19 Jun
2007
19 Jun
'07
12:21 p.m.
Brent Hilpert wrote:
Before bit-slice chips, the HP 2116 was constructed in
'bit-slice form' from
SSI: 4 boards plugged into the backplane are identical, each board containing
4 bits of the 16-bit ALU and main registers. I expect other SSI-era minis were
done this way. Were any of the early PDP-11's constructed this way, or did the
first PDP-11 use the 74181?
I got looking a schematic of a few months back and the ALU used 7482's -
a 2 bit adder. This was real SSI stuff here, lots of AOI used.
Bitsavers has schematics and they are not too big to download.