Western Auto electronic Wizard aka M4993

Date of introduction:  1974 Display technology:  LED-stick w/o lens
New price:  $34.95 Display size:  8
Size:  5.1" x 2.9" x 1.3"
 130 x 74 x 34 mm3
Weight:  5.1 ounces, 144 grams Serial No:  09300
Batteries:  3*AA  Date of manufacture:  wk 36 year 1974
AC-Adapter:  AC9160 Origin of manufacture:  USA
Precision:  8 Integrated circuits:  TMS0803
Program steps:   Courtesy of:  Joerg Woerner

M4993_Back.jpg (52275 Byte)Western Auto Supply Company began in 1973 distributing portable electronic calculators manufactured by Texas Instruments under their own branding with a prominent "electronic Wizard" logo. The M4995 "electronic Wizard" is a close relative of the Montgomery Ward P8P a.k.a. TXI-8645A with the unusual [-=] and [+=] keys but misses the sliding switch to select between floating [F] or [2] or [4] decimal places for the answer. Texas Instruments ceased manufacturing of the Montgomery Ward P8F, P8M, P8P and the related Western Auto M4995 in Summer 1974 and both companies introduced calculators based on the Exactra 23 named P100 and M4993, respectively.

M4993_1.jpg (21271 Byte)M4993_LAB.jpg (7398 Byte)The only differences to the Exactra 23 are the display frame, and the faceplate for the keys. 

M4993_PCB.jpg (82532 Byte)M4993_DISP.jpg (36640 Byte)Dismantling featured M4993 with Date code 364 and manufactured in September 1974 in Texas reveals a printed circuit board (PCB) 100% identical with the Exactra 23 but to our surprise the display construction looks very unfamiliar to us. We couldn't identify the manufacturer of this board.

The manual provided with this calculators states: TXI 4993A47
, distributed by Western Auto Supply Co.

Instruments introduced the TI-1200 in March 1975 and followed within just a few months with the TI-1250 featuring a 4-key Memory and a [CS] or [+/-] key. Western Auto consequently dropped the Exactra 23 based M4993 and introduced the M4986 and M4987 "electronic Wizard" calculators accordingly.




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Joerg Woerner, March 5, 2006. No reprints without written permission.