DATAMATH CALCULATOR MUSEUM
Commodore Minuteman 2 (Version 1)
|Date of introduction:||June 1972||Display technology:||LED-modules|
|New price:||$179.00||Display size:||8|
|Size:|| 6.0" x 3.5" x
153 x 90 x 44 mm3
|Weight:||14.0 ounces, 396 grams||Serial No:||R107202|
|Batteries:||6*AA NiCd||Date of manufacture:||mth 06 year 1972|
|AC-Adapter:|| MM-Type A
7.2V 225mA DC, 7.0V 45mA AC
|Origin of manufacture:||USA|
|Precision:||8||Integrated circuits:||TMS0103, 2*SN75491, 2*SN75492|
|Program steps:||Courtesy of:||Joerg Woerner|
Commodore Business Machines (CBM) introduced with the C110 already in September 1971 their first portable electronic calculator, actually a rebranded Bowmar 901B, better known as Bowmar Brain.
While the C110 was a rather short-lived product, did it pave the way to an incredible success story. Its successor Minuteman 1 was introduced within just a few months and started a completely different design language but still using Bowmar electronics. The next evolution - consequently named Minuteman 2 - replaced first the Bowmar electronics and then the Texas Instruments Klixon™ keyboard with Commodore's own designs. It took another iteration with the Minuteman 2SR to drop even the Texas Instruments calculator chips and replace it with a design from MOS Technology, a company Commodore acquired in October 1976 and fueling in October 1977 a revolution with the PET2001 (Personal Electronic Transactor), the best selling "Personal Computer" of its time.
|C110||September 1971||Bowmar||Bowmar||TI TMS0103||TI Klixon||Monsanto MAN-3A|
|Minuteman 1||January 1972||Commodore||Bowmar||TI TMS0103||TI Klixon||Monsanto MAN-3A|
|TI TMS0103||TI Klixon||Monsanto MAN-3A|
Wild Rover Corp.
|Minuteman 2SR||February 1974||Commodore||Commodore
|MOS MCS2523||HEC MM-4
The next iteration of Commodore's design language was introduced in 1974 with the Minuteman 3 series of calculators.
Dismantling the featured Minuteman 2 (MM.2 Version 1)
manufactured in June 1972 by Commodore reveals a major change compared to its
predecessor MM.1. While the the MM.1 made use of the electronics known from the
Bowmar 901C, uses this MM.2 a printed circuit
board (PCB) with a bold mark reading RAVEN 11870.
The main components of the two calculators are pretty similar but Commodore dropped with the MM.2 the [D] button for the power-saving mode and covered the respective key on the Texas Instruments Klixon™ keyboard with a sticker.
The display module of the MM.2 looks familiar to us, it is still using an array of 9 Monsanto MAN-3A 7-Segment LED modules.
In an additional effort to reduce manufacturing costs of their offerings, Commodore even changed the charger power supply design and replaced the original Bowmar chargers with a much more compact MM-Type A product.
Klixon™ is a trademark of Texas Instruments.
If you have additions to the above article please email: firstname.lastname@example.org.
© Joerg Woerner, October 30, 2021. No reprints without written permission.