>Are they ALL DX2-50's? I'm looking for a DX-50.
I'll double check, but yeah, I am pretty sure these 4 are DX2-50.
I also have a small stack of 486 CPUs (cpu chip only), and there might be
a regular DX in there (I know there are some SX and DX2's... as well as a
few that the chip is glued to the heatsink, so I'm not sure what they are)
-chris
<http://www.mythtech.net>
>From: "Brian Chase" <vaxzilla(a)jarai.org>
>
>Someone passed this along to me today. It's a current news item, but I
>though it at least tangentially relevant to classiccmp folks. You'll
>get a bang out of this one--quite literally:
>
>-> In September 2002, reports started to surface in the United States
>-> among brand name computer manufacturers that there were problems
>-> with low-ESR aluminum capacitors produced in Taiwan. Apparently, a
>-> poor-quality, water-based electrolyte had been supplied to multiple
>-> manufacturers of low-ESR aluminum electrolytic capacitors in
>-> Taiwan. Our intelligence sources in Taiwan later confirmed that as
>-> many as eleven manufacturers of low-ESR aluminum capacitors in
>-> Taiwan might have been exposed to the poor electrolyte. The
>-> electrolyte, which is a locally produced knock-off of the Japanese
>-> P-50 type water-based system, was produced without the proper
>-> additives required to stave off excess hydrogen gassing. Consequently,
>-> aluminum capacitors produced with the P-50 knock-off tend to fail
>-> catastrophically, by blowing open the rubber seal and leaking liquid
>-> electrolyte on the printed circuit board. These failures reportedly
>-> occur at half the rated lifetime of the components.
>
>http://www.ttiinc.com/MarketEye/zogbi_on_passives_20021014.asp
>
>ObClassicCmp: What are the expected lifespans of various capacitor
>types? I don't have any truly ancient systems, but some of them are
>coming up on the 20 yr mark. When should I look into replacing the
>old caps?
>
>-brian.
>
>
Hi Brian
Not counting defective caps, they can last a long time.
I have an old radio that the electrolytics are still in reasonable
condition and the radio was made in the 50's. I have others
that are only 20 years old and have failed. Switchers put a
higher load on the filter capacitors because of their instantaneous
and rapid demands. These are the most likely applications for
low ESR's. One should check the burst seal and make sure it hasn't
already blown or is bulging.
Electrolytics that have been sitting for several years should
be brought up slowly to reform the surfaces. The best way to do
this is to disconnect and put on a power supply with a high value
current limiting resistor. Many large computer grade capacitors
may have normal leakage in the ma range so choose the resistor
accordingly. Small capacitors in the tens of uF should have
microampere leakage.
Dwight
Hi Pat
The link to the lab stuff was old so I did a little looking
around and found:
http://routh.ee.adfa.edu.au/%7Eirp/Teaching/Control_Theory_2/Labs.html
It shows some uses of the GP-6 for analyzing control
systems.
Dwight
>From: "Patrick Finnegan" <pat(a)purdueriots.com>
>
>On Mon, 4 Nov 2002, Doug Coward wrote:
>
>> You wrote:
>> > One last thing - does anyone have an idea of what the "SW" and "OP" jacks
>> > at the bottom of the front panel are,
>>
>> Here is a quotes from a GP-10 brochure:
>> "The OP termination is the system's mode control bus.
>> For centralized integrator mode operation, the SW
>> switch control is patched to the OP bus."
>>
>> My take on this is that if you are not controlling
>> the operation mode from a digital computer or other
>> external device, then you need to jumper OP to SW
>> for each integrator in order to control the mode
>> from the front panel buttons.
>> IC = Initial Condition mode
>> HD = Hold mode
>> OP = Operate mode
>> RO = Repetitive Operation mode
>
>Ummm, I seem to have an older GP-6 that has no such front-panel switches.
>It just has the 'Y/POT Select', 'X Select' and 'Compute time' knobs on the
>front (along with the 8 coefficient pots). There's also four small
>potentiometers, with a slotted shaft (for using a tweaker screwdriver for
>adjustment) along the bottom of the front (on the banana jack half)
>which are unlabelled.... any ideas what they are for? They seem to be
>missing from the model pictured on COMDYNA's web site.
>
>> > and how to use the multipliers? I
>> > can't quite seem to get them to 'multiply'...
>
>I guess you can attribute my lack of understanding this part to my lack of
>usage of analog computers... sometimes engineers need to be a little more
>reasonable in their descriptions IMHO.
>
>> Here is a quotes from a MICROPATCH brochure:
>> "Two multiplier networks may be arranged as
>> multipliers, dividers, squarers, or square root
>> extractors of input variables. Two attenuator-switch
>> networks are needed to electronically program a
>> multiplier or divider. One output is patched to the
>> "X" terminal; the other is patched to the "Y" terminal.
>
>Ok, got that
>
>> When the network is patched as an input to an
>> operational amplifier that has a resistor as the
>> feedback, the amplifier's output is the product
>> of the input variables. When the network is
>
>Does 'the network' refer to the output of the multiplier ( the terminal
>not labeled 'x' or 'y')? If so, that's what I've been doing...
>
>> patched as the amplifier's feedback, the amplifier
>> output is the quotient of the two input variables."
>
>But I just used up the X and Y inputs, how am I supposed to use the
>multiplier as feedback for the op-amp?
>
>It'd be helpful if someone had an example schematic or block diagram of
>some sort...
>
>Pat
>--
>Purdue Universtiy ITAP/RCS
>Information Technology at Purdue
>Research Computing and Storage
>http://www-rcd.cc.purdue.edu
>
>http://dilbert.com/comics/dilbert/archive/images/dilbert2040637020924.gif
>
>
>
>
Hi
My understanding of the multiply is that you
connect the gray to the input of one of the amps
that show a feedback resistor. The amp inputs are also
gray. You leave all the green leads open. If you
apply a small level to the x and y, the output of
that amp should be the multiply of the x and y.
You can use the pots in the center to create the
small levels used. Remember that there is also
a scale factor involved. K*X*Y= output. I don't
know what the K would be for this setup.
Dwight
>From: "Patrick Finnegan" <pat(a)purdueriots.com>
>
>On Mon, 4 Nov 2002, Doug Coward wrote:
>
>> You wrote:
>> > One last thing - does anyone have an idea of what the "SW" and "OP" jacks
>> > at the bottom of the front panel are,
>>
>> Here is a quotes from a GP-10 brochure:
>> "The OP termination is the system's mode control bus.
>> For centralized integrator mode operation, the SW
>> switch control is patched to the OP bus."
>>
>> My take on this is that if you are not controlling
>> the operation mode from a digital computer or other
>> external device, then you need to jumper OP to SW
>> for each integrator in order to control the mode
>> from the front panel buttons.
>> IC = Initial Condition mode
>> HD = Hold mode
>> OP = Operate mode
>> RO = Repetitive Operation mode
>
>Ummm, I seem to have an older GP-6 that has no such front-panel switches.
>It just has the 'Y/POT Select', 'X Select' and 'Compute time' knobs on the
>front (along with the 8 coefficient pots). There's also four small
>potentiometers, with a slotted shaft (for using a tweaker screwdriver for
>adjustment) along the bottom of the front (on the banana jack half)
>which are unlabelled.... any ideas what they are for? They seem to be
>missing from the model pictured on COMDYNA's web site.
>
>> > and how to use the multipliers? I
>> > can't quite seem to get them to 'multiply'...
>
>I guess you can attribute my lack of understanding this part to my lack of
>usage of analog computers... sometimes engineers need to be a little more
>reasonable in their descriptions IMHO.
>
>> Here is a quotes from a MICROPATCH brochure:
>> "Two multiplier networks may be arranged as
>> multipliers, dividers, squarers, or square root
>> extractors of input variables. Two attenuator-switch
>> networks are needed to electronically program a
>> multiplier or divider. One output is patched to the
>> "X" terminal; the other is patched to the "Y" terminal.
>
>Ok, got that
>
>> When the network is patched as an input to an
>> operational amplifier that has a resistor as the
>> feedback, the amplifier's output is the product
>> of the input variables. When the network is
>
>Does 'the network' refer to the output of the multiplier ( the terminal
>not labeled 'x' or 'y')? If so, that's what I've been doing...
>
>> patched as the amplifier's feedback, the amplifier
>> output is the quotient of the two input variables."
>
>But I just used up the X and Y inputs, how am I supposed to use the
>multiplier as feedback for the op-amp?
>
>It'd be helpful if someone had an example schematic or block diagram of
>some sort...
>
>Pat
>--
>Purdue Universtiy ITAP/RCS
>Information Technology at Purdue
>Research Computing and Storage
>http://www-rcd.cc.purdue.edu
>
>http://dilbert.com/comics/dilbert/archive/images/dilbert2040637020924.gif
>
>
>
>
You wrote:
> One last thing - does anyone have an idea of what the "SW" and "OP" jacks
> at the bottom of the front panel are,
Here is a quotes from a GP-10 brochure:
"The OP termination is the system's mode control bus.
For centralized integrator mode operation, the SW
switch control is patched to the OP bus."
My take on this is that if you are not controlling
the operation mode from a digital computer or other
external device, then you need to jumper OP to SW
for each integrator in order to control the mode
>from the front panel buttons.
IC = Initial Condition mode
HD = Hold mode
OP = Operate mode
RO = Repetitive Operation mode
> and how to use the multipliers? I
> can't quite seem to get them to 'multiply'...
Here is a quotes from a MICROPATCH brochure:
"Two multiplier networks may be arranged as
multipliers, dividers, squarers, or square root
extractors of input variables. Two attenuator-switch
networks are needed to electronically program a
multiplier or divider. One output is patched to the
"X" terminal; the other is patched to the "Y" terminal.
When the network is patched as an input to an
operational amplifier that has a resistor as the
feedback, the amplifier's output is the product
of the input variables. When the network is
patched as the amplifier's feedback, the amplifier
output is the quotient of the two input variables."
--Doug
=========================================
Doug Coward
@ home in Poulsbo, WA
Analog Computer Online Museum and History Center
http://dcoward.best.vwh.net/analog
=========================================
I almost said "Exorbus, Multibus, Aim-65, Oh My!", but I figured most people
wouldn't get it :-D
To those three intrepid individuals who responded to my last "free stuff"
posting (Arcnet/Token Ring stuff), I haven't forgotten you! Give me another
day to sort it out...
OK, the usual rules, I'll decide semi-randomly who gets what in case
multiple people ask for the same thing. I'll take PRIVATE OFF-LIST emails
until the end of the week for those who want stuff. Shipping will be from
USA, ZIP code 01473. You pay shipping, and I'll take PayPal, Money Order,
or check ...
Some of this stuff was donated to me by other listmembers (most notably some
of the EXORbus stuff, I think from Mike D.??, and the AIM-65 was a trade w/
Rich Cini??). If you gave it to me, and want it back, you get top priority,
otherwise it goes to whoever else wants it...
The AIM-65 has been tested and works (with some restrictions described
below), but the Multibus and EXORbus stuff is completely untested ....
AIM-65
- The AIM comes with the external case (not sure if it is original or not),
and photocopies of the manuals. The printer is in bad shape, but I also
have a spare printer that you can swap out. The keyboard is missing a key
(between the "." and right shift), and is a bit flaky (double keypresses,
etc.). The ROM sockets are also corroded, and one is in need of
replacement. There is a full complement of 2114 RAM chips, and all ROM
sockets are full.
MULTIBUS
- Hybricon prototyping board
- Qty. 2 Prototek Wire-Wrapping boards
- Nat'l Semi. BLC-064 64K RAM board -- Missing some RAM chips -- Has 27 x
MM5290J chips
- Intersil MCB 512K Memory Board -- 88 x HM4864-2 chips
- Intel 215G Winchester Controller board -- Has PSBX218A and PSBX217C
daughterboards
EXORBUS
- 20-slot backplane and card cage
- Qty. 2 bus extender boards
- Smoke Signal Broadcasting DCB-4E (floppy Ctrlr? Has FD1791B chip)
- Motorola MEX6820-1 (Dual-PIA I/O board)
- GMS Single Board Computer GMS6506-01-c -- Has 6809 CPU, ports labeled
"I/O", "RS-232", "Printer", "IEEE-488". Also has TMS9914A chip
- Southern Company Services SCSEVDG183 -- Video board? Has CRT5027 and
CRT8002 chips
- Micro-Logus P-VDG SCSEVDG183 -- Similar to above board, but with CRT5037
and CRT8002 chips
- Qty. 2 CMS 9609 MPU Rev. A (6809 CPU 2716 ROMs)
- Qty. 2 Motorola Micro Module 1A CPU boards (6800 CPU, one has 2708 ROMs)
- Qty. 2 Chrislin Industries RAM board -- 32 x 4116 chips, RAM/ROM switch
- Hodge, Taylor, and Associates board -- no markings, 3 x AM2909PC chips, 2
x AM2901BDC chips, 8 x 82S2708 ROMs, signed by "W. Hodge" on the back. All
chips soldered on, no sockets...
- Qty. 2 CMS 9650 Serial I/O board -- 8 x 6850 chips (one has Motorola, one
has AMD)
- CMS 9640 Timer board
- GMS 32K Versatile Memory Board GMS6524-01-B -- Tadiran battery backup,
can hold RAM or ROM, currently has 9 2716 ROMs
- Unknown manufacturer interface board -- Has 2708 ROM, 2 x 6820 chips, a
40-pin connector and a 50-pin connector.
- CMS 9601-501 Utility Buffer/Cable Breakout -- 2 RS-232 ports, not sure
which board it is a companion to....
- CMS 9601-503 Cable Breakout Rev. B -- 8 RS-232 ports, probably goes to one
of the 9650 boards above...
That's it!
Rich B.
_________________________________________________________________
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>From: "Patrick Finnegan" <pat(a)purdueriots.com>
>
>On Sat, 2 Nov 2002, Patrick Finnegan wrote:
>
>> I managed to pick up a COMDYNA GP-6 analog computer a couple days ago out
>> at University Salvage. I initially bought it for its nixie tubes, not
>> knowing what it was, and then was a bit dissatisfied with the fact that
>> they were not in great shape.
>>
>> After taking a few seconds to look at it and try to determine what is was
>> with all the banana jacks on the front, I thought "Hmm, it adds and
>> multiplies... google says 'Analog computer'... Wahooo!!"
>
>More info about the one I have - looks to be an early model - with nixie
>tubes intead of the modern LED voltmeter. Also, the problem with the
>display tubes went away when I reseated the display cards in their
>sockets.
>
>After playing with this little guy, I'm suprised at how stable the
>components are - when I'm not touching anything, there's basicall NO
>jitter on the display. It looks like some component values have
>deteoriated or drifted a bit, but seems in nearly excellent shape. I'm
>about to go out to RatShack so I can get some more banana plugs and
>create some more patch cables (assuming that they still sell those...)
Hi
The absolute voltages read are not an issue because you are looking
for relative changes. Still, the resistors and capacitors on the
patch field need to have tight tolerences to get accurate results.
>
>One last thing - does anyone have an idea of what the "SW" and "OP" jacks
>at the bottom of the front panel are, and how to use the multipliers? I
>can't quite seem to get them to 'multiply'...
The multipliers may be over ranging. These usually only work over
a small range of inputs. It might also be that your unit doesn't
include the multipliers. Most analog computing functions don't
require the nonlinear operation of multipliers and use mostly
integrators and adders.
Did you look at the page: http://www.comdyna.com/gp6panb.htm#MULT ??
It describes the use of the multiplier. It needs to be used in
conjunction with an amplifier and feedback resistor.
You might look at the bouncing ball routines for the EC-1.
It looks like you should have 8 amplifiers. I think this is
enough to do this routine with. I'm not sure if the info for
this is on a web page someplace.
Dwight
>
>Thanks for any info
>
>Pat
>--
>Purdue Universtiy ITAP/RCS
>Information Technology at Purdue
>Research Computing and Storage
>http://www-rcd.cc.purdue.edu
>
>http://dilbert.com/comics/dilbert/archive/images/dilbert2040637020924.gif
>
>
>
>
I came across a site today which provided more information on this critter,
and as Fritz had suggested, it is indeed a TurboDOS machine.. I have a copy
of TurboDOS around, but I don't know if Philips used a custom version or ?
Not to mention that I don't have a clue how I'd copy it, or even what
TurboDOS runs on. Here's the link I found to the info on the P3800:
http://www.digidome.nl/philips1.htm Also, the P4500 is a minicomputer of
some kind, apparently.. Not sure if this was one of the rebranded Four/Phase
machines or not, but I wish I had one : )
Will J
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