Montgomery Ward P300 aka TXI-8663A (Version 1) 

Date of introduction:  June 1974 Display technology:  LED modules + lens
New price:   Display size:  8 + 2
Size:  6.1" x 3.1" x 1.5"
 156 x 78 x 38 mm3
Weight:  9.2 ounces, 262 grams Serial No:  47X-011706
Batteries:  3*AA NiCd Date of manufacture:  wk 30 year 1974
AC-Adapter:  AC9130 Origin of manufacture:  USA
Precision:  8 Integrated circuits:  TMS0120, 2*SN75493, 2*SN27423
Memories:   Displays:  DIS115E (12*DIS279)
Program steps:   Courtesy of:  Joerg Woerner

This Montgomery Ward P300 aka TXI-8663A could easily identified as larger brother of the P200 aka TXI-8662A and a close relative of the SR-10

Both calculators use the same electronics, the same layout of the keyboard and even an identical mold for the housing bottom. The different look is achieved through a new mold for the upper half of the housing and a different color of the function keys. The color of the housing is slightly different, too.

Texas Instruments changed in or around August 1974 the LED display of the P300 and replaced the DIS115E module known from the SR-10 Version 2 with a DIS175 module based on Bowmar's Optostic technology.

Compare it with it's sibling P200 and another SR-10 clone, the Radio Shack EC-425. If you are looking for an SR-10 with blue function keys, don't miss this SR-10 Rebuilt.

Don't miss the rare TXI-8661A based on the Exactra 23 calculator.

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If you have additions to the above article please email:

Joerg Woerner, December 5, 2001. No reprints without written permission.