Texas Instruments TMS0200 Data Chip


Texas Instruments introduced in 1973 with the TI-4000 Desktop calculator a very compact, yet capable product with a 12-digit display as an upgrade option to the TI-3000 and TI-3500 calculators with 8-digit resp. 10-digit displays. The TI-4000 was one of the first applications of TIs TMS0200 Building Blocks for Desktop Calculators, a groundbreaking architecture centered around a Data Chip and various Support ICs:

TMS0200 Data Chip Register Processor with four 16-digit Registers and seven Keyboard Scan inputs
TMS0300 ROM Chip 512*13 Bits Instruction Memory with serial interface to Data Chip and 13-digit display and keyboard scanning, up to 4 ROM Chips
TMC0400 ROM/Register Chip - 512*13 Bits Instruction Memory with parallel interface to ROM Chip and two 16-digit Registers
TMS0220 Printer Chip Interface to two-color Drum Printer Mechanism
TMC0250 Printer/Display Chip Interface to Thermal Printer Mechanism and Dot-Matrix Display

The TMS0200 Data Chip requires in a minimum configuration as used in the TI-4000 a TMS0300 ROM Chip for Program Memory and to scan up to 13 digits of the display.

The TMS0200 is based on the Register Architecture of the TMS0100 single-chip calculator circuit design introduced in September 1971 but expands its Serial-Access Memory from 3 Registers * 13 digits to 4 Registers * 16 digits, outsources the 320*11 Bits Program Memory and display scanning to a TMS300 ROM Chip with a capacity of 512*13 Bits and 13 digits scan outputs and abandons the integrated segment decoder.

Communication between the TMS0200 Data Chip and the other family members of the TMS0200 Building Blocks is realized with multiple means:

4 S-Times Outputs SA, SB, SC, and SD to signal the 16 States of the Instruction Cycle and synchronize Digit Scanning between the TMS0300 ROM Chip (11 digits D2 D12) and TMS0200 Data Chip (4 digits D1, D13 D15)
IRG A and IRG B Inputs to receive the 13-bit Instruction Words from the TMS0300 ROM in two chunks of 6 bits (IRG A B0 B5) and 7 bits (IRG B B6 B12)
4-bit bidirectional I/O Bus I/O 8, I/O 4, I/O 2, and I/O 1 to communicate with the never introduced 10-Register Chips, the two 16-digit Registers of the TMC0400 ROM/Register Chips or the TMS0220 Printer Chip.
   Note: The ROM section of the TMC0400 is fed through its 13-bit parallel connection with the TMS0300 to the TMS0200
CONA Output: Inhibit Increment ROM (Interrupt sequence)
CONB Output: Idle Condition of Data Chip (Idle = Display Mode)
COND Output: Condition Flag
FLG A Output to transmit the Flag register serially
PREG Output: P Register Data Chip addresses ROM
/STB Output as a programmable signal based of D-Times (Display Times, scanning digits)
BUSY Input for slow devices like the Printer Chip

The combination of both its programmability and scalability of the TMS0200 Building Blocks for Desktop Calculators allowed the introduction of some interesting products like the Hexadecimal Calculator/Converter SR-22 bypassing the BCD correction of the ALU (Arithmetic Logic Unit) or the massive Printing Desktop calculator TI-620.

While none of the known products based on the TMS0200 Building Blocks makes fully use of their possibilities like addressing up to 4 ROM chips and up to 16 Register Chips, did the design lay out the architecture of the TMC0500 Building Blocks for Scientific Calculators introduced with the "Slide Rule" calculator SR-50 in January 1974 and leading all the way to the legendary TI Programmable 59 and the amazing SR-60A Prompting Desktop calculator.

QUICK-LINK to TMS0200 Family.

Products and Applications

Only certain Desktop and Scientific Calculators introduced between 1973 and 1974 by Texas Instruments, Canon, Olympia and Teal adopted the TMS0200 Architecture, while the TMC0250 Printer/Display Chip found its way into the wildly successful PC-100 Printer Cradle for the SR-51, SR-52, SR-56, TI-58, TI-58C, and TI-59 calculators and the SR-60 Prompting Calculator.

Family Members and Applications

Type Calculators Function
TMS0201 TI-4000, TI-410, Canon L121F, Canon L1210 Basic Desktop Calculator
Panaplex Display
TMS0202 SR-20 Scientific Desktop Calculator
Panaplex Display
TMS0203 TI-450, TI-500, TI-620, TEAL 6121D, TEAL PM1200, Elite 1202M Basic and Printing Desktop Calculator
Panaplex Display, VF-Display
TMS0206 Olympia CD401A Basic Desktop Calculator
TMS0207 SR-22 Hexadecimal Calculator/Converter
Panaplex Display

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


  Description Comments
Architecture Building Blocks  
Category Register Processor 64-bit registers (16 digits * 4 Bits)
ROM Size not applicable  
RAM Size 256 Bits 4 Registers * 64 Bits

Technical Specifications

Parameter Min Typ Max Unit Comments
VSS +9.2 +10.0 +10.6 V  
VDD   0   V  
VGG -7.2 -7.0 -6.4 V  
PHI1, PHI2 50 250 300 kHz Opposite phases


The TMS0200 was manufactured in a metal gate PMOS process.


The TMS0200 uses a 0.6 wide 40-pin DIP (Dual In-line Package with a 0.1 / 2.54 mm lead pitch).

Pin Configuration

Pin IO Function Pin IO Function
1 O S-Times A 40 V VDD (0 V)
2 O S-Times B 39 V VGG (-7 V)
3 O S-Times C 38 I Clock Input 1
4 O S-Times D 37 I Clock Input 2
5 O Decimal Point 36 IO I/O Bus I/O 8
6 O Comma 35 IO I/O Bus I/O 4
7 O BCD/Binary Out 1 34 IO I/O Bus I/O 2
8 O BCD/Binary Out 2 33 IO I/O Bus I/O 1
9 O BCD/Binary Out 4 32 O Condition Flag
10 O BCD/Binary Out 8 31 O Condition Flag B
11 O Flag Overflow 30 O Condition Flag A
12 O Digit driver 1 (Right) 29 I Busy
13 O Digit driver 15 (Left) 28 I Instruction word B6-B12
14 O Digit driver 14 27 I Instruction word B0-B5
15 O Digit driver 13 26 IO External Access
16 O Progr. Strobe 25 I Keymatrix input T
17 O P Register 24 I Keymatrix input S
18 I Keymatrix input N 23 V VSS (+10 V)
19 I Keymatrix input O 22 I Keymatrix input R
20 I Keymatrix input P 21 I Keymatrix input Q

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If you have additions to the above datasheet please email:

Joerg Woerner, March 5, 2021. No reprints without written permission.