TTL homebrew CPUs

[jpero at sympatico.ca]

> > Microcomputing, Kilobaud???) where a fellow gave details about 
> > constructing his own TTL 8080 CPU?  
> 
> I remember a homebrew TTL CPU that used 7489's (16x4 SRAM. Not 16Kx4,
> or 16Mx4, just 16x4!) in a dense array for main memory. Something
> about baby-bottle liners filled with chilled water to keep them cool...
> 
> Would've been mid-70's or earlier. By the mid-70's 2102's were available
> and nobody would've been using 7489's.
> 
> Don't remember which magazine!
> 
> Tim.

7489 you now talking!

What the reason they needed cooling?

I used that in high school to store the data to compare against for 
the 16 x 4 multiple choices via optical sensors.  In theory should 
work this way. Even then the circuits was rather NOISY and 
miss-triggered on everything even the sensors was fighting each 
other! :)   Hehehe.

Cheers, Wizard