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DATAMATH CALCULATOR MUSEUM |
Features |
With the TMS0102 Texas Instruments introduced end of the year 1971 the first available standard calculator building block on a chip. The chip containes 3520-bit read-only program memory, a 182-bit random-access memory and a decimal arithmetic logic unit as well as control, timing, and output decoders but no drivers for the display. This gives an overall complexity of roughly 5000 transistors.
Due to a flexible design concept with both programmable PLA and ROM techniques a lot of design variations appeared. These include two different types of the key-matrix, 8 or 10 digits of 7- or 8-segmented outputs. Even the style of the numbers 4,6 and 9 varied among the family members.
Based on the experience of the TMS0120 developed for the SR-10 some fully floating-point devices derived from the TMS0106 were developed.
Family Members and Usage |
| Type | Calculator | Key-Matrix | Digits | Segment decoder | Timing |
| TMS0123 | [+=],[-=] | 10 | LED | ||
| TMS0126 | Canon LE-80R, Commodore 3101, Privileg 820 | [+=],[-=] | 8 | LED | |
| TMS0127 | Bowmar MX-80 | [+=],[-=] | 10 | LED | |
| TMS0128 | Canon LE-82, JCE Percent | [+=],[-=] | 8 | LED |
Technical Specification |
| Item | Min | Typ | Max | Unit | Comments |
| VSS | 0 | V | |||
| VDD | -8.1 | -7.2 | -6.6 | V | |
| VGG | -13.2 | -14.4 | -16.2 | V | |
| IDD | 17 | 25 | mA | ||
| IGG | 10 | 15 | mA | ||
| CK | 100 | 250 | 400 | kHz | Level between VSS and VGG |
HousingThe TMS0123 uses a
standard DIP-28 package. | |
Pin Description |
| Pin | IO | Function | Pin | IO | Function |
| 1 | I | Clock Input | 28 | V | Common Voltage |
| 2 | I | Keymatrix input P | 27 | I | Keymatrix input Q |
| 3 | O | Digit driver 1 (LSD) | 26 | I | Keymatrix input N |
| 4 | O | Digit driver 2 | 25 | I | Keymatrix input O |
| 5 | O | Digit driver 3 | 24 | O | Segment driver DP |
| 6 | O | Digit driver 4 | 23 | O | Segment driver H |
| 7 | O | Digit driver 5 | 22 | O | Segment driver G |
| 8 | O | Digit driver 6 | 21 | O | Segment driver F |
| 9 | O | Digit driver 7 | 20 | O | Segment driver E |
| 10 | O | Digit driver 8 (MSD8) | 19 | O | Segment driver D |
| 11 | O | Digit driver 9 | 18 | O | Segment driver C |
| 12 | O | Digit driver 10 (MSD10) | 17 | O | Segment driver B |
| 13 | O | Digit driver 11 (OVER) | 16 | O | Segment driver A |
| 14 | V | Negative Voltage VDD | 15 | V | Negative Voltage VGG |
| The Segment drivers A-H and the Decimal point are connected to a display in the pictured way. | ![]() |
Keyboard Scanmatrix |
The keyboards of all calculators based on the TMS0102 family consist of a x/y-matrix connected to the digit driver outputs D1-D11 and the keymatrix inputs KN and KO. In the fixed-point output format mode the position of the decimal point is selcted with the KP input. The Constant/Chain switch is connected between D10-KQ.
TMS0123, 0126 |
TMS0127, 0128 |
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| KN | KO | KP | KQ | KN | KO | KP | KQ | ||
| D1 | 1 | x2 | D1 | 1 | 0/00 | 1 | |||
| D2 | 2 | * | D2 | 2 | * | 2 | |||
| D3 | 3 | : | D3 | 3 | : | 3 | |||
| D4 | 4 | srq(x) | D4 | 4 | % | 4 | |||
| D5 | 5 | += | D5 | 5 | += | 5 | |||
| D6 | 6 | -= | D6 | 6 | -= | 6 | |||
| D7 | 7 | +/- | D7 | 7 | 00 | 7 | |||
| D8 | 8 | D8 | 8 | A/D | (8) | ||||
| D9 | 9 | . | D9 | 9 | . | (9) | |||
| D10 | 0 | CE | K | D10 | 0 | CE | 0 | K | |
| D11 | C | D11 | C | ||||||
Display |
Calculators based on the TMS0102 use all kinds of displays. Texas Instruments introduced together with the calculator chip two pre-configured LED-moduled (DIS40, DIS95) based on the TIL360 arrays ,the corresponding segment drivers (SN75491) and digit drivers (SN75492). Most designs make use of these parts.
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If you have additions to the above datasheet please email: joerg@datamath.org.
© Joerg Woerner, February 02, 2001. No reprints
without written permission.