Re: 32bit multiplication using TTL logic

On Fri, 17 Feb 2006 21:47:38 +0000, jwelser wrote:
logjam <grant@xxxxxxxxxxxx> wrote:
: I want to design what would have been a super computer in 1975, using
: parts that would have been "easily" available. Several people have

: Crazy? Remember, a few weeks ago I completed soldering 19,008 LEDs to
: make a display...which I haven't finished yet... (building the drivers)

Yup. Crazy. Nuts. Certifiable. Bonkers. Wacko. Insane. ;-P
Stupid? Remains to be seen. ;-D ;-D ;-D

: One last thought for those of you who, well, you know who you are.
: Idle, what would the power consumption of some 600 odd ICs be? 20ma
: per device? This just might make more heat than a pentium!

: Now...for floating point... ;)

Get the integers going first! ;-)

While some others have suggested changes like using a
carry-lookahead adder for the final carry-propagate adder in the
multiplier, I would suggest that you also look into Booth encoding (the
two techniques can both be used.) ...
[enlightening discussion of carry techniques snipped]

I've drawn a schematic using Xilinx's WebPack, of a 4x4 multiplier:
http://www.abiengr.com/~sysop/images/mult-4x4-sch.gif

The ANDs are just plain ANDs, and the ALU-looking thingies are nothing
but 1-bit full adders.

And I've been procrastinating on doing enough of their tutorials to
figure out how to do the guzintas[1] and the guzoutas[2] and schtuff. ;-)

Cheers!
Rich
[1] Goes Into
[2] Goes [comes] Out Of

.