Hand-held Calculators

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MITS 150
& other MITS calculators

MITS (Micro Instrumentation & Telemetry Systems, Inc.) is famous as the company which in 1975 introduced the Altair 8800, the first mass-marketed home computer, which used an Intel 8080 processor and was the originator of the standard S-100 bus.

Prior to the Altair 8800 MITS introduced a small range of calculators, which could be purchased ready assembled or as a self-assembly kit.  There were several other companies supplying calculator kits, including Heathkit and Sinclair, which gave some cost saving and also the satisfaction of having assembled the calculator oneself.

MITS 150

MITS 150

MITS 150

Distinctive features: One of a number of calculator models manufactured by MITS, the pioneering home computer company.

Technical details:
Display is 8 digits, red LED.

4-functions, %, square, square root.

7.2v (6x AA) rechargeable.

Main integrated circuit - MOS MCS2523 (in this example date coded mid-1973).

83 x 149 x 40 mm (3.3" x 5.9" x 1.6").


Made by Micro Instrumentation & Telemetry Systems, Inc., Albuquerque, New Mexico.

1973 price - US$129.95 assembled or US$99.95 as a kit[1].

With instrucrions & case.

The calculator displayed here has no model number visible (the label on the back is largely erased), and although it came with an instruction manual for the MITS 908M, it is actually a MITS 150. These models are identical except that the 150 has an old-style logo above the display whereas the 908M has "MITS" and the model number, as in the photograph on the front of the instruction book.
Note the large thickness of the calculator (40 mm/1.6") since most of the rear accomodates 6 rechargeable cells.


The 6 rechargeable cells in the rear of the calculator.


The circuit board, with the MOS MCS2523 integrated circuit on the right.

More MITS calculators

The following photographs of MITS calculators were kindly supplied by Steve Shepard, a former employee of MITS.



This model is identical to the MITS 150 shown above, except it has the "MITS 908M" model number above the display.

Price in 1973[2] US$129.95 (assembled) US$99.95 (self-assembly kit).


MITS 941M "Metric Converter"

Has metric conversion functions.

Price in 1973[2] US$149.95 (assembled) US$129.95 (self-assembly kit).

MITS 1212

MITS 1212

A four-function calculator that unusually has a 12-digit LED display.

Price in 1973[3] US$99.95 (assembled).


  1. Popular Electronics, August 1973, p11.
  2. Popular Electronics, November 1973, p28.
  3. Popular Electronics, January 1973, p15.

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Text & photographs copyright, except where stated otherwise, © Nigel Tout 2000-2024.