DATAMATH CALCULATOR MUSEUM
Texas Instruments announced on September 17, 1971 with the TMS1802NC the first available standard calculator building block on a chip, it was later renamed into TMS0102. The chip integrates 3,520 Bits Read-Only program Memory (ROM, 320 Words x 11 Bits), a 182-bit Serial-Access Memory (SAM, 3 Registers * 13 Digits, 2 * 13 Bit-Flags) and a decimal arithmetic logic unit as well as control, timing, and output decoders but no drivers for the display. These function blocks of the chip add up to an overall complexity of roughly 5,000 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.
A typical calculator built around the TMS0100 family performs the four basic functions +, −, ×, and ÷ with either Constant or Chain operation. The calculations are done on a floating decimal-point operation but the display of the results could be selected between the floating-point or a fixed-point format. The keyboard scanning, debouncing and encoding in performed inside the chip. The display outputs are fully decoded with a leading zero suppression and multiplexed. The TMS0120 could be called the first single-chip scientific calculator circuit, it uses in the SR-10 "slide Rule" calculator SR-10 "Slide Rule" calculator a novel approach to add to the 8-digit Mantissa in scientific notation a 2-digit Exponent and repurposing the unused Segment H for the minus sign of the Exponent.
Gordon Moore, the co-founder of Fairchild Semiconductor and Intel predicted already in 1965 that the numbers of transistors in Large-scale Integration (LSI) chips would double every year for the next 10 years. In 1975, looking forward to the next decade, he revised the forecast to doubling every two years, a compound annual growth rate (CAGR) of 41%. While Moore did not use empirical evidence in forecasting that the historical trend would continue, his prediction held since 1975 and has since become known as a "law". Main enablers were and are a combination of both reducing the size of the individual components (process shrink) and increasing the chip size (yield improvement). The manufacturing costs of an Integrated Circuit (IC) are calculated with:
• IC cost = (Die cost + Testing cost + Packaging cost) / Final test yield
With the die cost roughly proportional to the die area, testing and packaging costs roughly proportional to the pin count, and the final test yield mostly inverse proportional to the die area, goals are well defined: Keep the die size as small as possible for a set of requirements agreed on. With both ROM (Read-Only Memory) and RWM (Read-Write Memory) sizes the main contributors to the die area of a single-chip calculator circuit and shift-register based data memory (SAM, Serial-Access Memory) of Register Processors denser than RAM (Random-Access Memory) of Digit Processors, Texas Instruments expanded the TMS0100 family two years after its introduction into three different branches:
• TMS0600: Increased ROM (384 Words x 11 Bits), Identical SAM (13 Digits Registers), external display drivers. Process shrink, higher functionality |
• TMS0700: Identical ROM (320 Words x 11 Bits), Identical SAM (13 Digits Registers), external display drivers. Process shrink, identical functionality, cost reduction of IC
• TMS0800: Identical ROM (320 Words x 11 Bits), Reduced SAM (11 Digits Registers), integrated segment drivers. Process shrink, reduced functionality, higher integration
Please notice that the members of the TMS0700 family were still marketed and marked as TMS0100 but both the die and the bottom of the chip package usually sport a TMS0700 marking.
It took about a year till the first copy of the original design appeared. US based company Mostek introduced the MK5020P December 1972.
The TMS0112 was manufactured in Japan by Toshiba, too.
|TMS1802||Sinclair Executive, Texet I, Wireless World Desktop Calculator by Advanced Electronics||[+=],[-=]||8||LED|
|TMS0101||Canon Palmtronic LE-83||[+],[-],[=]||8||LED|
|TMS0103||Bowmar 901B, JCE Mark II, Montgomery Ward P8F||[+=],[-=]||8||LED|
|TMS0105||Canon L800, Privileg 2000||[+=],[-=]||8||LED|
|TMS0106||TI-3500, Canon L100S, Radio Shack EC-2000||[+=],[-=]||10||Panaplex|
|TMS0109||TI-3000, Montgomery Ward P800, D8F, Radio Shack EC-1000||[+=],[-=]||8||Panaplex|
|TMS0117||BCD Coprocessor||10||BCD Output|
|TMS0119||TI-2500, Heathkit IC-2108||[+],[-],[=]||8||LED|
|Architecture||Single-chip Calculator||First Generation|
|Category||Register Processor||44-bit registers (11 digits * 4 Bits)|
Integrated Segment Drivers
|ROM Size||3,520 Bits||320 Words * 11 Bits|
|RAM Size||182 Bits||3 Registers * 13 Digits,
2 * 13 Bit-Flags
|Outputs||11 Digits, 9 Segments||External Digit and Segment Drivers|
|Digit to Keyboard Scan-Matrix|
|CK||100||250||400||kHz||Level between VSS and VGG|
The original TMS0100 was manufactured in a 10 um metal gate PMOS process (metal width = 0.40 mil / 10 um, metal spacing = 0.40 mil / 10 um, diffusion width = 0.40 mil / 10 um, diffusion spacing = 0.4 mil / 10 um).
The die size of the TMS0100 is approximately 230 mils * 230 mils / 5.9 mm * 5.8 mm.
The TMS0100 uses a standard 0.6” wide 28-pin DIP (Dual In-line Package with a 0.1” / 2.54 mm lead pitch).
|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-G/H and DP (Decimal Point) are connected to the display in the pictured way.|
The keyboards of all calculators based on the TMS0100 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 selected with the KP input. The Constant/Chain switch is connected between D10-KQ.
Calculators based on the TMS0100 use all kinds of displays. Texas Instruments introduced together with the calculator chip two pre-configured LED-modules (DIS40, DIS95) based on the TIL360 arrays, the corresponding segment drivers (SN75491) and digit drivers (SN75492). Most early 8-digit designs made use of these parts.
If you have additions to the above datasheet please email: firstname.lastname@example.org.
© Sean Riddle and Joerg Woerner, February 02, 2001. No reprints
without written permission.