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RPN-12xx... |
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Benoit Maag had the brilliant idea of reusing two classic Texas Instruments calculators, the TI-1200 and the TI-1250, to make new RPN calculators, by replacing the original chip with a reprogrammed electronic chip with a driver.
RPN-1200
Despite a limited number of 19 keys, a scientific RPN calculator was created using a TI-1200, a simple "4 operations" calculator from the 1970s.
The RPN-1200 has trigonometric and logarithmic functions, power, US <-> metric unit conversions, 4-level stack with LASTX, 10 memories (STO / RCL), FIX and SCI modes.
The RPN-1200 is based on a PIC 18F2550 chip with a MAX7219 LED driver as well as a 9V power supply.
RPN-1250
The TI-1250, simple 24-key calculator, made it possible to create the RPN-1250 which is a programmable scientific calculator, similar to an HP-29C.
The RPN-1250 has a volatile memory of 98 program steps and 3 constant memory backup areas.
The RPN-1250 also has trigonometric and logarithmic functions, power, US <-> metric unit conversions, 4-level stack with LASTX, 20 memories (STO / RCL), FIX and SCI modes, 20 labels (LBL, GTO, GSB), 8 tests (X=0, x=y, x<>0, X<>y...).
The RPN-1250 has a PIC 18F2680 chip with a MAX7219 LED driver as well as a 9V power supply.
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