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Calculators: Handheld: Sinclair Scientific Programmable

(c) Emil Dudek 2011

Size (actual):

76.0mm (max) x 156.4mm x 31.7mm (max)  (w,h,d)
Weight 138g excluding  batteries.

Power: 9.0V DC, 1 x PP3 size battery.  Also accepts an adaptor (undefined though I found 4.5V centre positive worked fine) through a top side socket on the left.  The manual states that it is designed to be used of the (included) adaptor, the battery is for only occasional use.
Case: Smooth matt black two piece plastic case with a raised upper area to accommodate the battery.   A neutral plastic display filter sits almost flush and lightly tilted towards the user. The logo, model number and a few extra key functions are printed in white text on the case.  The grey and dark olive keys are short-travel and make a positive click.
Display: 8 digit blue fluorescent display with a ninth used for error and minus indication
Features: Four standard functions, logs, trigs, register exchange, squares, square root, reciprocal, change sign, three function memory.  Full reverse Polish notation (RPN) logic. 24-step programmable.
Age: 1975
Manufacturer: Sinclair Radionics Ltd., made in England.  Serial number in battery compartment 4(or A?)702096.
Comments: Another classic British Sinclair calculator.  Same case as the Oxford range that is a very early (and very basic programmable).  The logic can be very strange at times with awful error states (i.e. none).  The original soft case is soft black plastic with a flip over flap and tuck-in band at the front.

Logic comments: The Clear key (C/CE) is used once to clear a number entry and a  second press performs an all clear
Overflow on the input of a number is suppressed, keying a sixth digit is ignored
Negative numbers are shown with a "-" in the far left (ninth) digit thereby allowing full five digit negative numbers
The only display configuration is 5-digit mantissa with 2-digit exponent.  You are limited to four digit fractional numbers unless you use scientific notation
Inputting a scientific number involves using the (./ee/-) key up to three times as it is amazingly a three-function key: 1.2-10 is entered by (1)(./ee/-)(2)(./ee/-)(1)(0)(./ee/-)()(enter) - for all those people that like RPN - you're talking rubbish!
There is no constant function
It is true RPN (Reverse Polish Notation) logic. to do 3+2 key in (C/CE)(3)()(enter)(2)(+) and 3x2 is (C/CE)(3)()(enter)(2)(X)
Higher functions are accessed by use of the shift key () - the most annoying part being that the (enter) function always requires this - when it is the most used function!
Overflow shows the shifted result and no exponent - and you just carry on
Divide by zero shows "0." and you just carry on
The memory functions are  ()(sto) for storing, ()(rcl) to recall and ()(x< >m) to exchange with the register 
Memory store is not indicated, you have to remember it
The programmable keys are (B/E) for begin/end, (EXEC) for run, (' ') for constants
It surprisingly does not suffer any negative zero bugs

(c) Emil Dudek 2011

The box is 195mm by 195mm by 27mm (w x h x d).  It is printed in silver and black.  There is an inner faux-felt lined plastic tray that has compartments for the calculator, battery and either the soft case or the adaptor.  There is no room from the programme library so this must have been supplied in separate packaging.  The Operating Manual measures 127mm x 166mm (w x h) has a silver and black cover and is printed black only throughout its 23 pages.  There is a pull-out flap with the picture of the calculator keys for reference.  Well written text in English only goes through the basic operations. The Programme Library consists of 49 (mostly double-sided cards).  The first (cover) continued the silver and black theme, whilst the rest are printed black only. The cards measure 127mm x 147mm (h x w) and are contained in their own clear plastic wallet.
My example is missing pages 9,26 and 43 but has two copies of pages 15,32 and 49 which tends to suggest that:
a) there was a packing error and the QA station used the weight as a check
b) the original owner did not catch it and return the library


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