DATAMATH CALCULATOR MUSEUM
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DATAMATH CALCULATOR MUSEUM |
Unisonic LC-7311BK
| Date of introduction: | 1981 | Display technology: | LCD |
| New price: | Display size: | 8 | |
| Size: | 3.9" x 2.4" x 0.25" 100 x 60 x 6 mm3 |
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| Weight: | 1.6 ounces, 44 grams | Serial No: | 5374901 |
| Batteries: | 2*LR54 | Date of manufacture: | year 1981 |
| AC-Adapter: | Origin of manufacture: | Taiwan | |
| Precision: | 8 | Integrated circuits: | Sharp LI3033MT |
| Memories: | 1 | ||
| Program steps: | Courtesy of: | Joerg Woerner |
Does this
Unisonic LC-7311BK calculator look familiar to you?
Dismantling
the featured LC-7311BK manufactured in 1981 by an unknown
OEM (Original Equipment Manufacturer) in Taiwan reveals a clean design
centered around a Sharp LI3033MT single-chip calculator circuit soldered on a
double-sided printed circuit board (PCB) and powered by two small LR54 (LR1130) batteries.
Inspecting the PCB of this Unisonic LC-7311BK calculator brought our attention to a small mark reading MK65-6,
we spotted this PCB-Mark already with near identical offspring like the
IMA LC
688, NSC Novus Electronics NS220, TI-1755
and
TI-1756 and suspect to locate it in the Technico MK 65, too. Plus the Asaflex MK 653, Benkson CAL-20, Levi MK 1652, MBO MK65, M-Office MK650, Olympia MK 65, Privileg Senator,
Radio Shack EC-376, Satek MK 652 and Unisonic LC-7311M. Based on the PCB-Marks located with the
TI-2130 and its twin Technico
F-800 we are almost positive that
the LC-7311BK and its siblings were manufactured by
Inventa Electronics Corporation
of Taipei, Taiwan. We started compiling a list
of the PCB-Marks on calculators
manufactured by OEMs for Texas Instruments.
If you have additions to the above article please email: joerg@datamath.org.
© Joerg Woerner, March 15, 2020. No reprints without written permission.