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Texas Instruments TMS1040 Product Family

Features

The TMS1040 Product Family is based on the TMS1070 "computer-on-a-chip" introduced in 1974 with the original TMS1000. While the TMS1070 can directly interface with low-voltage Vacuum Fluorescent Displays (VFDs) up to 35 Volts does it still need external resistors and a zener diode to bias the anodes and grids of the display with respect to the filament. The TMS1040 added an extra VPP pin to connect a negative 30 Volts bias voltage for its modified output drivers. With the TMS1070 featuring 11 R Outputs for the Digits, 8 O Outputs for the Segments and 4 K Inputs for the Keyboard, reduced the TMS1040 the number of R Outputs to 9, consequently are all known TMS1040 calculator designs using a 9-digit VF Display.

Family Members and Applications

Type Calculator Application Comments
TMS1042 Canon LD-8s, LD-8Ms, LD-8Rs, Olympia CD45A, Sharp EL-8117K Basic,
Basic Memory
First known TMS1040 calculator application
TMS1043 TI-2550 III, TI-1265, TI-1600, TI-1650 Basic Memory  
TMS1044 Bohsei 1000, Brinlock 806, Privileg 858 MD, Unisonic 1040-1 Basic Memory,
Enhanced-Basic
 
TMS1045 Canon F-31, Canola L813, Toshiba BC-8018B, BC-8111B, BC-8112SL, BC-8112SR, Homeland 8109 Basic Memory,
Enhanced-Basic,
Small Desktop
 

TMS1040 Product Family Portfolio

Texas Instruments offered with most of their TMS1040 designs the calculator manufacturers a flexible menu to pick the desired functionality, meaning the chip would support both combined [C/CE] and [R/CM]/[RCM] keys or separate [C][CE] and [RM][CM] keys and the OEM would chose between them accordingly:

Type - Function Matrix C
CE
C/CE M+
M−
RM
CM
R/CM RCM X<>M X<>Y +/- 1/x x2 x % Δ% PI AM F024
TMS1042 * * * * * *           * *       *  
TMS1043 *   * *       * * * * * *          
TMS1044 * * * * *   * * * * * * * * * * *  
TMS1045 * * * * *   * * * * * * * * * * * *

 

Architecture

  Description Comments
Architecture Single-chip Calculator First Generation Digit Processor
Category Digit Processor 4-bit digits
Related TMS1000 Portfolio
TMS1070

11 digits, External Pull-downs
ROM Size 8,192 Bits 1,024 Words * 4 Bits
RAM Size 256 Bits 4 Registers * 16 Digits
Outputs 9 Digits, 8 Segments External Digit Drivers
Inputs 4 Keyboard
0 Miscellaneous
Digit to Keyboard Scan-Matrix

DCM-50A Platform Compatibility

The Datamath Calculator Museum DCM-50A (Platform) supports the TMS1040 Product Family with the TMS1040 Adapter plugged into the right-most TMS1000 Textool Test Socket set to DCM-50A (TMS1000) mode. Both Characterization of TMS1000 Calculator Circuits and Reverse-engineering of TMS1000 Calculator Circuits is supported by the DCM-50A (TMS1000).

Technical Specifications

Parameter Min Typ Max Unit Comments
VSS   0   V   
VDD -7.5 -9 -10 V  
VPP 0 -26 -30 V Peripheral Powersupply
IDD   6 10 mA 300 kHz, -9V
VOUT 0.3 VPP -35 V Output Voltage
Ext. CK  100   400 kHz Level between VSS and VDD
Int. CK  250 300 350 kHz Rext= 100 kOhm, Cext= 33 pF

Technology

The original TMS1040 was manufactured in a 8 um metal gate PMOS process (metal width = 0.30 mil / 8.0 um, metal spacing = 0.35 mil / 9.0 um, diffusion width = 0.25 mil / 6.0 um, diffusion spacing = 0.35 mil / 9.0 um).
The die size of the TMS1040 is approximately 190 mils * 190 mils / 4.8 mm * 4.8 mm.

Packaging

The TMS1040 uses a 0.4 wide 28-pin SPDIP (Shrink Plastic Dual In-line Package with a 0.07 / 1.778 mm lead pitch).

Pin Configuration

Pin IO Function Pin IO Function
1 O R7 Output 28 O R6 Output
2 O R8 Output 27 O R5 Output
3 V Negative Voltage VDD 26 O R4 Output
4   N.C. 25 O R3 Output
5 I K1 Input 24 O R2 Output
6 I K2 Input 23 O R1 Output
7 I K4 Input 22 O R0 Output
8 I K8 Input 21 V Common Voltage VSS
9 I INIT (Reset) 20 V Common Voltage VPP
10 O O7 Output 19 I OSC2 (Ext. CLK = VSS)
11 O O6 Output  18 I OSC1 (Cext, Rext) or Ext
12 O O5 Output 17 O O0 Output
13 O O4 Output 16 O O1 Output
14 O O3 Output 15 O O2 Output


In a typical calculator application the digits of the display are connected with drivers to the scanning R Outputs, the segments of the display are connected directly or with drivers to the O Outputs making use of the provided 5 to 8 PLA to decode the segments, and the keyboard matrix is connected between the K Inputs and R Outputs.

Example for the TI-2550 III with TMS1043:

Pin IO Function Pin IO Function
1 O Digit driver 8 (MSD) 28 O Digit driver 7
2 O Digit driver 9 (Sign, M, OF) 27 O Digit driver 6
3 V Negative Voltage VDD 26 O Digit driver 5
4   N.C. 25 O Digit driver 4
5 I K1 Input 24 O Digit driver 3
6 I K2 Input 23 O Digit driver 2
7 I K4 Input 22 O Digit driver 1 (LSD)
8 I K8 Input 21 V Common Voltage VSS
9 I INIT (Reset) 20 V Common Voltage VPP
10 O Segment driver DP 19 I OSC2 (Connected to OSC1)
11 O Segment driver G 18 I OSC1 (Connected to OSC2)
12 O Segment driver F 17 O Segment driver A
13 O Segment driver E 16 O Segment driver B
14 O Segment driver D 15 O Segment driver C
The Segment drivers A-G and DP (Decimal Point) are connected to the display in the pictured way. 

Keyboard Scan-Matrix

The keyboards of calculators based on the TMS1040 Product Family consist of an x/y-matrix connected to the R Outputs R0-R8 and the K Inputs K1, K2, K4, and K8 allowing for a maximum of 36 switches or adding a 5th "virtual" K10 Input connected with diodes to K2 and K8 in parallel, allowing for a 9x5 keyboard matrix. Texas Instruments offered with most of their TMS1040 designs the calculator manufacturers a flexible menu to pick the desired functionality, meaning the chips would support both combined [C/CE] and [RM/CM] keys or separate [C][CE] and [RM][CM] keys and the OEM would chose between them accordingly.

Full functionality of the TMS1042NL:

  K1 K2 K4 K8
R0 (D1) 0 6 = RM
R1 (D2) 1 7 M−= RM/CM
R2 (D3) 2 8 M+ RCM
R3 (D4) 3 9 M− CE
R4 (D5) 4 . % C/CE
R5 (D6) 5 x CM C
R6 (D7) + ÷ ×
R7 (D8)        
R8 (D9) [ - AM]      

Notes: [y z] Sliding Switch Function, y Switch open, z Switch closed. [M−=] is only used in Accumulation Memory mode and combines [=] first and [M−] followed

Example for the Canon LD-8s Series with TMS1042NL:

  K1 K2 K4 K8
R0 (D1) 0 6 = RM (2)
R1 (D2) 1 7    
R2 (D3) 2 8 M+= (2) RCM (3)
R3 (D4) 3 9 M−= (2) CI
R4 (D5) 4 .  
R5 (D6) 5 x (1) CM (2) C
R6 (D7) + ÷ ×
R7 (D8)        
R8 (D9) [AM] (3)      

Notes: x(1) Implemented in TMS1042NL but not available on LD-8Rs, x(2) Implemented in TMS1042NL but only available on LS-8Ms, x(3) Implemented in TMS1042NL but only available on LD-8Rs. [AM] implemented with a hard-wired Diode in LD-8Rs only

Example for the Sharp EL-8117K with TMS1042NL:

  K1 K2 K4 K8
R0 (D1) 0 6 =  
R1 (D2) 1 7   RCM
R2 (D3) 2 8 M+  
R3 (D4) 3 9 M−  
R4 (D5) 4 . % C/CE
R5 (D6) 5 x    
R6 (D7) + ÷ ×
R7 (D8)        
R8 (D9)        

Full functionality of the TMS1043NL:

Example for the TI-2550 III with TMS1043NL:

  K1 K2 K4 K8
R0 (D1) CE 0 . =
R1 (D2) 1 2 3 +
R2 (D3) 4 5 6
R3 (D4) 7 8 9 ×
R4 (D5) C +/− % ÷
R5 (D6) CM MR M− M+
R6 (D7) RV x x2 1/x
R7 (D8)        
R8 (D9)        

Full functionality of the TMS1044NL:

  K1 K2 K4 K8 V K10
R0 (D1)   0 6 +/− Δ%
R1 (D2)   1 7 X-Y =
R2 (D3)   2 8 X-M M−
R3 (D4)   3 9 1/x M+
R4 (D5)   4 . x M−=
R5 (D6)   5 PI x2 M+=
R6 (D7)   % CM RM RM/CM
R7 (D8)   + ÷ ×
R8 (D9) [ - AM] CE C/CE C

Notes: [y z] Sliding Switch Function, y Switch open, z Switch closed. K10 is a "virtual" 5th Keyboard Input line connected with two diodes to the K2 and K8 Keyboard Inputs of the TMS1044NL

Example for the Bohsei Model 1000 with TMS1044NL:

  K1 K2 K4 K8 V K10
R0 (D1)   0 6    
R1 (D2)   1 7   =
R2 (D3)   2 8 MX M−
R3 (D4)   3 9 1/X M+
R4 (D5)   4 . x  
R5 (D6)   5 PI    
R6 (D7)   %     R/CM
R7 (D8)   + ÷ ×
R8 (D9)       C/CE  

Example for the Brinlock Model 806 with TMS1044NL:

  K1 K2 K4 K8 V K10
R0 (D1)   0 6    
R1 (D2)   1 7   =
R2 (D3)   2 8   M−
R3 (D4)   3 9   M+
R4 (D5)   4 . x  
R5 (D6)   5      
R6 (D7)   % CM RM  
R7 (D8)   + ÷ ×
R8 (D9)       C/CE  

Example for the Privileg 858 MD with TMS1044NL:

  K1 K2 K4 K8 V K10
R0 (D1)   0 6 +/− Δ%
R1 (D2)   1 7 X-Y =
R2 (D3)   2 8 X-M M−
R3 (D4)   3 9 1/x M+
R4 (D5)   4 . x  
R5 (D6)   5 PI x2  
R6 (D7)   % CM RM  
R7 (D8)   + ÷ ×
R8 (D9) [ - ]   C/CE  

Example for the Unisonic Model 1040-1 with TMS1044NL:

  K1 K2 K4 K8 V K10
R0 (D1)   0 6 +/− GPM
R1 (D2)   1 7 EX =
R2 (D3)   2 8   M−
R3 (D4)   3 9   M+
R4 (D5)   4 . x  
R5 (D6)   5      
R6 (D7)   % CM RM  
R7 (D8)   + ÷ ×
R8 (D9)     CE   C

Full functionality of the TMS1045NL:

  K1 K2 K4 K8 V K10
R0 (D1) [+420F] 0 6 SC M+
R1 (D2) [+420F] 1 7 RV M−=
R2 (D3) [+420F] 2 8   M+=
R3 (D4)   3 9 1/x (
R4 (D5) [+420F] 4 . x )
R5 (D6)   5 PI x2 =
R6 (D7)   CM RM RM/CM
R7 (D8) [Diode] + ÷ ×
R8 (D9) [ - AM]   CI/C  

Example for the Canon F-31 with TMS1045NL:

  K1 K2 K4 K8 V K10
R0 (D1) [+20F] 0 6 SC M+
R1 (D2) [+20F] 1 7 RV  
R2 (D3) [+20F] 2 8    
R3 (D4)   3 9 1/x (
R4 (D5)   4 . x )
R5 (D6)   5 PI x2 =
R6 (D7)   CM RM  
R7 (D8) [Diode] + ÷ ×
R8 (D9)     CI/C  

Example for the Canon L813 with TMS1045NL:

  K1 K2 K4 K8 V K10
R0 (D1) [+420F] 0 6 +/−  
R1 (D2) [+420F] 1 7    
R2 (D3) [+420F] 2 8    
R3 (D4)   3 9    
R4 (D5) [+420F] 4 .    
R5 (D6)   5     =
R6 (D7)   CM RM  
R7 (D8) [Diode] + ÷ ×
R8 (D9) [ - AM]   CI   C

Example for the Canon L813 II with TMS1045NL:

  K1 K2 K4 K8 V K10
R0 (D1) [+420F] 0 6    
R1 (D2) [+420F] 1 7   M−=
R2 (D3) [+420F] 2 8   M+=
R3 (D4)   3 9    
R4 (D5) [+420F] 4 .    
R5 (D6)   5     =
R6 (D7)       RM/CM
R7 (D8) [Diode] + ÷ ×
R8 (D9) [ - AM]   CI   C

Example for the Toshiba BC-8018B, BC-8111B, BC-8112SL and BC-8112SR with TMS1045NL:

  K1 K2 K4 K8 V K10
R0 (D1)   0 6    
R1 (D2)   1 7   M− (1)
R2 (D3)   2 8   M+ (1)
R3 (D4)   3 9 1/x (2) ( (2)
R4 (D5)   4 . x ) (2)
R5 (D6)   5 PI x2 (2) =
R6 (D7)   % CM (1) RM (1)  
R7 (D8)   + ÷ ×
R8 (D9)       C/CE  

Notes: x(1) Implemented in TMS1045NL but not available on BC-8018B, x(2) Implemented in TMS1045NL but only available on BC-8111B, BC-8112SL and BC-8112SR. [y z] Sliding Switch Function, y Switch open, z Switch closed. K10 is a "virtual" 5th Keyboard Input line connected with two diodes to the K2 and K8 Keyboard Inputs of the TMS1045NL

Display

Calculators based on the TMS1040 make use of 9-digit low-voltage VFDs (Vacuum Fluorescent Displays).

horizontal rule

If you have additions to the above datasheet please email: joerg@datamath.org.

Sean Riddle and Joerg Woerner, January 6, 2023. No reprints without written permission.