Datasheet or info for Fairchild uA3656D?

[Brent Hilpert]

I (too) can not find a reference for the uA3656 in the Fairchild Full Line Condensed Catalog (1975).

However, I believe Fairchild's naming convention is that "uA..." would indicate analog or interface functionality.

Speculation #1:
  If there are some connections from the uA3656 to the 1101s (or 1702s) (but not pin-for-pin parallelling) it may be a TTL<->MOS sense-amplifier/driver/level-converter. Early MOS memory chips used external drivers/sense amplifiers, and specialised ICs were produced for those functions.

  For example, I found Motorola refs for DS3645/75 (hex 3S latch driver for MOS mem), DS3647/77 (quad 3S MOS mem IO reg), MC3461 (dual NMOS Memory Sense Amp) (from Motorola Linear 1976).

  Perhaps it is from the Motorola DS36.. line, but second-sourced from Fairchild.

Speculation #2:
  An A/D or D/A converter (perhaps connected to the nearby D connector?).


BTW & FWIW:
  On your web page about the AMI S6800 (http://www.classiccmp.org/hp/ami/ami.htm), you wonder what the FCM7002 IC is.
It is a clock/calendar chip, like those used in the 1970s for constructing digital clocks: the FCM7001 (aka CT7001) was a clock/calendar chip with multiplexed 6-digit 7-segment display outputs. If I have it correctly, on the FCM7002 the 7-segment outputs are replaced with BCD outputs. (... built a clock using the 7001, and saw the 7002 on a real-time-clock I/O board for the TI-990 in the late 1970s, must have been rather awkward for the board designers to interface.)


"Joe R." wrote:
> 
>   Does anyone have any information about this IC? I have two of them. I
> found them in the memory section of an Intel 8008 based computer. The other
> RAMs are Intel 1101s so I'm guessing that these are equivelent parts but I
> want to be sure. The date code on these is 7114 and they're white ceramic
> with gold lids and faint grey traces to each leg. Here
> <http://www.classiccmp.org/hp/i8008-1/close-up.jpg> is a picture of the
> board with the two ICs installed. The ICs in the top row are 1702 EPROMs.
> The 1101 RAMs are in the second row. These two parts are the 2nd and 3rd
> parts from the RH end. FWIW I have a 1970 and a 1973 Fairchild catalogs but
> neigher one lists any uA36xx parts.
> 
>     Joe