smd08722.jpg (45745 bytes)

Manufacturer: NATIONAL SEMICONDUCTOR
Model: 823
AKA: Novus 823
Year: 1974
Display: LED (8+1)
Circuits: NATIONAL SEMICONDUCTOR:
MM5738N, DM8864N
Dimensions: 134x76x35 mm
Power type: N-size batteries
Origin: USA
S/N:  
Owner: DEVIDTS Serge
Info: Strange power suplly

 

Feature  

Description 

Case:  

 

Color case:  

Black

Color keyboard:  

Black

Weight:  

 

Voltage selection:  

 

Adapter:  

DYNAMIC INSTRUMENT CORP:
Input: 110 V, 60 Hz, 5W
Output: 7.26 V DC, 100 mA

Power consumption:  

 

Working condition:  

 

Printed Circuit Boards (PCB's):  

 

Memories:  

 

Memories indication:  

 

Prog. steps:  

 

Decimal point handling:  

 

Rounding:  

 

Calculation overflow indication:  

 

Input overflow indication:  

 

Divide by Zero indication:  

 

Square root of negative value indication:  

 

Negative value indication:  

 

Constant function:  

 

Auto Power-off:  

 

Display details:  

 

Keyboard details:  

 

Printer:  

None

Extra features/remarks:  

 

Initial price:  

 

Overall quality rate (1-10):  

7

OEM-copies:  

 

Other sources of info:  

 

Advertisements/Publications:  

 

 

Example

Operation

Result

Use of the [K]-switch:
 

123 [X] 5 [%] [=]
125 [K=]

6.15
9.75

 

smd12978.jpg (33729 bytes)

Internals ^

smd11537.jpg (43228 bytes)

smd12977.jpg (14499 bytes)

Battery placement and mode-switch^
The switch is to disconnect the charger to the batteries,
so they will not heat the batteries to damage the internals of calculator.
Batteries are industrial type.