This page shows a selection of early portable calculators from a variety of manufacturers. Please refer to the separate brands listings for early calculators from Canon, Sharp, and Hewlett-Packard.
Click on the photos for larger illustrations, or follow the links for further details.
Sanyo Model ICC-1122, S/N 7103240
Functions: ASMD, constant, total, 1 memory
Technology: MOS-LSI, portable (mains power)
Display: 12 digits, fixed decimal, 7-segment neon
Dimensions: 9"W x 5-1/2"D x 2-1/4"H, weight 3 pounds
Manufactured: Sanyo, Osaka Japan, 1971
The Sanyo ICC-1122 is a very early example of MOS-LSI technology in a portable calculator - although the unit could easily be mistaken for a transistor radio. More...
Sanyo Model CX-8001, S/N 87062720
Functions: ASMD, constant
Technology: MOS-LSI, single chip (NEC D271D)
Display: 8 digits, vacuum fluorescent tube
Dimensions: 3-1/4"W x 6"D x 1-1/2"H, weight 11 oz.
Manufactured: Sanyo, Japan, 1973
The Sanyo CX-8001 is a basic eight-digit portable calculator from 1973.
The circuit board uses a D271D processor from NEC, with three other support chips and a host of discrete components. The display uses an eight-digit double-ended vacuum fluorescent tube, with numerals 5mm high. An unusual feature is the use of a pair of (very new) light-emitting diodes for the negative and overflow indications.
The calculator draws about 120-150mA from four disposable AA batteries (about 900mW). It can also be powered from an external 6V adaptor (CU-8001E), via a connecting cord that is fully ten feet long.
Compucorp "Scientist" Model 324G, S/N 4201133
Functions: ASMD, trig, log, special functions, 10 memories
Programming: 2 x 80 steps, all keystrokes, no conditionals
Technology: MOS-LSI by Texas Instruments, MOS memory
Display: 13 significant digits plus 2 exponent, 7-segment neon
Dimensions: 5-1/2"W x 9"D x 3"H, weight 3 pounds (no batteries)
Manufactured: Compucorp USA, 1973.
The Computer Design Corporation of Los Angeles introduced several models of advanced portable calculators in the early 1970s. This Model 324G "Micro Scientist" was a battery-powered portable, programmable, scientific calculator from 1973. More...
Sanyo "Mini", Model CX-6000, S/N 04648108
Functions: ASMD, auto constant
Technology: MOS-LSI, single chip (NEC D234C)
Display: 6/12 digits, vacuum fluorescent tube
Dimensions: 3-1/2"W x 6"D x 1-1/2"H, weight 12 oz.
Manufactured: Sanyo, Japan, 1974
The Sanyo CX-6000 "Mini" is an unusual portable calculator which operates internally with full twelve-digit precision, although it only has a six-digit display. The blue double-arrow key switches between the first and second groups of six digits. A red LED at the lower right of the display lights whenever further digits are available.
The circuit board uses a D234C processor (branded Sanyo, but most probably made by NEC), with about 50 discrete components. The six-digit display uses a double-ended Futaba fluorescent tube.
The calculator has a slide-on cover to protect the keyboard and display, and a carry strap at the rear. There is an instruction sheet with examples inside the cover. Power is supplied from four disposable AA batteries or an external 6V adaptor.
Qualitron Conversion Calculator, Model 1438, S/N 539155
Functions: ASMD, conversion factors
Technology: MOS-LSI (Rockwell A4004PC)
Display: 8 digits, vacuum fluorescent module
Dimensions: 3"W x 5-3/4"D x 1-1/2"H, weight 8 oz.
Manufactured: Qualitron, 1975
The Qualitron 1438 is a basic four-function calculator with a range of pre-programmed conversion factors for distance, mass, volume, and temperature. Two slider switches select land or nautical miles, and US or Imperial volumes. There is provision to enter a single user-defined conversion factor.
The conversion operations are very simple: enter the number, press "CONV", select the present unit, then the required unit.
The circuit board uses a Rockwell A4004PC processor (no relation to the Intel 4004) and a modular power supply, with only about a dozen discrete components. The display uses a 9-digit vacuum fluorescent module. Power is supplied from four disposable AA batteries, or an external 6V adaptor.
