"xpyttl" wrote in message
...

Anyway, as we were first looking over the thing, with it's racks of cards
and beautiful, huge electrolytics in the supply, my assistant advisor taps
me on the shoulder and says "come look at this. See that rack of cards
there? I think it's the accumulator."

Sure enough, 18 cards for the accumulator, 18 cards for the program
counter,
18 cards for the M register, one card per bit!

I built my home-brew PDP-8 in a bit-slice way. Each of the main cards had
one bit of the accumulator, memory data register, memory address register
and the "other" register - 12 cards for the main data paths.

As an ancient aside, the "first minicomputer" Whirlwind at MIT was a 16-bit
bit slice machine. There was one whole 6-ft rack for each slice. Thus the
main part of the machine took 16 racks. I never saw the beast, but we (at
USAF Cambridge Research Labs) did do an experiment or two with it driving
our ground to air digital data link. That was in 1953, IIRC. But I was
VERY young back then.....

73 de bob w3otc