NSC Novus Electronics NS101A Data Checker (1st Design)

Date of introduction:  December 1981 Display technology:  LCD
New price:  $16.99 (SRP May 1982) Display size:  8
Size:  2.8" x 6.0" x 0.30"
 71 x 153 x 8 mm3
Weight:  2.8 ounces, 79 grams Serial No:  
Batteries:  2*LR44  Date of manufacture:  mth 12 year 1981
AC-Adapter:   Origin of manufacture:  Taiwan
Precision:  8  Integrated circuits:  NEC uPD1831G
Memories:  1    
Program steps:   Courtesy of:  Joerg Woerner
    Download manual:   (US, FR: 3.0 MByte)

National Semiconductor entered the market of Checkbook Calculators with the NS103 Data Checker in May 1978. 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 seven different family members:

1978: National Semiconductor NS103, 3 Memories
1979: National Semiconductor NS107, 2+1 Memories, Credit card size
1980: National Semiconductor NS103A, 3 Memories
1981: NSC Novus Electronics NS103A, 3 Memories
1981: This NSC Novus Electronics NS101A, 1 Memory
1982: NSC Novus Electronics NS101A, 1 Memory, Gold
1982: NSC Novus Electronics NS100A, 1 Memory, Credit card size

Dismantling the featured NSC Novus Electronics NS101A Data Checker sporting just one memory and manufactured in December 1981 in Taiwan reveals a clean design centered around a NEC uPD1831G single-chip calculator circuit soldered on a single-sided printed circuit board (PCB) and powered by two small LR44 batteries.

Please notice the changes of the Brand Identity of the Data Checker product line over time.

Inspecting the PCB of this NS101A manufactured in December 1981 brought our attention to a small mark reading 103C, most likely a reference to Type 103, and Revision C of the design (schematics and layout).

Please find an overview of the PCB-Marks we discovered so far on Account Manager calculators.

Comparing this NS101A sporting a 103C mark and a NS101A with a 103C-2 mark manufactured a few month later, reveals some interesting differences in the PCB technology:

PCB Mark


Calculator Chip

Lot  Code

PCB Technology

103 C NEC uPD1831G P14225 single-sided, wire jumpers in 2 different length
103 C-2 NEC uPD1831G P17435 single-sided, conductive print over PCB traces

The Royal LCB 830 and LCB 835 twins went through the same changes in PCB technology.

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, March 2, 2020. No reprints without written permission.