents
for Dynex or Western
> Dynex. I did a little searching, and it looks like Western Dynex made
> (or OEM'd) disk drives that were similar to the Diablo 30 drives, which
> were the basis of the DEC RK05.
They built front loading and top loading disc drives, similar to Diablo, Caelus,
and Pertec. I have a manual on the Dynex series 6000 which I'll upload.
8:14 p.m.
Roger Holmes wrote:
>From: Liam
Proven <lproven at gmail.com>
Or better still, write a complementary piece -
hell, perhaps we could
do it collectively on the list as a group effort? - and submit it to
Tom's HW as a follow-on, filling in the gaps...?
Yes it would have to be a joint effort. None of us can ever know it
all, but can we cover enough? An approximate count up of 'big
computer list' up to 1980 is about 7 to 8 hundred machines. I think
this is too many. Should we perhaps limit it to production machines
made in quantities of at least, say ten, or a hundred. But then would
we want to omit machines like Atlas? Probably not. Any ideas on a
more useful measure of what should be included? 
9:07 p.m.
Up to about 1960, most (all?) computers were vacuum
tubes.
There were a few transistor computers from the military, etc. .... there
was also RECOMP, which was a commercially available computer weighing
just 200 lbs. from Autonetics in 1958. I don't know much about its
internals but I assume it used transistors to be that small.
9:30 p.m.
On 3 Jul 2009 at 20:14, Jerome H. Fine wrote:
Just a suggestion. Up to about 1960, most (all?)
computers were
vacuum tubes. You might want to use that for the initial separation
and specify a different set of parameters for vacuum tubes vs
transistors.
...except when they weren't. (e.g. Univac SS80/SS90--only the clock
generator used tubes--all of the computation was magnetic logic,
diodes and transistors). NEAC 1101/1102 (parametrons). There were
certainly others.
--Chuck
4 Jul
4 Jul
10:07 p.m.
Chuck Guzis wrote:
On 3 Jul 2009
at 20:14, Jerome H. Fine wrote:
Just a suggestion. Up to about 1960, most (all?)
computers were
vacuum tubes. You might want to use that for the initial separation
and specify a different set of parameters for vacuum tubes vs
transistors.
...except when they weren't. (e.g. Univac SS80/SS90--only the clock
generator used tubes--all of the computation was magnetic logic,
diodes and transistors). NEAC 1101/1102 (parametrons). There were
certainly others.
10:49 p.m.
On 4 Jul 2009 at 22:07, Jerome H. Fine wrote:
So just pick whichever year that you feel is the
dividing year between
vacuum tube computers and transistor computers. Then see if the
parameters which make a given model of computer significant are the
same or if the parameters change. My guess is that at the very least,
the number produced of any given model of vacuum computer will be
significantly less, on average, than any given model of transistor
computer. I image that other parameters will also change.
I think I understand what you're saying, but the effect's going to be
masked by the gradual growing acceptance of computers in general and
the decreasing recurring cost per unit of commodity parts, such as
core memories and the improvements in components such as solid-state
diodes and printed circuit boards.
It's a tough call. But your point is taken.
--Chuck
5530
days inactive
5532
days old
9 comments
8 participants
participants (8)
-
aek＠bitsavers.org -
ard＠p850ug1.demon.co.uk -
cclist＠sydex.com -
dave.thearchivist＠gmail.com -
evan＠snarc.net -
jhfinedp3k＠compsys.to -
rickb＠bensene.com -
roger.holmes＠microspot.co.uk