7 Apr
2005
7 Apr
'05
1:29 p.m.
They were also used in the pdp8/e/f/m.
The processor maintenance manual revealed on page A-10:
Control Input Output
C D Yn
LOW LOW Bn
LOW HIGH Bn
HIGH LOW ~An
HIGH HIGH HIGH
16 15 14 13 12 11 10 9
I--------------------------------I
I Vcc A4 B4 Y4 Y3 B3 A3 C I
DEC 8266 Pinout I
I A1 B1 Y1 Y2 B2 A2 D GND I
I--------------------------------I
1 2 3 4 5 6 7 8
Gerold
Brent Hilpert wrote:
Would someone happen to have a 1970s-era Signetics TTL
handbook in which they could look up some details about the N8266?
I know that it is a quad 2-input multiplexor/selector and I know what the pinout is.
The questions are:
- what is the specific logic functioning of the 2 control inputs?
- is there any inversion in the data path(s)?
From the cross-references I have the 8266
doesn't seem to have made the transition to a 7400 series standard, probably because
it's functioning is a little weird.
They are used in a Wang 520 calculator with the control lines operated in two different
manners. While the intent of the circuitry would seem apparent, the two uses of the
control lines are somewhat idiosyncratic to each other.
(FWIW: the 520 is circa 1972, TTL logic, micro-program architecture, core rope
micro-program store.)