DATAMATH

DATAMATH CALCULATOR MUSEUM

Montgomery Ward P8M alias TXI-8646A

Date of introduction:	August 20, 1973	Display technology:	LED-modules + lens
New price:	$99.50	Display size:	8
Size:	5.5" x 3.0" x 1.4"
Weight:	5.5 ounces	Serial No:	47F-0025055
Batteries:	4*AA NiCd	Date of manufacture:
AC-Adapter:		Origin of manufacture:	USA
Precision:		Integrated circuits:	WD LC1552B
Memories:	1
Program steps:		Courtesy of:	David Smith

This boxy calculator does not look like a Texas Instruments product. To identify it you have to know something about the coding used by Montgomery Ward:

Models starting with

	TXI were produced by Texas Instruments
	DAN were produced by APF
	DNS were produced by National Semiconductors (later Novus)
	GLE by Lloyd's

If you remember the famous Texas Instruments Datamath (TI-2500) and add a 4-key memory you would get a similar calculator to this wonderful find. There are only few calculators reported which have no direct counterpart of existing TI-products. With the P8F alias TXI-8644A and the P8P alias TXI-8645A two similar calculator without memory were sold, too.

If you dismantle this calculator, one question will arise immediately:
Was this calculator really manufactured by Texas Instruments ?

The integrated circuit inside is not manufactured by Texas Instruments and one step ahead the TI chips of that era. The TI-2550 with similar complexity (%-key and 4-key memory) was introduced later. Maybe TI had a delay in the development of the TMS0601, the direct counterpart of the Western Digital LC1552 used in the P8M.

The keyboard of the calculator is a mixture of the TI-1500 keys and the grid of the Datamath. The display board was manufactured by Texas Instruments, too. And we could proof easily: This cutie IS a Texas Instruments calculator. The answer is found in the magic number 13-04-709-478 on the printed circuit board. Read more here. With the Radio Shack EC-300 Texas Instruments used the LC1552 a second time.

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

Datamath™ is a trademark of Texas Instruments.

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