Which company is MFR90073? (Manufacturer of TTL chips in 198

[Erik Baigar]

Dear experts!

In an vintage computer restoration project I came accross a couple
of custom chips. They have been made in 1981 and 1982, probably in
the UK for a military application. The circuitry around them is
entirely made from mil spec TTL chips of the 54xx series. My question
would be which company is hidden behind the manufacturer code 90073?

More details on the chips and pictures of them can be found here:

(1) Part No. 214-017, Week 12/1981, picture at

http://www.baigar.de/TornadoComputerUnit/PECchips/214017_MFR90073.jpg
(2) Part No. 214-018, Week 44/1981, picture at

http://www.baigar.de/TornadoComputerUnit/PECchips/214018_MFR90073.jpg
(3) Part No. 214-020, Week 19/1982, picture at

http://www.baigar.de/TornadoComputerUnit/PECchips/214020_MFR90073.jpg
(4) Part No. 339-446, 67 PS 00205, Week 15/1981, picture at

For those interested: The chips where used in a vintage 12bit computer
probably from a radar application. I investigated this and partially
brought it back to life during the past 4 years and now I am curious
what
these chips are doing. Maybe the (1)-(3) are arrays of resistors?

Best regards,

Erik.

 

[Erik Baigar]

Erik Baigar wrote:

http://www.baigar.de/TornadoComputerUnit/PECchips/214020_MFR90073.jpg
(4) Part No. 339-446, 67 PS 00205, Week 15/1981, picture at

Somehow the link got lost, sorry - here it is:

http://www.baigar.de/TornadoComputerUnit/PECchips/339-446_MFR90073_67PS00205.jpg

 

[Franc Zabkar]

On Sat, 07 Jun 2008 21:43:09 +0200, Erik Baigar <erik@baigar.de> put
finger to keyboard and composed:

Dear experts!

In an vintage computer restoration project I came accross a couple
of custom chips. They have been made in 1981 and 1982, probably in
the UK for a military application. The circuitry around them is
entirely made from mil spec TTL chips of the 54xx series. My question
would be which company is hidden behind the manufacturer code 90073?

More details on the chips and pictures of them can be found here:

(1) Part No. 214-017, Week 12/1981, picture at

http://www.baigar.de/TornadoComputerUnit/PECchips/214017_MFR90073.jpg
(2) Part No. 214-018, Week 44/1981, picture at

http://www.baigar.de/TornadoComputerUnit/PECchips/214018_MFR90073.jpg
(3) Part No. 214-020, Week 19/1982, picture at

http://www.baigar.de/TornadoComputerUnit/PECchips/214020_MFR90073.jpg
(4) Part No. 339-446, 67 PS 00205, Week 15/1981, picture at

For those interested: The chips where used in a vintage 12bit computer
probably from a radar application. I investigated this and partially
brought it back to life during the past 4 years and now I am curious
what
these chips are doing. Maybe the (1)-(3) are arrays of resistors?

Best regards,

Erik.

I can't help, but ISTR that Beckman and Allen Bradley made resistor
arrays at around that time. In any case, wouldn't it be relatively
easy to confirm with a multimeter whether your parts were in fact
resistors?

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Erik Baigar]

Marko wrote:

https://www.bpn.gov/bincs/begin_search.asp
90073 is a CAGE code for CMC, probably a mfr or dist. I don't recognize it
anyhow.
Thanks for this hint. I wrote an email to them (custom chips dept) but

did not get an answer so far. Let's give them some more time...

https://www.webflis.dlis.dla.mil/WEBFLIS/pub/pub_search.aspx?niin= this
is the military database. 339-446 doesn't give any results.
Yes I knew the webflis search before and tried the part numbers

there. This black one 339-446 is used in a core memory driver near to
the
transistors driving the hinhibit lines. So I'd guess these beeing
either transistor arrays, diode arrays or resistor arrays. Using a
multimeter and doing some measurements makes the rersistors quite
unlikely.

Erik.

 

[Erik Baigar]

Franc Zabkar wrote:

I can't help, but ISTR that Beckman and Allen Bradley made resistor
arrays at around that time. In any case, wouldn't it be relatively
easy to confirm with a multimeter whether your parts were in fact
resistors?
Thans Franc for this hint. I unmonted the PCBs and tried with a digital

multimeter. The 214-017 indeed is a resistor array containing 12
resistors with 2.2k each. The pin common to all resistors is No 14.
In the application this is connected to +5V and the resistors are used
for pulling up the open collector driven data lines of the 12 bit
machine. There is no resistor present at pin 7. So for this one the
puzzle is solved.

The 214-018 is a resistor array, too. It contains 8 resistors
with 300R each. Two of them are used on the two PCBs holding
the registers of the unit. They seem to be the pull up resistors
for the internal data bus (only 6 resistors are used per array
since each PCB contains 6 bits of the 12 bit length registers).
There are the common pins for the resistors (2,5,9 and 12) which
are all connected to +5V and the resistors are accessible at
pins 1,3,4,6,8,10,11 and 13. Of course I am not able to figure out
which of the common pins is connected to which resistor without
desoldering the chip. But anyhow - this is not important.

The similar looking 214-020 is difficult to measure since the
surrounding circuitry influences the results (I have three instances
of this on in the unit and results differ). If it is a resistor array,
the resistance must be higher than in the 214-017...

Thanks again,

best regards,

Erik.

 

[Erik Baigar]

Marko wrote:

Parts games are so much fun, Hope this helps you, Mark

Thanks Mark - of course this helps. It is always interesting to
learn about new search engines and exchange thoughts!

67PS00205 didn't show up in the search below so evidently the military never
used it, but the first NSN in the list below is 67PS00420 and it is a
Are you sure that EVERY part the military used, shows up there?

I am quite sure, that the unit on my table is of some military
origin (http://www.baigar.de/TornadoComputerUnit/_View1.jpg), but
may have been some type of prototype. On the other hand a serial
number of 129 is a little bit high for a prototype...

Thanks again,

Erik.

 

[Franc Zabkar]

On Thu, 12 Jun 2008 06:27:49 +0200, Erik Baigar <erik@baigar.de> put
finger to keyboard and composed:

So I'd guess these beeing
either transistor arrays, diode arrays or resistor arrays. Using a
multimeter and doing some measurements makes the rersistors quite
unlikely.

Erik.

FWIW, Sprague was manufacturing TND series diode arrays at around that
time:
http://www.datasheetarchive.com/pdf/3439831.pdf

I have a FSA2719M DIP-16 diode array made by Fairchild in 1981:
http://www.datasheetarchive.com/pdf/1421594.pdf

It is equivalent to a TND3600 (manufacturer uncertain, possibly
Sprague, logo is a "2" or "Z" in a circle).

I see Google references to resistor arrays made by Fairchild,
including the RA08 in this 1979 patent:
http://www.freepatentsonline.com/4281662.html

I also have some DIP RC arrays from around that time.

BTW, none of my parts have the "blob" at pin 1.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

 

[Erik Baigar]

....still no hint from CMC apart from the statement, that these
have been made for what is now BAE in Rochester, but since
the unit has been retired a decade ago, I doubt that there
will be any information...


Franc Zabkar wrote:

FWIW, Sprague was manufacturing TND series diode arrays at around that
time:
http://www.datasheetarchive.com/pdf/3439831.pdf

I have a FSA2719M DIP-16 diode array made by Fairchild in 1981:
http://www.datasheetarchive.com/pdf/1421594.pdf

Thanks for these interesting links. I am now quite sure (by measurements
and drawing a little schematic), that the 339-446 is some RCD
network. It is used to connect the open collector output of a
buffer to the pulled up basis of a driver transistor for the
core memories inhibit lines. Unfortunately it is not a simple
diode array because measurements show the diode in the wrong
direction. Maybe it contains Zehner diodes with a capacitor
in parallel. The pinout is as follows:

1,2,15 and 16: Not connected.
3,4: Connected and input1
14,13: Connected and output1
5,6: Connected and input2
11,12: Connected and output2
7,8: Connected and input3
9,10: Connected and output3

So it might well be, that between 3 and 14 there is the Zehner
diode and between 4 and 13 the capacitor and so on...

The second remaining unknown is the 214/020. Here I still have no
guess.

I also have some DIP RC arrays from around that time.
BTW, none of my parts have the "blob" at pin 1.
Maybe the "blob" is not by the manufacturer but has been applied

later by some sort of incoming inspection? At least they have been
applied before the PCBs have been covered by the protective coating
which makes it fun doing measurements on the PCBs...

Thanks again,

Erik.

 

[Erik Baigar]

Erik Baigar wrote:

The second remaining unknown is the 214/020. Here I still have no
guess.
Did more measurements on this one and investigated the circuitry

around these chips. Now it is quite obvious: The 214-020 is a
input frontend containing 5 diodes and 5 pull-down resistors.

I put a summary on all these custom chips on my web page at:
http://www.baigar.de/TornadoComputerUnit/PECchips/PECchips.html

On the 214-020, the common pin is connected to ground and the
resistors act as pull-downs. The input signals of the unit
are applied to the diodes which shift the level 0.7V towards
ground and the unit is listening to the junction between diode
and resistor. Thus the combination increases noise resistance
of the inputs and acts as pull-down...

Thanks for all comments...

Best regards,

Erik.