For the heck of it, I've tried to design an electro-mechanical binary
adder that can automatically do the carry of the one that arises in 1 +
1 = 10. Of course, you reply, "George Stibitz's already did that in
1937 as you see here..."
http://www.toronto-montessori.on.ca/bsutherland/electricity/stibitz.html
But hey: this is retrocomputing, after all, and I'm not trying to
duplicate Stibitz--my aim is to come up with an electro-mechanical
binary adder architecture that's even simpler than his 2 switches, 2
bulbs, 2 batteries, and 2 relays version.
I think I've done it using 3 switches, 4 bulbs, and 1 battery. Yes,
still eight components but because it lacks the relays, I think it's
definitely simpler and therefore a kind of retro-breakthrough. And yes,
mine does carry the one for 1 + 1 = 10. Feel free to try building this
(or better it if you can with even fewer components).
But I do have a stupid question for everyone that exposes the holes in
my education: if my adder can successfully do all of the below
calculations but no more
0 + 0 = 0
0 + 1 = 1
0 + 10 = 10
0 + 11 = 11
1 + 0 = 1
1 + 1 = 10
1 + 10 = 11
10 + 0 = 10
10 + 1 = 11
11 + 0 = 11
have I constructed a 1-bit binary adder or a 2-bit binary adder?
Thanks,
S.F. Hall
Received on Tue Apr 11 2000 - 23:50:48 BST