Product number (P/N): 45,
Keywords/Tags: 45
Date of intro: 1973,
Power: Rechargeable,
Display: Type = Display (LED) (List),
Number of keys: 40,
Classification: / Pocket / RPN (Reverse Polish Notation),
Featuring: Scientific functions, Square root,
Related with: HP_docu: 00045-90300 (Instr.) Owners Handbook 197308; (Docu_Catalogs): EATON: 197512 Christmas,
Known Serial-numbers: 1349S44663 (1349S 44663) | 1349S47321 (1349S 47321) | 1503S08076 (1503S 08076) | 1508S08114 (1508S 08114) (List of all S/Ns from HP_calcs)
Initial Cost Price: USD395.00, Collector value: 8/10,
Courtesy of: CALCUSEUM (Serge DEVIDTS),
Info: ...from PANDEL Ralph:
This calculator has an integrated easter egg in the form of a stopwatch.
The stopwatch had been planned for use in the HP: 55, but the 45 and 55 are using partially the same hardware (The stopwatch in HP 55 is working much more accurate by using an other quartz crystal).
Because of this lack of accuracy, the code to this stopwatch was never exposed in the owner's manual as a user feature.
The code is: shift key, clear, RCL, and then you have to press CHS and 7 and 8 simultaneously. CHS plus 4/5 or plus 1/2 do the same.
Internet: Link-1: THE MUSEUM OF HP CALCULATORS