Texas Instruments TMC0541


With the TMC05xx building blocks Texas Instruments created a novel architecture for scalable scientific calculators. The architecture uses minimum a 2 chip design with the Arithmetic chip TMC0501E and the SCOM (scanning read only memory) but was expandable to a maximum of 8 SCOM's, additional RAM as program memory for programmable calculators, additional RAM for general purpose registers and even a chip driving a printer. 

The TMC0541 Constant Read Only Memory CROM consists of 5k*8 preprogrammed program steps and is contained in the interchangable library module of TI-58 and TI-59. Texas Instruments introduced a total of 13 different modules named TMC0541 to TMC0553. Find a list of the modules here. Third party companies added some dozens of different modules, they could be identified with the name TMC0540 and a customer specific ROM code. 

If you own any third party module, write me a short notice. I like to collect the ROM codes for this datasheet. Thanks in advance, Joerg.


TI-58, TI-58C, TI-59

Technical Specification

Item Min Typ Max Unit Comments
VSS   0   V  
VDD -10.5 -10.0 -9.5 V  
VGG -16.3 -15.8 -15.3 V  
PHI1, PHI2   225 230 kHz Opposite phases


The TMC054x uses a standard DIP-8 package.

Pin Description

Pin IO Function Pin IO Function
1 V Negative Voltage VGG 8 V Common Voltage
2 V Negative Voltage VDD 7 I Clock Input 1
3 O Instruction words 6 I Clock Input 2
4 I Calculating status 5 I External access


If you have additions to the above datasheet please email:

Joerg Woerner, February 02, 2001. No reprints without written permission.