[sdiy] Wishing for Interdesign.....

[Paul Schreiber]

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.