On Fri, Oct 27, 2017 at 4:13 PM, Brent Hilpert via cctalk
<cctalk at classiccmp.org> wrote:
74S is faster than 74LS, 74LS was combining low power
techniques (which result in loss of speed) with Schottky technology to get some of the
lost speed back, to get a better speed-power product than 'normal' TTL.
Right. My bad there.
The chronological order of development was 74 -->
74H & L --> 74S --> 74LS
I do recall that progression. I've even seen a couple of 74L parts
(and there are more than a couple 74H parts in a 1968 PDP-8)
-ethan