DATAMATH CALCULATOR MUSEUM |
Western Auto Citation aka 66-4986-7 (Version 2)
Date of introduction: | 1977 | Display technology: | LED-stick |
New price: | Display size: | 8 | |
Size: | 5.4" x 2.8" x
1.3" 138 x 72 x 32 mm3 |
||
Weight: | 3.0 ounces, 84 grams | Serial No: | |
Batteries: | 9V | Date of manufacture: | wk 29 year 1978 |
AC-Adapter: | AC9180 | Origin of manufacture: | USA (LTA) |
Precision: | Integrated circuits: | TMC1992 | |
Memories: | |||
Program steps: | Courtesy of: | Joerg Woerner |
With the discontinuation of the TI-1200 family in 1977, Western Auto consequently replaced the M4986 "Citation" calculators and its siblings M4987 and M4988 with products based on the TI-1000 family. While the backside of the revised "Citation" calculator is missing any reference to the previous M4986 designation, sports the sales box a part number 66-4986-7, obviously a reference to the original naming scheme. Please find in the table below a cross reference between Western Auto's 1976/1977 and 1977/1878 calculator offerings:
Western Auto 1976/1977 |
Texas Instruments 1976/1977 |
Western Auto 1977/1978 |
Texas Instruments 1977/1978 |
Citation M4986 |
TI-1200 | Citation 66-4986-7 |
TI-1000 |
Citation M4987 |
TI-1250 | Citation 66-4987-5 |
TI-1025 |
Citation M4988 |
TI-1270 | Citation 66-4988-3 |
TI-1050 |
The
eye-catching "woody" design of the TI-1200 based M4986 "Citation" calculator was
dropped with its successor in favor of an elegant gray-white keyplate almost
matching the original TI-1000 look and feel. Other than that are the "Citation"
and TI-1000 identical, the back side of the calculators
tells you even its manufacturer Texas Instruments.
Dismantling the featured
66-4985-7 with Date code 2978 LTA and manufactured in
July 1978
in Lubbock, Texas reveals a very efficient and cost-optimized design
with a flexible single-sided printed circuit board (Flex-PCB) centered
around a TMC1992 single-chip calculator
circuit and powered by a 9V battery.
The TMC1990 calculator
chips are based on the TMS0970 used with
the TI-1200 family but integrate a power latch and power transistor to replace
the original sliding power switch with two more cost effective [ON] and [OFF]
keys.
Western Auto Supply Company ceased end of 1978
distributing "Citation" calculators manufactured by Texas Instruments, just 5
years after their journey began with the M4995
"electronic Wizard".
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, January 4, 2002. No reprints without written permission.