Texas Instruments TMC0260


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 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.

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)

The TMC0260 was introduced in June 1978 with the second generation of the TI-5040 Printing Desktop Calculator and replaced the segment and digit drivers for a 9-digit LED Display with high-voltage drivers for an 11-digit VF-Display and integrates an interface for a Thermal Printer. To accommodate these additional features the 28-pin package of the TMC0980 was replaced with a 40-pin package.

Family Members and Applications

Type Calculator Application Comments
TMC0261 TI-5040 (Version 2) Desktop Printing 10-digit display,
12-column printer
TMC0262 TI-5025 Portable Printing 8-digit display,
10-column printer
TMC0263 TI-5135 Desktop Printing 10-digit display,
12-column printer

Note: Learn more about the MOS Numbering System used by Texas Instruments' early MOS Chips.


  Description Comments
Architecture Single-chip Calculator Scientific, Financial
Category Digit Processor 4-bit digits
Related TMC0980
7-segment LED-Display
7-segment VF-Display
14-segment VF-Display
ROM Size 18,432 Bits 2048 Words * 9 Bits
RAM Size 576 Bits 9 Registers * 16 digits
Outputs 11 Digits, 8 Segments Integrated Digit and Segment Drivers
Inputs 5 Keyboard
1 Clock Mode
Segment to Keyboard Scan-Matrix

Technical Specifications

Item Min Typ Max Unit Comments
VSS   0   V   
VDD   -9.0   V   
VBIAS   -22.0   V   
CK  250 350 450 kHz  Internal oscillator       


The TMC0260 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 TMC0260 is approximately 215 mils * 195 mils / 5.5 mm * 5.0 mm.


The TMC0260 uses a 0.6 wide 40-pin DIP (Dual In-line Package with a 0.1 / 2.54 mm lead pitch).

Pin Configuration


The Segment drivers A-G, DP (Decimal Point) and CP (Comma Punctuation) are connected to the display in the pictured way. 

Keyboard Scan-Matrix

The keyboards of all calculators based on the TMC0260 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. 

Display, Printer

Calculators based on the TMC0260 make use of a 9-digit or 11-digit VF-Display and a Thermal Printer with 10 or 12 columns and a 5*7 dots matrix font. 

horizontal rule

If you have additions to the above datasheet please email:

Sean Riddle and Joerg Woerner, April 6, 2021. No reprints without written permission.