DATAMATH

DATAMATH CALCULATOR MUSEUM

Datamath Calculator Museum DCM-50A TMS1270 Adapter

Date of introduction:	September 21, 2022	Display technology:	n.a.
New price:		Display size:	n.a.
Size:	3.2" x 1.9" x 1.15" 81 x 48 x 32 mm³
Weight:	1.9 ounces, 54 grams	Serial No:	0001
Batteries:	n.a.	Date of manufacture:	mth 12 year 2022
AC-Adapter:	n.a.	Origin of manufacture:	USA
Precision:		Integrated circuits:	ZIF-Socket for TMS1040
Memories:
Program steps:		Courtesy of:	Joerg Woerner

The TMS1270 Product Family is based on the TMS1070 "computer-on-a-chip" introduced in 1974 with the original TMS1000 and its sibling TMS1200. The TMS1270 increased the number of Segment (O) Outputs compared to the TMS1200 and uses the modified Digit and Segment drivers of the TMS1070 for compatibility with low-voltage Vacuum Fluorescent Displays (VFDs) to allow for 12-digit desktop calculators like the TI-5200. The later TMS1300/TMS1370 not only doubled the internal Instruction Memories and Data Memories of its counterparts TMS1200 and TMS1270, respectively, but further increased the number of Digit (R) Outputs:

Device	TMS1000	TMS1070	TMS1100	TMS1170	TMS1200	TMS1270	TMS1300	TMS1370
Pin Count	28 pin	28 pin	28 pin	28 pin	40 pin	40 pin	40 pin	40 pin
Instruction ROM	1024*8	1024*8	2048*8	2048*8	1024*8	1024*8	2048*8	2048*8
Data RAM	64*4	64*4	128*4	128*4	64*4	64*4	128*4	128*4
R Outputs	11	11	11	11	13	13	16	16
O Outputs	8	8	8	8	8	10	8	8
Output Drivers	Standard	VFD	Standard	VFD	Standard	VFD	Standard	VFD

While the TMS1000 and TMS1070 chips are packaged either in 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), are the TMS1200 and TMS1270 chips using a 0.6” wide 40-pin DIP (Plastic Dual In-line Package with a 0.1” / 2.54 mm lead pitch) or or a 0.6” wide 40-pin SPDIP (Shrink Plastic Dual In-line Package with a 0.07” / 1.778 mm lead pitch) to accommodate the additional Output pins.

Unfortunately are the various chips utilizing the 40-pin Package exhibiting different pin-outs for their Outputs and Clock Oscillator connections.

The Datamath Calculator Museum DCM-50A Platform offers a lot of flexibility to access the features of calculators based on Texas Instruments’ single-chip calculator circuits but is centered around an 11x4 keyboard matrix, 11 Digit Drivers, 9 Segment Drivers and 28-pin Packages.

To access all features of a calculator based on the TMS1200 / TMS1270 / TMS 1300 / TMS1370 Product Families, the schematics and layout of the TMS1270 Adapter are providing accordingly:

• 40-pin Textool Test Socket
• Patch Field for all 40 Pins to allow for different pin-outs
• D11 Selection Switch to route R10, R11, R12, R13, or R14 to he left most LED Digit D11
• SP Selection Switch to route O7, O8, or O9 to the LED Decimal Point SP

Please notice that the TMS1270 Adapter needs to be plugged into the rightmost TMS1000 Pin-Headers on the DCM-50A Platform.

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