[time-nuts] 5370A/B Problems

Mike Feher mfeher at eozinc.com
Tue Sep 13 13:15:08 EDT 2005

As I recall some of the early RCA flat-pack ECL chips actually had studs on
them so they could be attached to something to minimize the thermal
resistance between the package and the board. Often the boards had holes in
them and a heatsink underneath. Yes, they sure did run hot. Of course the
first real 8x8 multiplier by AMD, around 1970, in a 1 inch square and .1
inch thick package draw an amp from a 5 volt supply. We still used a bunch
of them to make larger multipliers to use in our digital filters and FFT
processors. This was before it was called DSP. - Mike  

Mike B. Feher, N4FS
89 Arnold Blvd.
Howell, NJ, 07731

-----Original Message-----
From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
Behalf Of Brian Kirby
Sent: Tuesday, September 13, 2005 12:57 PM
To: Discussion of precise time and frequency measurement
Subject: Re: [time-nuts] 5370A/B Problems

NASA used ECL in a 50 Mb Stat Mux back in the Skylab days.  The muxes 
were in use until about 5 years ago.  These muxes had 4 channels and 
could be run from 0-48 MB on the channels.  These units were large, 
about 3 feet tall by 19 inch rack, and there were muffin fan blowers on 
both ends - like 12 to an end.  They were a pain to troubleshoot, as you 
could only power them on, with the cover on - so the blowers would cool it.

Mike Feher wrote:

>Well, I designed stuff with ECL back in the late 60's and early 70's. At
>time they were really something as they were the fastest logic around. I
>think Sylvania and RCA actually came out with some of the first stuff (in
>flat-packs) and then entered Motorola. - Mike  
>Mike B. Feher, N4FS
>89 Arnold Blvd.
>Howell, NJ, 07731
>-----Original Message-----
>From: time-nuts-bounces at febo.com [mailto:time-nuts-bounces at febo.com] On
>Behalf Of David Forbes
>Sent: Tuesday, September 13, 2005 1:25 AM
>To: Discussion of precise time and frequency measurement
>Subject: Re: [time-nuts] 5370A/B Problems
>At 7:06 AM +0200 9/13/05, Poul-Henning Kamp wrote:
>>In message <a06230901bf4bedd49e4d@[]>, David Forbes writes:
>>>These EECL chips are indeed odd beasts. No data via Google; not in
>>>the Motorola book from 1980; I'd guess that this is a completely
>>>in-house logic family.
>>I don't think that conclusion is justified, ECL logic was always
>>rather special beasts and they were largely superseeded by
>>CMOS by the time the Internet started.
>>Poul-Henning Kamp       | UNIX since Zilog Zeus 3.20
>I reached that conclusion based on the fact that there is no 
>manufacturer or part number given for these chips in the 5370B manual 
>other than HP. The 10K ECL chips in the 5370B parts list are cross 
>referenced to their Motorola part numbers. The ECL 10K and 100K 
>series was produced by several companies; this EECL appears to be 
>unique to HP.
>Has anyone on this list ever heard of EECL logic used anywhere 
>besides HP test equipment? I hadn't heard of it *at all* before 
>today, and I've been designing high speed digital stuff for over 25 

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