DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
Texas Instruments SR-22
| Date of introduction: | Sept.11, 1973 | Display technology: | Panaplex II |
| New price: | $350 | Display size: | 10+2 |
| Size: | 9.1" x 6.5" x 2.6" | ||
| Weight: | 1 pound 15 ounces | Serial No: | 5601 |
| Batteries: | BP-200 | Date of manufacture: | year 1973 |
| AC-Adapter: | AC9222 | Origin of manufacture: | USA |
| Precision: | 13 | Integrated circuits: | TMS0207, TMC0323, TMC0404 |
| Memories: | |||
| Program steps: | Courtesy of: | Joerg Woerner | |
| Download manual: | 
(US: 1.527 kB) |
Read
the display of this SR-22 carefully and you notice immediately that this
calculator could perform amazing calculations. It is the only calculator reported to perform
Octal-Decimal-Hexadecimal conversions on the base of floating point numbers.
Later models like the TI Programmer
work only on integer numbers.
The SR-22 is one of the few scientific desktop calculators manufactured by Texas Instruments. It uses a housing with the size of a TI-3500 but the extreme wedge shape of the SR-10.
The same housing was used withthe simpler SR-20 calculator. The TI-450 used the same two-chip calculator brain but lacked the scientific functions. The first usage of the chip set was the TI-4000 and the Canon 121F.
| The displays used in the SR-22 are Panaplex II devices. Keep your fingers away, normal voltage is about 150V. With their orange glow they give a perfect readability even in bright ambient situations. |
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| The printed circuit board (PCB) of the SR-22 showes same age. The driving electronics of the Panaplex II display is formed with individual transistors. |  |
| The calculator uses a calculating circuit with three huge integrated circuits. One is the data-circuit, one the the programm-memory and one the scanning of the display and the keyboard. |  |
| A very astonishing feature is the small row of three LED's (light emitting diodes) to show the selected base. |  |
| A similar housing was used with the scientific desktop calculator SR-20. |  |
Read more about George
Boole, the inventor of the Boolean algebra.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, December 5, 2001. No reprints without written permission.
