DATAMATH CALCULATOR MUSEUM
Western Auto Citation aka M4988 (Version 1)
|Date of introduction:||May 1976||Display technology:||LED-stick|
|New price:||Display size:||8|
|Size:|| 5.5" x 2.8" x 1.4"
138 x 70 x 35 mm3
|Weight:||3.9 ounces, 110 grams||Serial No:||0007284|
|Batteries:||9V||Date of manufacture:||wk 41 year 1976|
|AC-Adapter:||AC9180||Origin of manufacture:||USA|
|Program steps:||Courtesy of:||Peter Muckermann|
Auto extended in May 1976 its portfolio of portable electronic calculators with
the M4988 aka "Citation" based on Texas Instruments'
TI-1270 to complement the
M4986 and M4987. Main differences between the M4988 and the TI-1270 are the
color of the keyplate and the missing TI logo.
Dismantling the featured M4988 with Date code 4176 LTA and manufactured in October 1976 in Lubbock, Texas reveals a very efficient and cost-optimized design with a single-sided printed circuit board (PCB) centered around a TMS0974 single-chip calculator circuit based on the TMS1000, the World's first Microcomputer.
The final step of cost reduction of the of the M4988 was introduced just a few months before its discontinuation and included a smaller encapsulation of the TMS0974 Chip. While the original design was using a 0.6” wide 28-pin DIP (Plastic Dual In-line Package with a 0.1” / 2.54 mm lead pitch) encapsulation, switched the final design to a 0.4” wide 28-pin SPDIP (Shrink Plastic Dual In-line Package with a 0.07” / 1.778 mm lead pitch) encapsulation.
Learn more about the evolution of the TI-1270 between April 1976 and its discontinuation in 1977.
Learn more about the different
Product Labels used with the TI-1250
- here at the Datamath Calculator Museum we classify the featured M4988 as
Hardware Version 1, PCB Type 2 and Product Label Style 3, Beige, Western Auto.
If you have additions to the above article please email: firstname.lastname@example.org.
© Joerg Woerner, December 5, 2001. No reprints without written permission.