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Calculator Integrated Circuits Forensics

"Calculator forensics" is a term coined by Mike Sebastian which seeks to answer the questions of who originally designed a particular calculator's chip set, what features of a particular calculator have been borrowed from earlier designs, and how has calculator technology spread among the manufacturers. Read more about Mike’s results here

Within the Datamath Museum we use the "Calculator forensics" to identify the used calculator chip’s of all featured calculators. Most elder calculators could be opened easily and the chip number identified. However, many calculators cannot be opened without damaging the case or are constructed in such a manner that it is not practical to view the part number. Most modern calculators use „chip-on-board“ designs with the silicon-chip mounted directly on the printed circuit board and a small spot of black resin on top without any part number.

The Forensics Evaluation Algorithm

Observations regarding the embedded algorithms are useful in identifying related calculators. The evaluation algorithm chosen by Mike Sebastian and used in the Datamath Museum is (with the calculator in degrees mode):

arcsin (arccos (arctan (tan (cos (sin (9) ) ) ) ) )

The keystroke sequence (ignoring 2nd, INV, or ARC keys) is typically: 9, sin, cos, tan, arctan, arccos, arcsin. This algorithm usually produces different results on different calculator models (otherwise it would have no value as an evaluation and comparison tool).

The following table joins some information together:

Part number of the chip e.g. TP0324
Custom numbering of the chip e.g. TP0320 [CD3201]
Chip family e.g. TMC0520
Date of introduction of the particular chip
Number of displayed digits e.g. 10 digits
Internal accuracy e.g. 13 digits
Result of the above sequence of trigonometry functions e.g. 9.0000278
Known calculator models with the particular chip e.g. TI-30 STAT, TI-30 GALAXY

Find a list of all known chips manufactured by Texas Instruments here and the calculator chips manufactured by Toshiba here.

Part Number Family Date Digits Accuracy 9-Deg. Known Calculators
TMC0501,521-4 TMC0520 1974 10 13 9.00000527288 SR-50
TMC0501,521-5 TMC0520 1974 10 13 9.000004661314 SR-50, SR-50A
TMC0501,522-5,523-5 TMC0520 1974 10 13 9.000004661314 SR-51, SR-51A
TMC0501,524 TMC0520 1975 10 12/13 9.00000466131(4) SR-52
TMC0501,531 TMC0530 1976 10 13 9.000004661314 SR-50A
TMC0501,534 TMC0530 1976 10 12/13 9.00000466131(4) SR-52
TMC0501,537,538 TMC0530 1976 10 12/13 9.00000466131(4) SR-56
TMC0501,581 TMC0580 1976 10 12 9.00000527288 SR-51-II
TMC0501,582,583 TMC0580 1977 10 13 9.000004661314 TI-58, TI-59, TI-58C, SR-60(A)
TMC0501,582,583,584 TMC0580 1977       SR-60(A)
TMC0501,CD2400,2401 TMC0580 1979       TI-58C
TMS1001 TMS1000 1974 8 8 n.a. SR-16
TMS1016 TMS1000 1975 8 8 n.a. SR-16 II
TMS1111 TMS1100 (1975) 8 10 10.271817 SR-40 Prototype
TMC0980 [CD9801] TMC0980 1980 8 10 n.a. Goulds Pumpulator
TMC0981 TMC0980 1976 8 10 9.177087103 TI-30, SR-40
TMC0982 TMC0980 1976 8 11 n.a. Business Analyst
TMC0983  TMC0980 1978 8 9 n.a. TI Programmer
TMC0984 TMC0980 1976 8 11 9.177087088 TI-33
TMC0985 TMC0980 1977 8 10 9.177087103 Amelia Scientific
TMC1501 TMC1500 1977 8 11 9.0047463834 TI-57 Programmable
TMC1502 TMC1500 1977 10 11 n.a. The MBA
TMC1503 TMC1500 1977 8 11 9.007726486 TI-55, TI-51-III
TMC1983 TMC1980 1978 8 10 9.177087103 TI-45
TP0320 [CD3201] TP0320 1978 8 11 n.a. TI Investment Analyst 
TP0320-4 [CD3202] TP0320 1980 8 11 9.114640577 TI-30-II (1981), TI-30 LCD (1980)
TP0321 TP0320 1978 8 11 9.177087088 TI-50
TP0322 TP0320 1978 8 11 n.a. TI Business Analyst II
TP0323 TP0320 1978 8 11 9.177087088 TI-53
TP0324-4N TP0320 1979 8 11 9.177087103 TI-35 (1979)
TP0324-4NL TP0320 1980 8 11 9.177087088 TI-35 (1980)
TP0326 TP0320 1979        TI-20
TP0327 TP0320 1979      9.177087103 Sharp EL-503
CD2901, CD2902, CD5401, CD5402 TP0485 1982 10 13 9.000000955917 TI-88 
CD4507 TP0456 1982 8 11 9.114640577 TI-40
CD4551,CD4555 TP0456 1981 8 11 9.114640577 TI-54
CD4553,CD4554 TP0456 1983 8 11 n.a. BA-54, BA-55
CD4556,CD4555 TP0456 1981 8 11 9.114640577 TI-55-II, TI-55-III, TI-56
CD4557 TP0456 1982 8 11 9.114640577 TI-30 STAT, TI-35 (1982), TI-35 II
CD4559 TP0456 1982 8 9 n.a. TI Converter
CD4564 TP0456 1982 n.a. LOGpit
CD4565 TP0456 1982 8 11 9.114640577 TI-30-II (1983), TI-30 III, TI-30 LCD (1982)
CD4569 TP0456 1982 8 9 n.a. LCD Programmer
CD4570 TP0456 1982 n.a. Little Professor
CD4571 TP0456 1982 8 11 n.a. BA-35 Student Business Analyst
CD4572,CD4555A TP0456 1982 8 11 9.114640577 TI-57 LCD
CD4805,CD4806 TP0458 1987 10 13 9.00044229369 TI-65
CD4808 TP0458 1987 8 11 9.114640577 TI-30 Galaxy (Italy)
CD4810,CD4811 TP0458 1986 10 13 9.00044229369 TI-62 Galaxy
CD4812 TP0458 1987 10 12 n.a. BA-III
CD4815,CD4614 TP0458 1986 10 13 9.00044229369 TI-60
T3327     1975 8 8 9.148251 Toshiba SC-7100 
T3636     1977 8 9 8.9789682 Toshiba SLC-8300 
PN1033734 aka T3659 or T3669   1977 8 9 8.9789682 Toshiba SLC-8260, early TI-25 
T3734     1978 8 9 8.9789682 later TI-25
T3763   1978 8 9 8.9789682 Toshiba SLC-8261, late TI-25 
T3934S     1980 8 9 8.9789682 Canon F-55S
T3801S     1980 10 11 9.0000278593 Canon F-63, F-72
T3941   1980 8 9 8.9789682 Canon F-42, Radio Shack EC-476,
Toshiba SLC-8280
     1982 8 9 8.9789682 TI-21
T6711   1982 10 11 9.0000278593 Canon F-73
T6755S   1982 10 11 9.0000278593 Toshiba SLC-8310
T6787   1982 10 11 n.a. Canon Financial
T6823   1982 8 9 8.9789682 Canon F-43, F-44, F-45
T6824   1982 8 11 8.9789682 Toshiba SLC-8410, Canon FS-5
T6825     1982 8 9 8.9789682 TI-30 SLR
T6868   1983 10 11 9.0000278593 Canon FP-11P
T6875    1983 10 13 9.000002294775 TI-66 
T6973    1983 8 11 9.0000278593 TI-45 MSP
T6974S     1984 8 11 9.0000278593 TI-30 SLR (2nd), TI-30 SLR+, TI-31, TI-31 Solar, TI-35 Solar, TI-25X, TI-30S
T6975      1984 8 11 9.0000278593 TI-30 Galaxy (Japan)
T6975AS    1984 8 11 9.0000278593 TI-30 Galaxy Solar, TI-35 Galaxy Solar
T7750S   1984 8 11 9.0000278593 Canon F-58
T7767    1985 10 12 8.99999863704 TI-35 PLUS, TI-52
T7768    1985 10 12 8.99999863704 TI-36 Solar, TI-37 Galaxy Solar, TI-52 Solar
T7917    1986 10 13 n.a. TI BA SOLAR
      1987 10 11 9.0000156204 TI-32
T7980S   1987          
T7981S   1987   8 11 9.000052205 Canon FS-400
T7987S    1987           
T7988    1987 10 12 8.99999863704 TI-34
    1987 10 13 n.a. Business Edge
T7942S    1989        e.g. Canon F-802P
    1989 10 12 8.99999863704 SC-10
T9838   1991 10 10 9.000417403 TI-60X
T9948A   1989 10 13 8.999999007884 TI-68 
T6A21     1990            
T6A39    1991           
T6A40    1991            
T6A43    1990 10 13 8.999999616566 TI-81 (early)
T6A43    1992 10 14 8.9999999695957 TI-85
T6A43    1996 10 14 8.9999999695957 TI-86
T6A46    1991             
T6A53    1991 10 13 8.999999883164 BA-II Plus
T6A57    1990 10 12 9.00000229461 TI-36X Solar
T6A58    1990 10 12 9.00000229461 TI-35X 
T6A59    1990 10 12 8.99999864268 Galaxy 40x, 40sx
T6A61    1991 10 12 9.00000229461 TI-30X
T6M19    1991 10 12 8.99999863704  e.g. Canon F-603
T6M27S    1991         
T6M38    1993 10 12 9.00000229461 TI-30X Solar
T6M39S    1992 8 11 n.a. Math Explorer
T6M51    1993 10 13 n.a. Real Estate
T6M53    1995 10 13 8.999999007884 TI-80
     1995 10 12 8.99999864268 Explorer Plus, TI-40 Solar
    1997 10 12 8.99999864268 TI-40 Collège
T6M79     1995 10 12 9.00000229461 TI-30Xa, TI-30Xa Solar, TI-30Xa SE
T6M80(A)     1996 10 12 9.00000229461 TI-30Xa 
TMP0620F     1991 10 13 8.999999007884 TI-67 Galaxy
        1999 10 13 9.000003512065 TI-30X II B/S
       1999 10 13 9.000003512065 TI-34 II, TI-40 Collège II
       2004 10 13 8.999999993942 BA-II Plus Professional
       2005 10 13 9.000001077372 TI-36X II, TI-Collège
       2007 10 13 9.000001077372 TI-30XS MV
       2007 10 14 8.9999999695957 TI-nspire
TI-REF 83PLUSB/TA2   2004 10 14 8.9999999695957 TI-84 Plus, TI-84 Plus S.E.
TI-REF 84PLUSB/TA3   2004 10 14 8.9999999695957 TI-84 Plus, TI-84 Plus S.E.
Z84C00   1993 10 13 8.999999616566 TI-81 (late)
Z84C00   1993 10 14 8.9999999695957 TI-82, TI-83
Z84C00   1999 10 14 8.9999999695957 TI-73, TI-83 Plus
SC414181   1995 10 14 8.9999999817692 TI-92, TI-92 II
MC68EC000   1998 10 14 8.9999999817692 TI-89, TI-89 Titanium, TI-92 Plus

 

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If you have additions to the above article please email: joerg@datamath.org.

© Joerg Woerner, Dec. 12, 2001. No reprints without written permission.