APOLLO181: my oldest chip (74S181, data Code: 1973 by Texas Instruments), remarkably still fully functional
Few 1969 TI catalogs list the 74181, but the chip was documented only in the supplemental '70 TTL Catalog
©Fairchild by courtesy of Computer History Museum
The first version of the 9341 ALU was tested using Fairchild's computer-aided design system.
©Texas Instruments TTL ICs Catalog - 1 August 1969
© Texas Instruments and Fairchild Semiconductor
74181 function was described for the first time in 1970 data books:
on the left in March 1970 by Texas Instruments, on the right in October 1970 by Fairchild
© Texas Instruments
Signetics 8260 (datacode:1969): TTL MSI Arithmetic Logic Element. This was the first integrated ALU to be marketed
© Computer World, pg. 42, 5 Ago 1970
Fairchild Semiconductor has announced to the market a low-cost high-speed, 4-bit arithmetic logic unit: the 9340
Texas Instruments is proud to announce to the market
the faster Schottky version: the 74S181, available in mid 1971
Fairchild TTL databook - 9000 serie ©Fairchild
Functions 9341 and 74181 were pin-to-pin equivalent and presented in the same page of a Fairchild databook
CPU board of TI 960B with four 74181 (Computermuseum der Fakultät Informatik - Stuttgart.de)
@ Computermuseum.Informatik.Uni-Stuttgart (modified with enlargement)
The 74181 ALU chips were used in the TTL CPU of many third-generation 1970s minicomputers
Images Copyright by single Manufacturers
PDP 11/44 Data Paths Board with four ALU chips: this was the last PDP-11 processor to be constructed using discrete logic gates
Image credit to Bruce Ray (Wild Hare Computer Systems, Inc.), 2016: inside the NOVA1200 (photo taken especially for APOLLO181 website)
Nova 1200 chassis: the 16K core memory board was removed by Bruce to reveal the CPU board. The 74181 chip is visible on the right
Image copyright by Arnold Reinhold, 2016 [4]
Nova 1200 CPU: as far as I know Data General Nova 1200 was de facto the first commercial computer using the 74181 (datacode: mid 1970)
I have uncapped the 74181 chip to take picture and measure the die size
Click to enlarge
APOLLO181 processor technology belongs to the 3rd Computer Generation
The PERQ workstation, launched in 1980, was probably the last commercial machine based around the 74181 chip.
PERQ workstation 20-bit CPU was built from five 74S181 and one 74S182 carry-lookahead generator chip
© Scuola Radio Elettra - Popular Electronics
RADIORAMA March 1973: MAKE AN ARITHMETIC LOGIC TRAINER. The 74181 was forever popular among hobbyist
Click to enlarge
My model implementation of the 74181 on ISIS Professional Proteus DEMO by Labcenter Electronics Ltd.
The 74181 die measures 0.1 inches and has a density of about 200 components per one-tenth of an inch
Close-up picture I made of the TTL 74181 die taken with a chead photo camera after having uncapped the chip
Image copyright by Ken Shirriff 2017: "Inside the 74181 ALU chip: die photos and reverse engineering" (Permission courtesy of Ken Shirriff)
Ken removed the unique metal layer of the SN74181 and showed that the layout of the die largely matches the gate-diagram of the datasheet.
APOLLO181: my oldest chip (74S181, data Code: 1973 by Texas Instruments), remarkably still fully functional
