[sdiy] Wishing for Interdesign.....

[phillip m gallo]

Back in the early '80's i was on a team that developed 4 chips using
Ferranti's Interdesign Gate Arrays.  It was my job to "lay in the metal".
We had good luck with result as there development support was very good.  I
also found there implementation of "pinch resistors" very enlightening.

The process had it's limitations but was very hands on.

regards,
p


-----Original Message-----
From: owner-synth-diy at dropmix.xs4all.nl
[mailto:owner-synth-diy at dropmix.xs4all.nl]On Behalf Of Paul Schreiber
Sent: Friday, May 27, 2005 8:38 AM
To: karl dalen; Colin f; synth-diy at dropmix.xs4all.nl
Subject: [sdiy] Wishing for Interdesign.....


Interdesign was exactly what we need now: a generic "500-in-1" (Radio Shack
reference) array of generic analog "building blocks" on 1 die. You used a
2-color pencil (really!) and drew out the "schematic" on a giant 36" x 48"
master template. Then, they added 2 metal layers and you had a custom IC.

The down-side was you had to test them yourself ("No Time to Test
These!"...obscure reference no one under 47yrs old will get)

The cost was low: $750 and that got you like 40 packaged parts! Of which 30
worked :)

In fact, the early CEM chips (3310/20/30/40) are actually Interdesign parts!
The reason: Doug Curtis, the designer, won a magazine contest with them and
as
1st place got 100pcs free. The rest is history.

The later parts (3396, etc) are done on a Doug Curtis designed array (4X
larger
than Interdesign), the fab was AMI. In Doug's office his winning entry is
framed
on the wall.

BTW: Interdesign had GREAT app notes in a 5" ring binder. They may turn up
on
eBay/flea markets. About 8 are by Doug on the OTA gain cell (patent has
expired....hmmmmm.......)

Paul S.

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