DATAMATH  CALCULATOR  MUSEUM

Texas Instruments TMS1070 Product Family

Features

With the original TMS1000 Microcomputer mainly intended for designs using power-hungry LED displays with external display drivers, uses the TMS1070 redesigned output drivers for the 11 R Outputs (Display Scan) and 8 O Outputs (Segments) that can withstand voltages up to -35 Volts and hence allows direct operation of low-voltage Vacuum Fluorescent Displays (VFDs). All other specifications are identical with the earlier (-15 Volts) standard TMS1000 devices.

Family Members and Applications

Type Calculator Application Comments
TMS1071 TI-2550 II, Homeland 8105, Privileg 861 MD Basic, Memory First TMS1070 application
TMC1073 TI-5100, Panasonic JE-2601U, Toshiba BC-1015 Small Desktop  
TMC1079 Canon MD-8, MD 810 Basic and Small Desktop
Memory, Process
First Two-Line Calculator
TMC1081 Panasonic JE-1604U, JE-170U Small Desktop 16-digit Arithmetic

 

Architecture

  Description Comments
Architecture Single-chip Calculator First Generation Digit Processor
Category Digit Processor 4-bit digits
Related TMS1000 Portfolio
TMS1040

9 digits, Integrated Pull-downs
ROM Size 8,192 Bits 1,024 Words * 4 Bits
RAM Size 256 Bits 4 Registers * 16 Digits
Outputs 11 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 TMS1070 Product Family directly with the TMS1000 Textool Test Socket set to DCM-50A (TMS1000) mode and patching (swapping) of Pin 20 and Pin 21. 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 -14 -15 -17.5 V 15V Series
IDD   6 10 mA 300 kHz, -15V
VOUT 0.3 -30 -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 TMS1070 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 TMS1070 is approximately 210 mils * 210 mils / 5.3 mm * 5.3 mm.

Packaging

The TMS1070 uses either a 0.6 wide 28-pin DIP (Plastic Dual In-line Package with a 0.1 / 2.54 mm lead pitch)
or 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 R8 Output 28 O R7 Output
2 O R9 Output 27 O R6 Output
3 O R10 Output 26 O R5 Output
4 V Negative Voltage VDD 25 O R4 Output
5 I K1 Input 24 O R3 Output
6 I K2 Input 23 O R2 Output
7 I K4 Input 22 O R1 Output
8 I K8 Input 21 V Common Voltage VSS
9 I INIT (Reset) 20 O R0 Output
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 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 II with TMS1071NL:

Pin IO Function Pin IO Function
1 O Digit driver 9 (Sign, M, OF) 28 O Digit driver 8 (MSD)
2 O [F - 2] Switch Scanning 27 O Digit driver 7
3 O Not used 26 O Digit driver 6
4 V Negative Voltage VDD 25 O Digit driver 5
5 I K1 Input 24 O Digit driver 4
6 I K2 Input 23 O Digit driver 3
7 I K4 Input 22 O Digit driver 2
8 I K8 Input 21 O Digit driver 1 (LSD)
9 I INIT (Reset) 20 V Common Voltage VSS
10 O Segment driver DP 19 I OSC2 (Connected to OSC1)
11 O Segment driver G 18 I OSC1 (100 pF, 30 kOhm)
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. 

Example for the TI-5100 with TMC1073NL:

Pin IO Function Pin IO Function
1 O Digit driver 9 28 O Digit driver 8
2 O Digit driver 10 (MSD) 27 O Digit driver 7
3 O Digit driver 11 (Sign, M, OF, CP) 26 O Digit driver 6
4 V Negative Voltage VDD 25 O Digit driver 5
5 I K1 Input 24 O Digit driver 4
6 I K2 Input 23 O Digit driver 3
7 I K4 Input 22 O Digit driver 2
8 I K8 Input 21 O Digit driver 1 (LSD)
9 I INIT (Reset) 20 V Common Voltage VSS
10 O Segment driver DP 19 I OSC2 (Connected to OSC1)
11 O Segment driver G 18 I OSC1 (100 pF, 30 kOhm)
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, DP (Decimal Point) and CP (Comma) are connected to the display in the pictured way. 

Keyboard Scan-Matrix

The keyboards of calculators based on the TMS1070 family consist of an x/y-matrix connected to the R Outputs R0-R10 and the K Inputs K1, K2, K4, and K8 allowing for a maximum of 44 switches.

Example for the TI-2550 II with TMS1071NL:

  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) RV C % ÷
R5 (D6) CM MR M− M+
R6 (D7) (+/−) x x2 1/x
R7 (D8)        
R8 (D9)        
R9 ([F - 1]) [F - 2] ([F - 4])  
R10        

Notes: (x) Implemented in TMS1071NL but not available on TI-2550 II. [y z] Sliding Switch Function, y Switch open, z Switch closed

Example for the TI-5100 with TMC1073NL:

  K1 K2 K4 K8
R0 (D1)       [K - C]
R1 (D2)        
R2 (D3)       [F - 2]
R3 (D4)        
R4 (D5)   (EX) (GPM) (Δ%)
R5 (D6) C/CE CM N %
R6 (D7) 0 1 4 7
R7 (D8)   2 5 8
R8 (D9) . 3 6 9
R9 (D10)   += −= ×
R10 (D11) M+= M−= RM ÷

Notes: (x) Implemented in TMC1073NL but not available on TI-5100. [y z] Sliding Switch Function, y Switch open, z Switch closed

Example for the Canon Palmtronic MD-8 with TMC1079NL:

  K1 K2 K4 K8
R0 (D1)   . 0
R1 (D2)   = RM 1
R2 (D3)   ÷ SC 2
R3 (D4)   × CM 3
R4 (D5)   + x 4
R5 (D6)   M+ 5
R6 (D7)     RV 6
R7 (D8)       7
R8 (D9)     (C) 8
R9 (D10)     CI/C 9
R10 (D11) [M-S-P] [  - AM    

Notes: (x) Implemented in TMC1079NL but not available on Palmtronic MD-8 [y z] Sliding Switch Function, y Switch open, z Switch closed

Example for the Panasonic JE-1604U with TMC1081NL:

  K1 K2 K4 K8
R0 (D1) [F - 0] 0 . =
R1 (D2) ([F - 1]) 1 n %
R2 (D3) [F - 2] 2 RM M+
R3 (D4) [F - 3] 3 CM M−
R4 (D5) [F - 4] 4 +  
R5 (D6) ([F - 5]) 5  
R6 (D7) ([F - 6]) 6 ×  
R7 (D8)   7 ÷  
R8 (D9)   8 Δ%  
R9 (D10)  [▼ - 5/4] 9 GPM CE/C
R10 (D11)        

Notes: (x) Implemented in TMC1081NL but not available on JE-1604U. [y z] Sliding Switch Function, y Switch open, z Switch closed

Display

Calculators based on the TMS1070 make use of 9-digit or 11-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, December 9, 2022. No reprints without written permission.