National Semiconductor NS103A Data Checker

Date of introduction:  1980 Display technology:  LCD
New price:  $29.95 (SRP April 1980) 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 11 year 1981
AC-Adapter:   Origin of manufacture:  Taiwan
Precision:  8  Integrated circuits:  NEC uPD1833G
Memories:  3    
Program steps:   Courtesy of:  Ken H. Meine
    Download manual:   (US: 2.0 MByte)

National Semiconductor introduced already in 1978 with the NS103 Data Checker an electronic record keeper with three continuous memories to track bank and charge account balances with dedicated keys:

Memory 1 [CHK] [DEP] [BAL] [A]
Memory 2 [PMT] [CHG] [BAL] [B]
Memory 3 [PMT] [CHG] [BAL] [C]
Total sum of Memories [GT]

The successor of the NS103, known as NS103A, simplified the use of the memories by removing the redundant [A], [B], and [C] keys and replaced the inconvenient three-way power-switch with two dedicated [ON] and [OFF] keys and a [DS] key to toggle between two entry modes:

Indicator (--) Floating decimal with manual insertion of the decimal using the [.] key
Indicator (AM) Add mode with the decimal automatically put in the dollars and cents position (0.00)

Dismantling the featured NS103A Data Checker manufactured in November 1981 in Taiwan reveals a clean design centered around a NEC uPD1833G single-chip calculator circuit, that was used with many other Account Manager calculators like the Canon Checkbook, IMA 130CBW, Radio Shack EC-306, Royal LCB 841, Texas Instruments TI-2200 Checkwriter, and Unisonic LC 263CK.

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

Inspecting the PCB of this NS103A manufactured in November 1981 brought our attention to a small mark reading NS_103B 1, most likely a reference to Type 103, and Revision B 1 of the design (schematics and layout).

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.

From a technical point of view this NS103A Data Checker could be called a basic calculator with three permanent (till the batteries die) memories, the left column of the memory keys would be [M-], the center column [M+], and the right column [MR]. Hoffmann-La Roche made use of this feature introducing the FITNESS 3 MICRO COMPUTER based on a stripped-down NS103A.

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: This National Semiconductor NS103A, 3 Memories
1981: NSC Novus Electronics NS103A, 3 Memories
1981: NSC Novus Electronics NS101A, 1 Memory
1982: NSC Novus Electronics NS101A, 1 Memory, Gold
1982: NSC Novus Electronics NS100A, 1 Memory, Credit card size

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, May 22, 2002. No reprints without written permission.