25 Oct
2018
25 Oct
'18
11:40 a.m.
On Oct 25, 2018, at 1:45 PM, Chuck Guzis via cctalk
<cctalk at classiccmp.org> wrote:
On this subject, is there no interest in serial ALU designs? At one
time, if you wanted a low-cast implementation, that was the way to do
it. Also gives you a leg up on variable word-length designs.
Didn't at least one of the more popular MPU designs employ a serial ALU?
TMS9900?
Serial ALU as a cost saver for low end makes sense in discrete transistor or early SSI
machines, like the PDP-8/L. It's hard to see how it would be useful in MPUs, given
that transistors are so much cheaper there.
The other place I can think of serial arithmetic is in the Orthogonal computer
architecture, sold by Sanders Associates from a 1960s invention by Bill Shooman.
That's an interesting design that does vector arithmetic row-parallel but bit-serial.
Goodyear STARAN used some of those ideas, I believe, though I know very little of the
details.
paul