Texas Instruments TMC0582


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 TMC0582 Double Scanning Read Only Memory DSCOM contains 2.5k*13 instruction memory and 16*16 digits constants.

Additional functions of the TMC0582 include scanning of the display digit driver outputs and the keyboard. 


SR-60A, TI-58, 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 TMC0582 uses a shrinked SDIP-28 package.

Pin Description

Pin IO Function Pin IO Function
1 O Digit driver 15 28 O Digit driver 14
2 V Negative Voltage VGG 27 O Digit driver 13 (OVER)
3 V Negative Voltage VDD 26 O Digit driver 12 (E-MSD)
4 IO SCOM Interface D0 25 O Digit driver 11
5 IO SCOM Interface D1 24 O Digit driver 10
6 IO SCOM Interface D2 23 O Digit driver 9
7 IO SCOM Interface D3 22 O Digit driver 8
8 O Instruction words 21 O Digit driver 7
9 I Calculating status 20 O Digit driver 6
10 I External access 19 O Digit driver 5
11 I Clock Input 2 18 O Digit driver 4
12 I Clock Input 1 17 O Digit driver 3 (M-LSD)
13 V Common Voltage 16 O Digit driver 2 (E-MSD)
14 O Digit driver 0 15 O Digit driver 1 (E-LSD)

Keyboard Scanmatrix

The keyboards of all calculators based on the TMC0501 Arithmetic chip consist of a x/y-matrix connected to the SCOM digit driver outputs and the TMC0501 keymatrix inputs. 

D0 (?)    (?)        
D2    2ND INV lnX   CE  CLR
D3    LRN  X#T  x2    sqrX  1/X
D4    SST  STO RCL    SUM  yX
D5    BST  EE  (    ) :
D6    GTO  7  8    9  *
D7    SBR  4  5  TI58!  6  -
D8    RST  1  2    3  +
D9    R/S  0  .    +/-  =
D10          Card Sense    
D12  (?)   (?)         
D15  (?)    (?)        

Comments: The TI-58 is identified by a diode between D7 - KR, the TI-59 detects the Card Sense switch between D10 - KR. The (?) nodes are used to detect PRINT, PAPER ADVANCE and TRACE on the PC-100A.

If you have additions to the above datasheet please email:

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