T E C H N I C A L   D A T A   of the Mechanical Calculator  THALES  »GEO/R«
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Serial Number:       GEO 159884                   ( right on base / front )

Dimensions:   (ca.)  Width   =   16_1/2" /  42 cm
                     Depth   =    9    " /  23 cm
                     Height  =    6_1/2" /  17 cm

Weight:       (ca.)  31 lbs  /  14 kg

Mechanics:           Pin-Wheel / Sprossenrad
                     10s Carry Mechanism

Functions:           Double-Calculator for Geo-Data Calculations
                     Add, Subtract, Multiply, Divide
                     Back-Transfer / Rueckuebertragung ( also cross-over !)

Registers:           CL/CR  Counter     =  2 x  8 Decimals (on Top)
                     IL/IR  Input       =  2 x  9 Decimals
                     AL/AR  Arithmetic  =  2 x 13 Decimals
Manufacturer:
                     THALES-WERK 
                     Rastatt / Baden
                     Germany
                     1960

H O W   T O   U S E   the  THALES  GEO/R
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The DOUBLE CALCULATOR is symmetrical shaped. Each calculator works like the
THALES-CER. The BACKTRANSFER-Lever (RED CAP) is located down behind crank.
Initialized together with the associated (right/left) INPUT-CLEAR-LEVER and
performed by turning the associated (right/left) ARITHMETIC-WING-NUT.
Because the CARRIAGE is "shiftable through", it is possible to BACKTRANSFER
the content of the RIGHT ARITHMETIC (AR) to the LEFT INPUT-UNIT (IL) or the
content of the LEFT ARITHMETIC (AL) to the RIGHT INPUT-UNIT (IR).
The DIRECTIONS OF COUNTING are settable independent: Equal, Non, Counter-
directionional  ---  Also the way the ARITHMETIC-UNITS working ref. to the
(left/right) MAIN-DIRECTION-LEVERs & CRANK (+/-) DIRECTION: Add./Sub.
The COUNTERs & ARITHMETICs are pre-settable with affiliated toothed wheels.


E X A M P L E :       ( 987 - 6 )*54 - ( 321 + 9 )*54  =  35154
                        ===              ===
              assume    AL      and      AR    are INTERMEDIATE RESULTS ...

Pre-Set ARITHMETICS                           AL =   987  &  AR =   321
Set INPUT-UNITS                               IL =     6  &  IR =     9
Set LEFT MAIN-DIRECTION-LEVER to MINUS
Set RIGHT MAIN-DIRECTION-LEVER to PLUS
Set BOTH COUNTER-DIRECTIONS to PLUS
Make ONE POSITIVE CRANK-Turn                  AL =   981  &  AR =   330

B A C K T R A N S F E R    AL -> IL  &  AR -> IR

P R O C E D U R E :  
(.L.) LIFT LEFT CLEAR-INPUT-LEVER & PULL RED-CAP-LEVER
      RELEASE LEFT CLEAR-INPUT-LEVER
      Turn LEFT ARITHMETIC-WING-NUT for LEFT BACKTRANSFER
      ( RED-CAP-LEVER snaps back )
(.R.) LIFT RIGHT CLEAR-INPUT-LEVER & PULL RED-CAP-LEVER
      RELEASE RIGHT CLEAR-INPUT-LEVER
      Turn RIGHT ARITHMETIC-WING-NUT for RIGHT BACKTRANSFER
      ( RED-CAP-LEVER snaps back )
                                              IL =   981  &  IR =   330
                                              AL =     0  &  AR =     0
Set LEFT MAIN-DIRECTION-Lever back to PLUS
Clear COUNTING-UNITS with its WING-NUTS       CL =     0  &  CR =     0 

M U L T I P L I C A T I O N :
Shift Carriage right to Position 2;  Make 5 POSITIVE CRANKs 
Shift Carriage left  to Position 1;  Make 4 POSITIVE CRANKs
Clear   IR = 0 
                                              CL =    54  &  CR =    54
                                              AL = 52974  &  AR = 17820
S U B T R A C T I O N :
Shift Carriage so, that AR is under IL 
BACKTRANSFER   AR -> IL                       IL = 17820  &  IR =     0
Shift Carriage back to "normal" Position      AL = 52974  &  AR =     0
Make ONE NEGATIVE CRANK-Turn                  CL =    53  &  CR =    53
                                              AL = 35154
                                                   =====

   Further INFO see ...  http://www.rechnerlexikon.de/artikel/Thales_Geo

                         Have a look at "Calculating Trickies" ...

INSIDE VIEW: With the BIG KNOB right on top a PAPER-HOLDER is to flip up ...

   ... thread-in the DUAL-POSITION-MARKERs before TOP-COVER replacement !!!
                                        ( see MARKS [ >>>>> ] & [ >>>>> ] )
impressum:
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© C.HAMANN           http://public.BHT-Berlin.de/hamann            04/18/17