discrete transistors

From: William Donzelli <william_at_ans.net>
Date: Wed Oct 21 08:08:14 1998

> Yes, and again that proves my point. A discrete transistor based computer
> can not compete with a high-end monolithic microprocessor. The laws of
> physics conspire against it.

Well, I think everyone can agree on that today, or anything past the
80386.
 
> Motorola claims to have started shipping ECL integrated circuits in 1962.
> Why were people still building computers using discrete transistors for
> years after that? Many of the high-end computers used discrete
> implementations of non-saturating logic that was very similar to ECL.

The MECL 1 family dates to the early or mid 1960s, and really was fast for
the time (something like 7 nS tpd average). They came in cans (I do not
know if the DIP was developed yet. By 1969, they were obsolete. I do not
know if any computer used them.

Discrete transistor machines hung on until the late 1960s, simply because
ICs were so darn expensive. At a few dollars per _gate_, lots of
transistors and all of the board real estate starts to look good.

William Donzelli
william_at_ans.net
Received on Wed Oct 21 1998 - 08:08:14 BST