T E C H N I C A L D A T A of the Mechanical Calculator FACIT CM2-16 ************************************************************************* Serial Number(s): 1003640 (=Label outside) 753793 (=Engraving inside) Dimensions: (ca.) Width = 13_1/2" / 34 cm Depth = 11 " / 28 cm Height = 6_1/4" / 16 cm Weight: (ca.) 17_1/2 lbs / 8 kg Mechanics: 10-Block-Keyboard, Serial-to-parallel conversion with Pin-Wheel / Sprossenrad 10s Carry Mechanism Functions: Add, Subtract, Multiply, Divide Double Back-Transfer / Rueckuebertragung Registers: I Input = 11 Decimals II Counter = 9 Decimals III Arithmetic = 16 Decimals Manufacturer: FACIT Atvidaberg Sweden 1960 H O W T O U S E the FACIT CM2-16 **************************************** BASIC SETTINGS: =============== (A) Crank: ---------- For addition (+) the crank is turned clockwise; for subtraction (-) the crank is turned counter-clockwise. In the idle position the crank is DOWN & LOCKED. To make one or more turns with the crank, pull out the handle to unlock. When finished the turn(s), let the handle snap into lock again. The locked down position only makes other functions (ex. clearing) accessible. REMARK: Every started turn has to be finished completely! Accidentally started turns are correctible somehow. (B) Clearing Arithmetic Unit, Counter & Input: ---------------------------------------------- On the left side the LEVER-PAIR is for clearing registers (III)&(II) by pressing down the left or right lever (or both). The LEVER on the right side will clear and reset the input unit (I) by pushing it backward (with thumb on lever and index finger on crank axle). REMARK: Prior to each task, reg.(I),(II)&(III) have to be cleared. (C) Shifting the Input Unit with the Entered Number: ---------------------------------------------------- Left of the number keys, the RED KEY-PAIR let the input unit STEP left [<-] or right [->]. The actual position is marked with a (white) DOT above the counter. Right of the 10-Block keys, the RED [<16] KEY and the RED [<11] KEY let the input unit JUMP to the left positions. With the [<11] KEY the counter stays in 1st position; with the [<16] KEY the counter jumps to 8th position. In both cases the input unit will be filled up with zeros. (D) Counting Direction: ----------------------- After clearing the counter unit (II), it depends of the first crank turn (clockwise or counter-clockwise), that the counter will go either (+) or (-). In case of (+) the counter & arithmetic unit are working in the same; in case of (-) both are working in opposite direction. This is shown with a RED INDICATOR at the left of the counter unit. (E) Back Transfer: ------------------ The single handle on the left side is the TRANSFER LEVER. Pulling it down will (depending where the input unit is located): (A) Transfer a result from the arithmetic unit (III) into input unit (I). (B) Transfer a quotient from the counter (II) into input unit (I). The former content of the input unit (I) will be overwritten and the registers (III) & (II) are cleared. Transfers are useful for continuous multiplications or shifting a sequence of figures from an interim result. REMARK: Is the content of register (III) bigger than register (I), ONLY THE FRACTION opposit to reg.(I) will be transfered! ADDITION & SUBTRACTION: ======================= Example: 123 + 45 - 6 = 162 ADD: Enter the first number (123) into input unit. Make a positive (clockwise) turn with the crank to transfer the number into arithmetic unit. The counting unit displays the figure 1. Clear the input unit. Enter the second number (45). Make a positive (clockwise) turn with the crank to add the number. The arithmetic unit displays the intermediate sum (168) and the counting unit displays the figure 2. SUBTRACT: Clear the input unit. Enter the third number (6). Make a negative (counter-clockwise) turn with the crank. The arithmetic unit displays the result (162) and the counting unit is decreased by 1. REMARK: NEGATIVE RESULTS are displayed in the arithmetic unit as the COMPLEMENT of the next higher 10, 100, 1000, ... Example: -12 = 99...9988 REMARK: The POSITIVE VALUE can be derived in 2 steps: (A) BACK TRANSFER from reg.(III) into reg.(I) (B) One NEGATIVE TURN with the crank... Example: = 99...0012 MULTIPLICATION: =============== Example: 123 x 45 = 5535 Enter the multiplicand (123) into input unit. Make positive (clockwise) turns with the crank, until the second figure of the multiplicator (5) will appear in the 1st position of the counter unit. Move the input unit with the STEP [<-] key to position 2. Repeat making positive turns with the crank, until the first figure of the multiplicator (4) appears in the 2nd position of the counter unit. The multiplication is done: The multi- plicand (123) stays in the input unit, the multiplicator (45) is in the counter and the result (5535) is in the arithmetic unit. DIVISION: ========= Example: 22 : 7 = 3.14285714 Remainder 2 Division requires 3 steps: (A) To Set the Dividend into Arithmetic Unit: ----------------------------------------- Enter the dividend (22) into input unit. Press the JUMP [<16] key. Make a positive (clockwise) turn with the crank to transfer the input into arithmetic unit. (B) To Set the Divisor into Input Unit: ----------------------------------- Clear input and counter unit. Enter the divisor (07) into input unit. Press the JUMP [<16] key. (C) To Divide: ---------- Make negative (counter-clockwise) turns with the crank (now the red indicator is on) until the arithmetic unit shows an "underflow". Make one positive (clockwise) turn with the crank. Move the input unit with the STEP [->] key one position to the right. Make negative turns again ... and repeat this procedure until the required number of decimals are calculated... The result (3.14285714) is in the counter unit, and the remainder (2) is in the arithmetic unit. The divisor (7) stays in the input unit, therefore an additional decimal can be estimated... ( 2, cause 2 x 7 = 14). impressum: ************************************************************************* © C.HAMANN http://public.beuth-hochschule.de/~hamann 08/24/07 |