DATAMATH PICTURES

This SR-51E (Engineering Sample) was manufactured in August 1974
by Texas Instruments in Dallas, TX.

The battery compartment of the SR-51E gives access to the electrical
contacts used to connect the PC-100 printer cradle.

The Main printed circuit board (PCB) of the SR-51E calculator. The brain of the
calculator uses the TMC0501 and a stack of 2 SCOM (TMC0522,523) circuits.
A second PCB holds the keys, display and driver circuits.

The Main-PCB of the of the SR-51E calculator with the paper labels removed.

The Display and Keyboard PCB of the SR-51E with two Texas Instruments
SN27882 display drivers and fourteen 7-segment LED-Displays.

Close-up view of the TMC0501 Arithmetic Chip.

Close-up view of the TMC0522/TMC0523 Scanning and Read-Only Memory Chips.

Close-up view of the SN74LS74 Chip from the Clock Generator.

Close-up view of the SN74LS02 Chip from the Clock Generator.

Close-up view of one of the two SN27882 Display Driver Chips.

Close-up of the 14-digit LED Display with magnifying lens.