Royal CBC 80NT Checkbook Calculator

Date of introduction:  November 1986 Display technology:  LCD
New price:  $14.95 (SRP November 1986) Display size:  8
Size:  2.8" x 6.1" x 0.25"
 70 x 154 x 7 mm3
Weight:  2.5 ounces, 72 grams Serial No:  
Batteries:  LR54 Date of manufacture:  year 1987
AC-Adapter:   Origin of manufacture:  Taiwan
Precision:  8  Integrated circuits:  Toshiba T7752S
Memories:  3    
Program steps:   Courtesy of:  Ken H. Meine
    Download manual:   (US: 2.1 MByte)

Royal Typewriters and its sister company Triumph-Adler, part of Litton Industries, were sold in 1986 to Olivetti and is since September 2004 a private American company again and is today known as Royal Consumer Information Products Inc.

Royal entered the market of Checkbook Calculators with the LCB 841 in August 1980. 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 eleven different family members:

1980: Royal LCB 841, 3 Memories
1983: Royal LCB 830, 1 Memory, Wallet
1983: Royal LCB 835, 1 Memory, Purse
1986: This Royal CBC 80NT, Solar cells, Taiwan, 3 Memories
1987: Royal CBC 70, Taiwan, 1 Memory
1988: Royal CBC 80, Solar cells, Thailand, 3 Memories, US market
1988: Royal/Olivetti CBC 80, Solar cells, Thailand, 3 Memories, Canadian market
1988: Olivetti DII, Solar cells, Thailand, 3 Memories, European market
1989: Royal CBC 70, Thailand, 1 Memory
1993: Royal CBC 95, Solar cells, Thailand, 3 Memories
1998: Royal CBC 2000, Solar cells, China, 3 Memories

Dismantling the featured CBC 80NT Checkbook Calculator manufactured in 1987 in Taiwan reveals a clean design centered around a Toshiba T7752S single-chip calculator circuit soldered on a double-sided printed circuit board (PCB) and powered by four solar cells and a small LR54 (LR1130) backup battery.

Inspecting the PCB of this CBC 80NT manufactured in 1987 brought our attention to a small mark reading 308-16, most likely a reference to Type 308 and Revision 1.6 of the design (schematics and layout). We noticed the PCB-Mark 308 during our research on the PCBs of a lot of more or less identical Account Managers, find an overview of the OEM brands/models here.

Please find an overview of the PCB-Marks we discovered so far on 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, February 13, 2020. No reprints without written permission.