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MADAS   Model 20 A
( ACRONYM = Multiplication, Automatic Division, Addition & Subtraction )

TECHNICAL DATA  of the  Full-Motorized  Electro-Mechanical  Calculator
                                                      MADAS Model 20 A
Serial Number:       74921

Dimensions:   (ca.)  Width   =  14_1/4" /  36 cm
                     Depth   =  12_1/4" /  31 cm
                     Height  =   8_3/4" /  22 cm

Weight:       (ca.)  35 lbs  /  16 kg

Power Supply:        220 V AC/DC ;  0.3 A   (* Motor ~360 Counts/Min )

Mechanics:           10*9 Full-Keyboard
                     StepDrum / Staffelwalze

Functions:           Add, Subtract, Multiply, Divide
                     Full-motorized Arithmetic!

Registers:           Arithmetic    =  20 Decimals
                     Counter       =  10 Decimals
                     Input         =  10 Decimals
                     Multiplicator =  10 Decimals
                     HANS W. EGLI
                     Fabrikation von Rechenmaschinen
                     ( O. Steiger, E.Jahnz, H.W.Egli )
                     Zurich / Switzerland

H O W   T O   U S E    the   MADAS 20 A
(*)  Motor Speed Adjustment after Replacement

Diagram shows a similiar MADAS-Version. Refer to GERMAN TEXT down ...

T H E   B A S I C S :

(A)  Registers:
(I)   ARITHMETIC Unit on top of the carriage.
      It can be pre-set by knobs on top - and deleted by key [I].
(II)  COUNTER. The +/- Lever on the right determines the counting
      direction UP (= default) or DOWN. Deleted by key [II].
(III) DISPLAY of the INPUT KEYS pressed. Deleted by key [III].

( O ) MULTIPLIER-DELETE. The MULTIPLIER can be pre-set by knobs.

(B)  Carriage:
Keys [->] / [<-] moves the carriage left or right by motor power.
The far left is the START-POSITION 1.

Example:     123 + 45 - 6  =  162

Clear input, counter and arithmetic units. Carriage in position 1.

ADD: Enter the 1st number (123) in the far right of the input unit.
Press [+] key to transfer the number into the arithmetic unit. The
counting unit displays the figure 1. Enter the second number (45).
Press the [+] key to add the number. The arithmetic unit displays
the intermediate sum (168) and the counting unit displays figure 2.

SUBTRACT: Enter the 3rd number (6). Press the [-] key. The arithmetic
unit displays result (162) and the counting unit is decreased by 1.

REMARK 1:    The ROUND Key ( over the DELETE-Keys ) is the REPEAT.
             It can be locked by pushing forward; released backward.
             The INPUT will NOT be cleared automatically.

REMARK 2:    NEGATIVE RESULTS are displayed in the arithmetic unit
             as the COMPLEMENT of the next higher 10, 100, 1000, ...

             Example:   -12  =  99...9988

Example:     123 x 45  =  5535

Clear input, counter and arithmetic units. Carriage in position 1.

Enter the multiplicand (123) in the far right of the input unit.
Press the BAR under the input unit to transfer it to the MULTIPLIER
REGISTER. The input will be deleted. Enter the multiplicator (45) in
the far right of the input unit and press the BAR again. The multi-
plication will be automatic calculated and the carriage returns in 
position 1.  The result is displayed in register (I) and the multi-
plicand (123) is displayed in register (II) ...

R E M A R K :  Using MULTIPLIER-PRESET-KNOBS can speed-up the task.

Example:     123 x 45 x 6  = 33210    ( continued )
To multiply a 3rd factor, press TRANSFER KEY [!] ( over clear keys )
to transfer former result in the MULTIPLIER REGISTER.  Enter the 3rd
factor (6), press the BAR again. The result is shown in register (I)
and the former, intermediate result is shown in register (II).

Example:     22 : 7  =  3.142857142   Remainder 6

Division requires 3 steps:

(a) Set the Dividend into Arithmetic Unit:
    For the maximum number of decimals, shift the arithmetic unit to
    the far right position. Enter the dividend (22) in the far left
    columns by PRE-SETing the arithmetic unit (I).

(b) Set the Divisor in the Keyboard:
    Enter the divisor (7) below the dividend (22).

(c) Divide:
    Press the [DIV] key and the machine will calculate all decimals
    (and moves the carriage) automatically. The result (3.142857142)
    is in the counter unit, and the remainder (6) in the arithmetic.

I N   G E R M A N  ...                                           
Bemerkung:  Model 20A hat KEINE "DividendenUebertragungsTaste" (Z) !!!




R E M A R K :     Excellent DETAIL-PICTURES of the INNER MADAS see ...

© C.HAMANN      01/27/15