Unisonic LC 262CK

Date of introduction:  1981 Display technology:  LCD
New price:  $19.95 (SRP August 1982) Display size:  8
Size:  2.2" x 3.6" x 0.30"
 55 x 91 x 7 mm3
Weight:  1.4 ounces, 39 grams Serial No:  
Batteries:  2*LR43 Date of manufacture:  year 1983
AC-Adapter:   Origin of manufacture:  Taiwan
Precision:  8  Integrated circuits:  NEC uPD1833G
Memories:  3    
Program steps:   Courtesy of:  Ken H. Meine
    Download manual:   (US: 1.6M Bytes)

Unisonic entered the market of Checkbook Calculators with the LC 262 in 1979. It features Account Manager functionality with three permanent (till you remove the batteries) Memories and started a very successful product line. We discovered as of now ten different family members:

1979: LC 262, 3 Memories, Credit Card size
1981: This LC 262CK, 3 Memories, Credit Card size
1981: LC 263CK, 3 Memories
1981: LC 224CK, 1 Memory
1982: LC 224CKE, 1 Memory, Pen
1983: LC 224CKM, 1 Memory, Pen
1983: LC 223CK, 1 Memory, Credit Card size
1985: LC 225CK, 1 Memory
1988: LC 226CK, 1 Memory, Taiwan
1990: LC 226CK, 1 Memory, Thailand

Dismantling the featured LC 262CK manufactured in 1983 in Taiwan reveals a clean design centered around a NEC uPD1833G single-chip calculator circuit soldered on a double-sided printed circuit board (PCB) and powered by two small LR43 batteries.

Inspecting the PCB of this Unisonic LC 262CK calculator brought our attention to a small mark reading 107, most likely a reference to the National Semiconductor NS107 calculator introduced already in 1979. We discovered on the PCB of the Radio Shack EC-306 Electronic Checkbook calculator a similar number and compiled a list of the PCB-Marks we discovered on similar Account Manager calculators.

Learn more about single-chip calculator circuits used in Account Manager Calculators.

Don't miss the Corvus CheckMaster introduced by Mostek already in 1975. This rare product retains the balance of your memory even when shut off but uses power-hungry electronics.

If you have additions to the above article please email:

Joerg Woerner, January 4, 2020. No reprints without written permission.