4 ms·
One thing nobody talks about is that packaging technology back then was expensive. 4 bits fits into a 16 pin DIP well and cascades well. It is no coincidence
by bsder 4y ago
One thing nobody talks about is that packaging technology back then was expensive.
4 bits fits into a 16 pin DIP well and cascades well. It is no coincidence that the 4004 operates on 4 bit units (BCD was also a factor). The 8008 needed an 18-pin DIP and was still far too constrained.
So, your choice of unit is likely a multiple of 4.
- williamDafoe 4y agoI thought 8008 was a 28-pin DIP and 8080 a 40-pin DIP ...
- bsder 4y agoNope, 8008 was an 18-pin DIP. The 8080 was indeed a 40-pin DIP. However, it still needed something like 3 other support chip to demultiplex everything. It wasn't until the 8085 that you didn't need so much support circuitry.