Collection Item 

Canon Canola 120
Brand:  Canon. 
Model:  Canola 120. 
Origin:  Japan. 
Introduction:  1969, this example was built in 1969, based on datecodes stamped on main chips. 
Type:  Basic desktop calculator with nixie tubes display, no battery support, operates only with AC power. 
Functions:  4Basic function, no constant and no memory. 
Display:  12 nixie tubes display plus 1 special lamp for Overflow indication. No negative indication! 
Keyboard:  17 reedswitch keys, sliding switch for decimal point selection (0, 2 or 4 decimals). On/Off switch. 
Main chips:  Texas Instruments: 3 x SN4554N (all with datecode 6918, around April 1969), 2 x SN3925N (datecode 2926, around June 1969) and one chip T4021A (brand?) without datecode. 
Logic comments:  Pseudo RPN notation, very used at the beginning of the 70s. For example: 2+3 you must type 2 Black = 3 Black =, for 23 you type 2 Black = 3 Red =. Brief description of each key: 0 to 9 and . (period): Numerals and decimal point key. X (Multiply): Use to multiply two numbers. รท (Divide): Use to divide two numbers. Black = (PlusEqual): Used to add a number to the display register. Also used to complete a multiplication and division, adding the result to the display register. Red = (MinusEqual): Used to subtract a number from the display register. Also used to complete a multiplication and division, subtracting the result from the display register ( See Negative numbers below). CI (Clear Input): Clears the last entered number or clears the overflow condition. C (Clear): Clears the machine. Decimal point selection switch: Selects between 0, 2 or 4 digit after decimal point. Negative numbers: Are represented by the 9complement system. For example: 5  9 (type 5 Black = 9 Red =) gives 999999999996, the 9complement representation of 4 with 12 digits. If you press Red = again you will see this result with positive sign, I mean: 4. This is described at the instruction card as the "antilogarithm", actually is the absolute value. This is the first electronic calculator I have with this negative number representation, identically to the Curta! Please see examples on the instruction card, you can download it from this page. 
Size:  13.19 x 10.24 x 3.74 in, 335 x 260 x 95 mm. 
Accesories:  Hard carrying case with handle, dust cover, original instruction card, nondetachable power cord.. 
Condition:  (9/10) Very Good to mint, no yellowing, imperceptible marks on casing, full working. 
Download:  Original instruction plastic card: Page 1, Page 2. 