[sdiy] First appearance of the CA3080?

[ChristianH]

My guess would be that the chip was prohibitively expensive back then,
and it was more economical to do discrete circuits.
Those were the days...

Unbelievable from today's view, but I know one computer keyboard from
that era where key matrix encoding was done with mechanical levers and a
belt, driven from the PSU fan - and (coming from mechanical calculating
machines) that probably was the more reasonable way, instead of using
those costly semiconductor diodes.

Chris



On Tue, 08 Oct 2013 12:25:29 +0200 Florian Anwander
<fanwander at mnet-online.de> wrote:

> Hello Carsten
> 
> On 08.10.13 11:58 , Carsten Toensmann wrote:
> > 1969 by RCA (Wikipedia)
> Thank you! I should have known, that one might look for that at 
> wikipedia....
> 
> Can some of you imagine, why there was no synth filter until the State 
> Variable Filter in the Oberheim SEM in 1974, which was based on the 
> OTAs? Or were there some earlier OTA filters in Synths?
> 
> Florian