Calculators Chips

Canon LE-80R, Commodore 3101, Kings Point EC-8413 , Casio ROOT-8, Casio root 8S

TMC1170NL/ZA0541

Third generation single chip calculators. With the TMS1001 Texas Instruments introduced the first member of the famous TMS1000 Microcomputer family. The chip contains a microcomputer complete with a program ROM having 1,024 8-bit Words; a temporary storage RAM; input (from keypad); output (to control keypad scan and LED display); and an oscillator (clock). The TMS1000 chip was designed to span a range of hand-held calculator products (from four-function up through simple memory calculators). Since the chip had to be customized with the ROM program appropriate to a product, other programmable features were included to improve the chip's flexibility. Today we know 13 different chips used in TI calculators. These chips vary in implementation technology, number of I/O lines, display drive, amount of ROM (up to 26.6k Bits) and amount of RAM (up to 1,280 Bits). Calculator applications range from simple four-function calculators to the 50-step programmable TI-57. As of mid 1979, over 35 million TMS1000 chips were deployed in both calculator and non-calculator applications, establishing the TMS1000 as the computer architecture with the largest installed base. The internal clock rate varies from 200 to 450 kHz, depending on technology. Die photos courtesy of Sean Riddle. RAM-size determination courtesy of Ken Shirriff.

In 1978 Texas Instruments introduced the first CMOS calculator chips based on the TMS1000 Microcomputer family. The TP0320 architecture is similar to the TMC0980 chips introduced two years earlier for the TI-30 calculator. The main difference – beside the manufacturing process – is the permanent connection of the internal memory (12*64 Bits RAM + 64 Bits Display RAM) to the supply voltage. This feature allowed the „Constant Memory“ found on the calculators based on the TP0320 family like the TI-50 or TI-53. Even after you turn off the calculator its user memory is stored inside the chip. The supply current is low enough to buffer the memory more than a year from two small button cells. The program memory with 2k*9 Bits ROM allowed the conversion of most calculating features known from Majestic calculators (Scientific, Statistical and Financial calculator or even Flight computers). Die photo courtesy of Sean Riddle. RAM-size determination courtesy of Ken Shirriff.

Remember that the first LCD-calculators sold by Texas Instruments used foreign calculator chips manufactured by Toshiba. Find more information about them here.

Together with the CMOS process the employees of Texas Instruments changed the nomenclature of the chips. Instead of the leading characters TMS (Texas MOS Standard) or TMC (Texas MOS Custom) the abbreviation TP appeared for the new device families. These Microcomputers got both ROM programmability and Gate programmability (e.g. segment decoder). The derivatives were either numbered like TP0320, TP0321... or got a CD (Custom Design) number, e.g. CD3202.

The TP0320 architecture with only 28-pin housings, 2k*9 Bits ROM and (12+1)*64 Bits RAM limited calculator designs to simple Scientific (TI-50), Statistical (TI-35) and Financial (Business Analyst II) calculators driving displays with only 8 digits (or 5 digits + 2 exponents) resolution. The "programmable" TI-53 stored as much as 32 key entries in the memory, that’s it!Texas Instruments introduced with the TP0455 architecture a new design to overcome these limitations. It is related to the TMS1000 architecture but added time-keeping capabilities, a more flexible display driver and a different RAM architecture with 128*4 Bits capacity. The TP0455 is still gate-programmable. The first use of the TP0455 was the CD4501 design found in the Time Card introduced end of the year 1981. The TI-55 II demonstrated the flexibility of the TP0455 architecture, two chips formed a powerful Master-Slave architecture. The Master uses a 40-pin housing and scans the keyboard, drives a huge display with 8+2 digits and performs the math capabilities. The Slave in the well known 28-pin housing doubles the memory capacity of the calculator. This allows e.g. 56 program steps compared to the 32 steps of the TI-53.The TP0455 design was soon replaced with the TP0456 and most designs were converted. The CD numbers were incremented 50 units to distinguish the difference between TP0455 (e.g. CD4515) and TP0456 e.g. CD4565). The TP0456 seems to be upward compatible to the TP0320, we know with the TI-30 LCD and TI-30-II calculators using either the CD3202 or CD4565 design. Die photo courtesy of Sean Riddle. RAM-size determination courtesy of Ken Shirriff.

 TP0240,TP0300,

TP0301,TP0355