MELITTA  IV/16
Have a Look at the WORKSHOP (B):   MELITTA_VI/16

Have a Look at the   MELITTA_VII/16
 ```The LOWER DECIMAL SLIDER & MARKERS and the BACK-TRANSFER CAP are home made T E C H N I C A L D A T A of the Mechanical Calculator MELITTA ************************************************************************** Model » IV/16 « Serial Number: 73209 Dimensions: (ca.) Width = 12 " / 30 cm Depth = 5_1/4" / 13 cm Height = 5_1/4" / 13 cm Weight: (ca.) 9 lb / 4 kg Mechanics: Pin-Wheel / Sprossenrad 10s Carry Mechanism Functions: Add, Subtract, Multiply, Divide Back-Transfer / Rueckuebertragung Registers: Input = 10 Decimals Counter = 8 Decimals Arithmetic = 16 Decimals Manufacturer: FORTUNA-WERK VEB Suhl / Thueringen Germany 1955 H O W T O U S E the MELITTA IV/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) Shifting the Carriage: -------------------------- With the ARROW KEYS the carriage will move one step to the LEFT or RIGHT. Pushing the LEFT BLACK KNOB on front allow the carriage to be moved by hand continuously right or left. The left position "1" is the "Start Position" of the carriage. (c) Clear Input: ---------------- Moving the SILVER HORIZONTAL LEVER up will reset the input to 0000000000. (d) Clear Counter and Arithmetic Units: --------------------------------------- Unusual: CLEARING needs TWO(2)TURNS of the carriage's crank. Moving the build-in lever in the crank's shaft (= CLEAR-SELECT-LEVER ) allow 3 axial positions: In the far left position only the counter unit will be cleared. In the middle position counter & arithmetic units will be cleared. In the far right position only the arithmetic unit will be cleared. (e) Counting Direction: ----------------------- After clearing, the (+/-) lever (on top, left) is in the middle position. Depending of the first crank turn (clockwise or counter- clockwise), the (+/-) lever will go either to (+) or (-). In case of (+) the counter & arithmetic unit are working in the same direction; in case of (-) both are working opposite. In both cases the counter is working with 10s-carry - and allows "Shortened Method of Multiplication". (f) Back Transfer: ------------------ For continuous multiplication the contents of the arithmetic unit can be back transfered into the input register with this procedure: Clear input unit. Set CLEAR-SELECT-LEVER to the right. Shift and hold the RED LEVER under the arithmetic unit and turn the crank on the carriage until the transfer is completed and the crank snaps in its rest. Release the RED LEVER. ADDITION & SUBTRACTION: ======================= Example: 123 + 45 - 6 = 162 Clear input, counter and arithmetic units; set carriage to position 1. ADD: Enter the first number (123) in the far right of the input unit. Make a positive (clockwise) turn with the crank to transfer the number into arithmetic unit. The counting unit displays the figure 1. 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: 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 MULTIPLICATION: =============== Example: 123 x 45 = 5535 Clear input, counter and arithmetic units. Enter the multiplicand (123) in the far right of the input unit. The multiplicator (45) has two digits, so the carriage is shifted to position 2. Make positive (clockwise) turns with the crank, until the first figure of the multiplicator (4) will appear in the 2nd position of the counter unit. Shift the carriage to position 1. Repeat making positive turns with the crank, until the second figure of the multiplicator (5) appears in the 1st position of the counter unit. The multiplication is done: The multiplicand (123) stays in the input unit, the multiplicator (45) in the counter and the result (5535) is in the arithmetic unit. DIVISION: ========= Example: 22 : 7 = 3.1428571 Remainder 3 Division requires 3 steps: (A) To Set the Divisor into Input Unit: --------------------------------------- Clear arithmetic, counter & input units. Enter the DIVISOR (7) in the far right of the input unit. (B) To Set the Dividend into Arithmetic Unit: --------------------------------------------- For the maximum number of decimals, pull out the carriage to the far right. Set the DIVIDENT (22) into the arithmetic unit with the affiliated toothed wheels appropriately under the divisor. (C) To Divide: -------------- Set the counting direction to (-). Make negative (counter-clockwise) turns with the crank until the arithmetic unit shows an "underflow". Make one positive (clockwise) turn with the crank. Move the carriage to the next left position. Repeat this procedure until the required number of decimals ... The result (3.1428571) is in the counter unit, and the remainder (3) is in the arithmetic unit. The divisor (7) stays in the input unit, therefore an additional decimal can be estimated... ( 4, cause 4 x 7 = 28). Have a look at "Calculating Trickies" ... impressum: ************************************************************************** © C.HAMANN http://public.beuth-hochschule.de/~hamann 02/01/08 ```