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DATAMATH CALCULATOR MUSEUM |
Texas Instruments announced on September 17, 1971 with the TMS1802NC the first commercially available standard calculator building block for a basic four-function calculator on a chip. The TMS1802NC, later renamed to TMS0102, included all control, timing, and output decoders for the display but lacked its drivers. It took another four years until Texas Instruments introduced with the TMS0952 a "real" single-chip design for a more capable basic calculator like the TI-1200.
The TMC0980 family of single-chip calculator circuits was introduced in June 1976 with the two scientific calculators SR-40/TI-30 and the financial calculator Business Analyst of the Majestic product line. The TMC0980 is an extension of the TMS1000 Microcomputer Product Family and allows for highly cost optimized calculators with up to 40 keys and a 9-digit LED Display powered by a 9V battery. Additional cost savings could be achieved by replacing a conventional [ON-OFF] switch with a simple push-button [ON] key. The TMC0980 chip includes 18,432 Bits Read-Only Memory (ROM, 2k*9 Bits) and 576 Bits Random-Access Memory (RAM, 9 Registers * 16 digits), a 4-bit Arithmetic unit, a programmable PLA for segment decoding and both segment and digit drivers for a 9-digit LED Display.
Later calculators in the Majestic line like the TI-55, TI Programmable 57, and The MBA used with the TMC1500 family a much more capable calculator brain doubling the RAM capacity and supporting 12-digit displays.
Due to a flexible design concept with both programmable ROM and segment decoder some design variations of the TMC0980 were introduced and Texas Instruments expanded the product family before finally converting the design with the TP0320 from a 9V metal gate PMOS process to a 3V metal gate CMOS process:
• TMC1980: 9-digit, 7-segment VF-Display, 28-pin Package (Dataman) • TMC0260: 11-digit, 7-segment VF-Display, Thermal Printer Interface, 40-pin Package (TI-5040) • TMC0270: 9-digit, 14-segment VF-Display, 40-pin Package (Speak & Spell) |
Type | Calculator/Product | Application | Comments |
TMC0980/CD9801 | Goulds Pumpulator | Custom Design | ROM code CD9801 |
TMC0980/MP6100 | Ideal Electronic Detective | Toy | ROM code MP6100 |
TMC0980/MP6101B | Parker Brothers Stop Thief | Toy | ROM code MP6101B |
TMC0981 | SR-40, TI-15, TI-30, 30/super, SR-35NC, Silca 48, Studio 29, TI-40, TI professional | Scientific | 8 (5+2) digits |
TMC0982 | Business Analyst, Business Analyst I, Money Manager, TI-31, TI-41 | Financial | 8 (5+2) digits |
TMC0983/ZA0675 | TI Programmer | HEX calculator | ROM code ZA0675 |
TMC0984 | TI-33 | Scientific | 3 Mem., 8 (5+2) digits |
TMC0985 | OEM | Scientific | No AOS, 8 (5+2) digits |
Description | Comments | |
Architecture | Single-chip Calculator | Scientific, Financial |
Category | Digit Processor | 4-bit Digits |
Related |
TMC1980 TMC0260 TMC0270 |
7-segment VF-Display 7-segment VF-Display, Printer 14-segment VF-Display |
ROM Size | 18,432 Bits | 2048 Words * 9 Bits |
RAM Size | 576 Bits | 9 Registers * 16 digits |
Outputs | 9 Digits, 8 Segments | Internal Digit and Segment Drivers |
Inputs | 5 Keyboard 1 Clock Mode |
Segment to Keyboard Scan-Matrix |
Item | Min | Typ | Max | Unit | Comments |
VSS | 0 | V | |||
VDD | -9.0 | V | |||
CK | 250 | 350 | 450 | kHz | Internal oscillator |
The TMC0980 was manufactured in a 6 um metal gate PMOS process (metal width = 0.25 mil / 6.0 um, metal spacing = 0.25 mil / 6.0 um, diffusion width = 0.15 mil / 4.0 um, diffusion spacing = 0.30 mil / 8.0 um).
The die size of the TMC0980 is approximately 180 mils * 190 mils / 4.5 mm * 4.9 mm.
The TMC0980 uses a 0.4” wide 28-pin SPDIP (Shrink Plastic Dual In-line Package with a 0.07” / 1.778 mm lead pitch).
Pin | IO | Function | Pin | IO | Function |
1 | O | Digit driver 7 | 28 | O | Digit driver 6 |
2 | O | Digit driver 8 (MSD) | 27 | O | Digit driver 5 |
3 | O | Digit driver 9 (sign) | 26 | O | Digit driver 4 |
4 | V | Substrate (VSS) | 25 | O | Digit driver 3 |
5 | V | Negative Voltage VDD | 24 | O | Digit driver 2 |
6 | I | Keymatrix input 1 | 23 | O | Digit driver 1 (LSD) |
7 | I | Keymatrix input 2 | 22 | n.c. | |
8 | I | Keymatrix input 3 | 21 | n.c. | |
9 | I | Keymatrix input 4 | 20 | V | Positive Voltage VSS |
10 | I | Keymatrix input 8 | 19 | I | Oscillator Mode |
11 | O | Segment driver DP | 18 | O | Segment driver C |
12 | O | Segment driver B | 17 | O | Segment driver E |
13 | O | Segment driver G | 16 | O | Segment driver F |
14 | O | Segment driver D | 15 | O | Segment driver A |
The Segment drivers A-G and DP (Decimal Point) are connected to the display in the pictured way. | ![]() |
The keyboards of all calculators based on the TMC0980 Product Family consist of an x/y-matrix connected to up to seven segment outputs with the top row ([ON] key) connected to VSS and the keymatrix inputs K1, K2, K3, K4, and K8.
Example for the TI-30 with TMC0981:
K4 | K2 | K3 | K1 | K8 | |
VSS | 1/x | x2 | √x | OFF | ON |
Seg. B | INV | sin | cos | tan | DRG |
Seg. C | K | EE | log | lnx | yX |
Seg. D | PI | % | ( | ) | ÷ |
Seg. E | STO | 7 | 8 | 9 | × |
Seg. F | RCL | 4 | 5 | 6 | − |
Seg. G | SUM | 1 | 2 | 3 | + |
Seg. DP | EXC | 0 | . | +/− | = |
Calculators based on the TMC0980 make use of 9-digit LED Displays with common cathode architecture.
If you have additions to the above datasheet please email: joerg@datamath.org.
© Sean Riddle and Joerg Woerner, January 9, 2021. No reprints
without written permission.