Canon F-7

Date of introduction:  1974 Display technology:  LED-stick
New price:   Display size:  8 + 2
Size:  7.0" x 3.4" x 1.8"     
Weight:  10.2 ounces Serial No:  503217
Batteries:  4*AA Date of manufacture:  year 1974
AC-Adapter:   Origin of manufacture:  Japan
Precision:  10 Integrated circuits:  Hitachi HD3650, HD3651, HD3653, HD3666 
Memories:  2    
Program steps:   Courtesy of:  Joerg Woerner

The Palmtronic F-7 was introduced shortly after the Texas Instruments SR-50 and uses a very similar calculator architecture developed by Hitachi. Instead the single-chip calculator chips found inside the F-5 and F-6 models, it uses a processing chip (CPU) HD3650 surrounded by a Read Only Memory (ROM) HD3651, a T-CHIP (Timing Chip) HD3653 and the HD3666 labelled PUC. The same CPU was used in the desktop sized Canola F-11 and the metric conversion calculator FC-80.

Comparing the Palmtronic F-7 with the SR-50 gives some differences:

Item SR-50 F-7
Number of keys 40 36
Display organization 10 + 2 8 + 2
Calculating accuracy 13 digits 10 digits
Calculator forensics 9.000005... 8.991...
Number of memories 1 2
Constants and conversions none 20

Once again Texas Instruments demonstrated its capabilities in calculating algorithm. The Canon F-7 looks great but lacks precision. We found similar poor performance with the F-5 and F-2. On the other hand takes the calculation of 69! (1*2*3...*69) with the F-7 only a fraction of time compared to the SR-50. It is easy to understand, with similar calculating performance engineers have to balance between speed and accuracy.

Read more about the successful TMC0501 family introduced by Texas Instruments with the SR-50 and expanded till the TI-59.

Don't miss the first TI-less calculator sold by Canon, the LE-80M.

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If you have additions to the above article please email:

Joerg Woerner, July 2, 2002. No reprints without written permission.