| TI SR-51-II
USA - 1976
Instruments SR-51-II 4477 USA 2016564.
This calculator was historically sandwiched between the SR-51A and the
modern TI-55 calculator. It used already the new housing of the TI-55,
but instead of the One-Chip, One-PCB solution it used a very complex
electronics with stacked IC's and stacked PCB's. Don't underestimate
this pretty calculator."
Courtesy of: Joerg Woerner
The World of XNumber