Unisonic XL-1105 (Version 1)

Date of introduction:  May 1984 Display technology:  LCD
New price:   Display size:  8
Size:  4.7" x 4.1" x 1.0"
 120 x 106 x 25 mm3
Weight:  3.0 ounces, 86 grams Serial No:  
Batteries:  n.a.  Date of manufacture:  year 1984
AC-Adapter:   Origin of manufacture:  Taiwan
Precision:  8  Integrated circuits:  Sharp
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner

Does this Unisonic XL-1105 calculator sold in 1984 look familiar to you? It seems to be identical with the Unisonic XL-1110. And many more siblings...

Dismantling the featured XL-1105 manufactured in 1984 by Cal-Comp Electronics, an OEM (Original Equipment Manufacturer) in Taiwan, reveals a clean design centered around an unknown Sharp single-chip calculator circuit soldered on a double-sided printed circuit board (PCB) and powered by solar cells.

Inspecting the PCB of this XL-1105 calculator brought our attention to a small mark reading SD9-11, most likely a reference to Type Small Desktop 9 and Revision 1.1 of the design (schematics and layout). We spotted this PCB-Mark already with the XL-1110 and its near identical offsprings TI-1795 / Radio Shack EC-2006A with revisions SD9-13, SD9-14, and SD-9-15. We started compiling a list of the PCB-Marks on calculators manufactured by OEMs for Texas Instruments.

The XL-1105 was soon replaced with a 2nd Version sporting smaller solar cells.

If you have additions to the above article please email:

Joerg Woerner, April 13, 2020. No reprints without written permission.