DATAMATH  CALCULATOR  MUSEUM

Characterization of Single-chip Calculator Circuits - TMS1040 Family

The DCM-50A Platform supports the Characterization of TMS1040 Devices in its right-most TMS1000 Textool Test Socket with an additional TMS1040 Adapter and the voltages VSS set to 9.5V and VDD/VGG set to -5.5V.

TMS1042NL

Device-under-Test:

Package Markings Top: TMS1042NL, KDSΔ7638
Package Markings Bottom: NONE
Donor Calculator: Canon LD-8Rs, October 1976

Keyboard: The Canon Palmtronic LD-8Rs and its siblings LD-8s and LD-8Ms make use of a keyboard with with conductive rubber switches arranged in an 7*4 matrix with the rows connected to the R0-R6 Outputs (Display Scan) and the columns connected to the K1-K8 Inputs (Keyboard Scan) of the TMS1042NL single-chip calculator circuit. R8 is jumpered for the LD-8Rs with a Diode directly to K1.

Keyboard Matrix of the Canon LD-8s Series:

  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

Display: The Canon LD-8Rs makes use of a 9-digit Itron FG95D6 low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1042NL and biased to approximately -30 Volts with its internal pull-down resistors connected to VPP. We located in a LD-8s manufactured in May 1978 an Itron FG95F6 display while the LD-8Ms is using a similar Futaba 9-ST-11 display.

Display Layout:

Itron FG95D6

The Output Decoder PLA of the TMS1042NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1042 Pin 17 16 15 14 13 12 11 10
TMS1042 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Itron FG95D6 display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1042NL Canon LD-8Rs n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 220 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 18 ICT = 0.12 ms or 0.36 ms
Trailing Digit Blanking = 14 or 2 ICT = 0.28 ms or 0.04 ms
Additional State RX State (Decimal Point) = 26 ICT = 0.52 ms
Display Cycle Time = 224 ICT = 4.48 ms

TMS1042NL

Device-under-Test:

Package Markings Top: TMS1042NL, KDSP 7650
Package Markings Bottom: ⚫JP1042DS, SINGAPORE
Donor Calculator: Sharp EL-8117K, April 1977

Keyboard: The Sharp EL-8117K makes use of a keyboard with triangular snap-action dome switches (United States Patent 3,796,843 from March 12, 1974) arranged in an 7*4 matrix with the rows connected to the R0-R6 Outputs (Display Scan) and the columns connected to the K1-K8 Inputs (Keyboard Scan) of the TMS1042NL single-chip calculator circuit.

Keyboard Matrix of the Sharp EL-8117K:

  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)        

Display: The Sharp EL-8117K makes use of a 9-digit Futaba 9-ST-12 low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1042NL and biased to approximately -28 Volts with its internal pull-down resistors connected to VPP.

Display Layout:

Futaba-9-ST-12

The Output Decoder PLA of the TMS1042NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1042 Pin 17 16 15 14 13 12 11 10
TMS1042 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Futaba 9-ST-12 display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1042NL Sharp EL-8117K n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 220 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 18 ICT = 0.12 ms or 0.36 ms
Trailing Digit Blanking = 14 or 2 ICT = 0.28 ms or 0.04 ms
Additional State RX State (Decimal Point) = 26 ICT = 0.52 ms
Display Cycle Time = 224 ICT = 4.48 ms

TMS1043NL

Device-under-Test:

Package Markings Top: TMS1043NL, ZA0352, AP 7636
Package Markings Bottom: DP1043A, SINGAPORE
Donor Calculator: TI-2550 III, LTA 3776

Keyboard: The TI-2550 III makes use of a keyboard with snap-action dome switches arranged in an 7*4 matrix with the rows connected to the R0-R6 Outputs (Display Scan) and the columns connected to the K1-K8 Inputs (Keyboard Scan) of the TMS1043NL single-chip calculator circuit.

Keyboard Matrix of the TI-2550 III:

  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)        

Display: The TI-2550 III makes use of a 9-digit Itron FG95B1 low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1043NL and biased to approximately -30 Volts with its internal pull-down resistors connected to VPP. Please notice that Texas Instruments designed the calculator to accommodate the NEC LD8118L VFD, too. We refer these models as TI-2550 III (Version 2).

Display Layout:

Itron FG95B1

The Output Decoder PLA of the TMS1043NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1043 Pin 17 16 15 14 13 12 11 10
TMS1043 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Itron FG95B1 display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1043NL TI-2550 III n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction at a rate of about 240 Hz with one Blank State after R0 and R8 shorter than R7 to R1:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 = 14 ICT = 0.28 ms
Active Digit Time R7 to R0 = 18 ICT = 0.36 ms
Trailing Digit Blanking = 2 ICT = 0.04 ms
Blank State R0 → R8 = 13 ICT = 0.26 ms
Display Cycle Time = 207 ICT = 4.14 ms

TMS1043BNL

Device-under-Test:

Package Markings Top: TMS1043NL, ZA0352, BSP 7710
Package Markings Bottom: DP1043BS, SINGAPORE
Donor Calculator: TI-2550 III, MTA 4077

Keyboard: The TI-2550 III makes use of a keyboard with snap-action dome switches arranged in an 7*4 matrix with the rows connected to the R0-R6 Outputs (Display Scan) and the columns connected to the K1-K8 Inputs (Keyboard Scan) of the TMS1043BNL single-chip calculator circuit.

Keyboard Matrix of the TI-2550 III:

  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)        

Display: The TI-2550 III makes use of a 9-digit NEC LD8118L low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1043BNL and biased to approximately -30 Volts with its internal pull-down resistors connected to VPP. Please notice that Texas Instruments designed the calculator to accommodate the Itron FG95B1 VFD, too. We refer these models as TI-2550 III (Version 1).

Display Layout:

NEC LD8118L

The Output Decoder PLA of the TMS1043BNL is programmed for 7-Segment displays with the following Output Assignments:

TMS1043B Pin 17 16 15 14 13 12 11 10
TMS1043B Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the NEC LD8118L display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1043BNL TI-2550 III n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction at a rate of about 240 Hz with one Blank State after R0 and R8 shorter than R7 to R1:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 = 14 ICT = 0.28 ms
Active Digit Time R7 to R0 = 18 ICT = 0.36 ms
Trailing Digit Blanking = 2 ICT = 0.04 ms
Blank State R0 → R8 = 13 ICT = 0.26 ms
Display Cycle Time = 207 ICT = 4.14 ms

TMS1044NL

Device-under-Test:

Package Markings Top: TMS1044NL, KSP 7723
Package Markings Bottom: ⚫JP1044S, SINGAPORE
Donor Calculator: Bohsei Model 1000, September 1977

Keyboard: The Bohsei Model 1000 makes use of a keyboard with triangular snap-action dome switches (United States Patent 3,796,843 from March 12, 1974) arranged in a 9*4 matrix with the rows connected to the R0-R8 Outputs (Display Scan) and the columns connected to the K2-K8 and the "virtual" K10 Inputs (Keyboard Scan) of the TMS1044NL single-chip calculator circuit.

Keyboard Matrix of the Bohsei Model 1000:

  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  

Notes: K10 is a "virtual" 5th Keyboard Input line connected with two diodes to the K2 and K8 Keyboard Inputs of the TMS1044NL

Display: The Bohsei Model 1000 makes use of an 8-digit Itron DP84K low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1044NL and biased to approximately -26 Volts with its internal and three external (R6-100k Ohm, R7-100k Ohm, R8-12k Ohm) pull-down resistors connected to VPP.

Display Layout:

Itron DP84K

The Output Decoder PLA of the TMS1044NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1044 Pin 17 16 15 14 13 12 11 10
TMS1044 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Itron DP84K display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1044NL Bohsei 1000 n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 240 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 16 ICT = 0.12 ms or 0.32 ms
Trailing Digit Blanking = 12 or 2 ICT = 0.24 ms or 0.04 ms
Additional State RX State (Decimal Point) = 27 ICT = 0.54 ms
Display Cycle Time = 207 ICT = 4.14 ms

TMS1044NL

Device-under-Test:

Package Markings Top: TMS1044NL, KSP 7723
Package Markings Bottom: *JP1044S, SINGAPORE
Donor Calculator: Bohsei Model 1000, September 1977
Explored Calculator: Privileg 858 MD, January 1977

Keyboard: The Privileg 858 MD makes use of a keyboard with with conductive rubber switches arranged in a 9*4 matrix with the rows connected to the R0-R8 Outputs (Display Scan) and the columns connected to the K2-K8 and the "virtual" K10 Inputs (Keyboard Scan) of the TMS1044NL single-chip calculator circuit.

Keyboard Matrix of the Privileg 858 MD:

  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  

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

Display: The Privileg 858 MD makes use of a 9-digit Futaba 9-ST-10 low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1044NL and biased to approximately -28 Volts with its internal pull-down resistors connected to VPP.

Display Layout:

Futaba 9-ST-10

The Output Decoder PLA of the TMS1044NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1044 Pin 17 16 15 14 13 12 11 10
TMS1044 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Futaba 9-ST-10 display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1044NL Privileg 858 MD n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 240 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 16 ICT = 0.12 ms or 0.32 ms
Trailing Digit Blanking = 12 or 2 ICT = 0.24 ms or 0.04 ms
Additional State RX State (Decimal Point) = 27 ICT = 0.54 ms
Display Cycle Time = 207 ICT = 4.14 ms

TMS1044NL

Device-under-Test:

Package Markings Top: TMS1044NL, MT 8018, SINGAPORE
Package Markings Bottom: NONE
Donor Calculator: Brinlock Model 806, June 1980

Keyboard: The Brinlock Model 806 makes use of a keyboard with triangular snap-action dome switches (United States Patent 3,796,843 from March 12, 1974) arranged in a 9*4 matrix with the rows connected to the R0-R8 Outputs (Display Scan) and the columns connected to the K2-K8 and the "virtual" K10 Inputs (Keyboard Scan) of the TMS1044NL single-chip calculator circuit.

Keyboard Matrix of the Brinlock Model 806:

  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  

Notes: K10 is a "virtual" 5th Keyboard Input line connected with two diodes to the K2 and K8 Keyboard Inputs of the TMS1044NL

Display: The Brinlock Model 806 makes use of a 9-digit Futaba 9-ST-11 low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1044NL and biased to approximately -28 Volts with its internal pull-down resistors connected to VPP.

Display Layout:

Futaba 9-ST-11

The Output Decoder PLA of the TMS1044NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1044 Pin 17 16 15 14 13 12 11 10
TMS1044 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Futaba 9-ST-11 display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1044NL Brinlock 806 n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 240 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 16 ICT = 0.12 ms or 0.32 ms
Trailing Digit Blanking = 12 or 2 ICT = 0.24 ms or 0.04 ms
Additional State RX State (Decimal Point) = 27 ICT = 0.54 ms
Display Cycle Time = 207 ICT = 4.14 ms

TMS1044NL

Device-under-Test:

Package Markings Top: TMS1044NL, TP 7745
Package Markings Bottom: JP1044T, SINGAPORE
Donor Calculator: Unisonic Model 1040-1, December 1977

Keyboard: The Unisonic Model 1040-1 makes use of a keyboard with conductive rubber switches arranged in a 9*4 matrix with the rows connected to the R0-R8 Outputs (Display Scan) and the columns connected to the K2-K8 and the "virtual" K10 Inputs (Keyboard Scan) of the TMS1044NL single-chip calculator circuit.

Keyboard Matrix of the Unisonic Model 1040-1:

  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

Notes: K10 is a "virtual" 5th Keyboard Input line connected with two diodes to the K2 and K8 Keyboard Inputs of the TMS1044NL

Display: The Unisonic Model 1040-1 makes use of a 9-digit Futaba 9-ST-08A low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1044NL and biased to approximately -27 Volts with its internal pull-down resistors connected to VPP.

Display Layout:

Futaba 9-ST-08A

The Output Decoder PLA of the TMS1044NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1044 Pin 17 16 15 14 13 12 11 10
TMS1044 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Futaba 9-ST-08A display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1044NL Unisonic 1040-1 n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 240 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 16 ICT = 0.12 ms or 0.32 ms
Trailing Digit Blanking = 12 or 2 ICT = 0.24 ms or 0.04 ms
Additional State RX State (Decimal Point) = 27 ICT = 0.54 ms
Display Cycle Time = 207 ICT = 4.14 ms

TMS1045NL

Device-under-Test:

Package Markings Top: TMS1045NL, KSΔ7723
Package Markings Bottom: NONE
Donor Calculator: Canon F-31, June 1977

Keyboard: The Canon F-31 makes use of a keyboard with conductive rubber switches arranged in a 9*4 matrix with the rows connected to the R0-R8 Outputs (Display Scan) and the columns connected to the K2-K8 and the "virtual" K10 Inputs (Keyboard Scan) of the TMS1045NL single-chip calculator circuit. The [+ - 2 - 0 - F] sliding switch is connected between the R1, R2, and R0 Outputs and K1 Input. R7 is jumpered with a Diode directly to K1.

Keyboard Matrix of the Canon F-31:

  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  

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 TMS1045NL

Display: The Canon F-31 makes use of a 9-digit Futaba 9-ST-11 low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1045NL and biased to approximately -30 Volts with its internal pull-down resistors connected to VPP.

Display Layout:

Futaba 9-ST-11

The Output Decoder PLA of the TMS1045NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1045 Pin 17 16 15 14 13 12 11 10
TMS1045 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Futaba 9-ST-11 display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1045NL Canon F-31 n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 240 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 16 ICT = 0.12 ms or 0.32 ms
Trailing Digit Blanking = 12 or 2 ICT = 0.24 ms or 0.04 ms
Additional State RX State (Decimal Point) = 27 ICT = 0.54 ms
Display Cycle Time = 207 ICT = 4.14 ms

TMS1045NL

Device-under-Test:

Package Markings Top: TMS1045NL⚫, KTΔ7809
Package Markings Bottom: NONE
Donor Calculator: Canon Canola L813, May 1978

Keyboard: The Canon Canola L813 makes use of a keyboard with conductive rubber switches arranged in a 9*4 matrix with the rows connected to the R0-R8 Outputs (Display Scan) and the columns connected to the K2-K8 and the "virtual" K10 Inputs (Keyboard Scan) of the TMS1045NL single-chip calculator circuit. The [+ - 4 - 2 - 0 - F] sliding switch is connected between the R1, R2, and R0 Outputs and K1 Input and the [ - AM] sliding switch is connected between R8 and K1. R7 is jumpered with a Diode directly to K1.

Keyboard Matrix of the Canon Canola L813:

  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

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 TMS1045NL

Display: The Canon Canola L813 makes use of a 9-digit Futaba 9-BT-18A low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1045NL and biased to approximately -32 Volts with its internal pull-down resistors connected to VPP.

Display Layout:

Futaba 9-BT-18A

The Output Decoder PLA of the TMS1045NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1045 Pin 17 16 15 14 13 12 11 10
TMS1045 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Futaba 9-BT-18A display in the pictured way. The additional Comma and Thousands Indicators are not connected. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1045NL Canon L813 n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 240 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 16 ICT = 0.12 ms or 0.32 ms
Trailing Digit Blanking = 12 or 2 ICT = 0.24 ms or 0.04 ms
Additional State RX State (Decimal Point) = 27 ICT = 0.54 ms
Display Cycle Time = 207 ICT = 4.14 ms

TMS1045NL

Device-under-Test:

Package Markings Top: TMS1045NL, ___TΔ8432
Package Markings Bottom: NONE
Donor Calculator: Canon Canola L813 II, August 1984

Keyboard: The Canon Canola L813 II makes use of a keyboard with conductive rubber switches arranged in a 9*4 matrix with the rows connected to the R0-R8 Outputs (Display Scan) and the columns connected to the K2-K8 and the "virtual" K10 Inputs (Keyboard Scan) of the TMS1045NL single-chip calculator circuit. The [+ - 4 - 2 - 0 - F] sliding switch is connected between the R1, R2, and R0 Outputs and K1 Input and the [ - AM] sliding switch is connected between R8 and K1. R7 is jumpered with a Diode directly to K1.

Keyboard Matrix of the Canon Canola L813 II:

  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

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 TMS1045NL

Display: The Canon Canola L813 II makes use of a 9-digit Futaba 9-BT-18A low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1045NL and biased to approximately -31 Volts with its internal pull-down resistors connected to VPP.

Display Layout:

Futaba 9-BT-18A

The Output Decoder PLA of the TMS1045NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1045 Pin 17 16 15 14 13 12 11 10
TMS1045 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Futaba 9-BT-18A display in the pictured way. The additional Comma and Thousands Indicators are not connected. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1045NL Canon L813 II n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 240 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 16 ICT = 0.12 ms or 0.32 ms
Trailing Digit Blanking = 12 or 2 ICT = 0.24 ms or 0.04 ms
Additional State RX State (Decimal Point) = 27 ICT = 0.54 ms
Display Cycle Time = 207 ICT = 4.14 ms
TMS1045NL

Device-under-Test:

Package Markings Top: TMS1045NL, MT 8001, SINGAPORE
Package Markings Bottom: NONE
Donor Calculator: Toshiba BC-8111B, January 1980

Keyboard: The Toshiba BC-8111B makes use of a keyboard with conductive rubber switches arranged in a 9*4 matrix with the rows connected to the R0-R8 Outputs (Display Scan) and the columns connected to the K2-K8 and the "virtual" K10 Inputs (Keyboard Scan) of the TMS1045NL single-chip calculator circuit.

Keyboard Matrix of the Toshiba BC-8111B and its siblings BC-8018B and BC-8112SL:

  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: The Toshiba BC-8111B makes use of a 9-digit Futaba 9-ST-08A low-voltage Vacuum Fluorescent Display (VFD) connected directly to the respective 9 R Outputs (Display Scan) and 8 O Outputs (Segments) of the TMS1045NL and biased to approximately -27 Volts with its internal pull-down resistors connected to VPP.

Display Layout:

Futaba 9-ST-08A

The Output Decoder PLA of the TMS1045NL is programmed for 7-Segment displays with the following Output Assignments:

TMS1045 Pin 17 16 15 14 13 12 11 10
TMS1045 Port O0 O1 O2 O3 O4 O5 O6 O7
Segment A B C D E F G DP
The Segment drivers A-G and DP (Decimal Point) are connected to the Futaba 9-ST-08A display in the pictured way. 

Display Fonts:

Type Calculator Number Fonts Decimal
Separator
Thousands
Separator
Entry
Overflow
Calculating
Overflow
Minus Memory
Indicator
TMS1045NL Toshiba BC-8111B n.a.    

Scanning: Display and keyboard scanning is performed in R8 → R0 direction followed by an RX State to display the Decimal Point at the desired position at a rate of about 240 Hz. Blank Positions have a shorter Active Digit Time and longer Trailing Digit Blanking Time:

Instruction Cycle Time (ICT) = 6 Clocks = 0.02 ms @ CK=300 kHz
Leading Digit Blanking Time = 2 ICT = 0.04 ms
Active Digit Time R8 to R0 = 6 or 16 ICT = 0.12 ms or 0.32 ms
Trailing Digit Blanking = 12 or 2 ICT = 0.24 ms or 0.04 ms
Additional State RX State (Decimal Point) = 27 ICT = 0.54 ms
Display Cycle Time = 207 ICT = 4.14 ms

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

Joerg Woerner, January 7, 2023. No reprints without written permission.