DATAMATH CALCULATOR MUSEUM

X-RAY See-through calculators

Ever thought about the unvisible parts of your electronic calculator ? Edward Soudentas took some vintage calculators onto the X-ray machine and gives us unbelievable views of early technology. The Datamath Calculator Museum provides you 4 different calculators manufactured and sold by Texas Instruments and gives you additional views of the whole calculator and the printed circuit board.

All the X-ray pictures could be found unaltered on Edwards wonderful website www.petergof.com. Please follow the x-ray link.

Texas Instruments SR-11

The SR-11 was introduced September, 1973 as the successor of the SR-10 scientific calculator. It uses 3 AA-sized NiCd-batteries and a 12-digit LED display. You'll easily locate the 28-pin TMS0602 calculator IC surrounded by 4 display drivers. The 3 batteries are located under the LED display. This picture without the batteries shows the small display board and all the tiny components necessary in an early TI calculator. Note: This is a rear view.

Texas Instruments TI-1250


The TI-1250 was introduced June, 1975 as the first one-chip calculator. Together with it's sibblings millions of this design were sold.	You'll easily locate the 28-pin TMS0952 calculator IC. This picture gives you an idea of the keyboard with the small metal-domes pressed against wires.	Not too much components on the printed circuit board! The 9-digit LED-stick is located on top, the metal-domes of the keyboard are hidden under the black foil.

Texas Instruments TI-30


The TI-30 was introduced June, 1976 as the first scientific one-chip calculator. It was probably the best selling calculator ever.	You'll easily locate the 28-pin TMC0981 calculator IC. This picture gives you a perfect view of the x/y-matrix keyboard with the small metal-domes (x-line) pressed against wires (y-line).	The TI-1250 uses a small printed circuit board to accommodate the display, the TI-30 integrated even the calculator chip on the display board!

Texas Instruments TI-1750


With the TI-1750 Texas Instruments entered April, 1977 the market of LCD-calculators. Note: Design and manufacturing was done in Japan.	The 44-pin Quad-Flatpack calculator IC manufactured by Toshiba is located under the EPSON manufactured yellow-LC display. The calculator runs more than 3000 hours from 2 little coin batteries.	Two interesting items on this printed circuit board: It is one sided with thick "bridges" to give a second layer of connections. The keyboards consists of small conductive pieces pressed against the metal-fingers on the board.

Texas Instruments TI-1795+


The TI-1795+ traced back to the original TI-1795 introduced already in 1984 and the basic design was available as TI-1795SV till 2002.	This late TI-1795+ was manufactured in 1996 and makes still use of a conventional housed integrated circuit for the calculator brain. Please notice the empty battery compartment on the left side of the housing.

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


The SR-11 was introduced September, 1973 as the successor of the SR-10 scientific calculator. It uses 3 AA-sized NiCd-batteries and a 12-digit LED display.	You'll easily locate the 28-pin TMS0602 calculator IC surrounded by 4 display drivers. The 3 batteries are located under the LED display.	This picture without the batteries shows the small display board and all the tiny components necessary in an early TI calculator. Note: This is a rear view.