Manufacturer: BUSICOM
Model: 80DA
AKA: exec 80-DA
Year: 1971
Display: Tubes (8+1)
Circuits: TEXAS INSTRUMENTS: TMS0105
Dimensions: 200x145x54 mm
Power type: 110/220V
Origin:  
S/N:  
Owner: Many thanks to:
JANSSENS André from Belgium for the info.

 

Case: 
Color case: 
Color keyboard: 
Weight: 
Voltage selection: 
Power consumption: 
Working conditions: 
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: 
Auto constant function by pressing twice: 
Auto Power-off: 
Display details: 
Keyboard details: 
Printer: 
Printer roll: 
Printer inkt-ribbon: 
Extra features/remarks: 



 
 

Initial price: 
Overall quality rate (1-10): 
OEM-copies: 
Other sources of info: 
Advertisements/Publications: 


Beige.
Black.
1000 g

3 W
0 to 40 degrees C




The fixed decimal point may be selected to 7 places.
Switching the keyboard switch to the 'F'-postion gives floating
decimal point for addition, subtraction, multiplication and division. 
Round of is auto performed, only in the case of fixed decimal poin,
when [+=] or [-=] is depressed.
When the calculation is floating decimal point and exceeds 8 digits,
sufficient of the lower decimal digits will be disregarded to allow a
total display of 8 digits until a total of 8 digits whole number is reached,
all decimal digits have been disregarded.
More than 8 digits whole number will cause overflow.











For constant calculations, the constant switch is set to 'K',
For multiplication the first factor is constant, for division the second.
Unnecessary '0'-digits ahead of the numeral display are suppressed.
Setting the power switch to 'ON' auto opens the display hood and lights
the display ready for operation. Closing the display hood turns off the machine.
The carrying handle is slid out for carrying and fits under the machine when in
the closed position.



TAKAHARU, DENTAKU-museum
-

 

Example

Operation

Result

123+872-56.78

[Decimal Point switch]=2,
[C] 123 [+=] 872 [+=] 56.78 [+=]

938.22

2x5.14x12

[Decimal Point switch]=2,
2 [X] 5.14 [X] 12 [+=]

123.36

17880/4/360

[Decimal Point switch]=F,
17880 [division] 4 [division] 360 [+=]

12.347222

3 raising to power 3

[Decimal Point switch]=0, [K Switch]=On
3 [X] [+=] [+=]

 27

Constant calculation:
0.37x3
0.37x6
0.37x9

[Decimal Point switch]=2, [K Switch]=On
0.37 [X] 3 [+=]
6 [+=]
[+=]


1.11
2.22
3.33

Constant calculation:
5400/360
45000/360
99000/360

[Decimal Point switch]=F, [K Switch]=On
5400 [division] 360 [+=]
45000 [+=]
99000 [+=]


15
125
275

((9x8-27)/6)+12.34

[Decimal Point switch]=F
9 [X] 8 [+=] 27 [-=] [division] 6 [+=] 12.34 [+=]
19.84

Underflow:
1234.5678x12.345678

[Decimal Point switch]=F
1234.5678 [X] 12.345678 [+=]
15241.576