New Stuff
Guest book


For Sale
Hit or Miss
Metal Puzzles


Calculators: Handheld: Rapid Data Rapidman 800

Size (approx): 80mm x 140mm x 22mm  (w,h,d)
Weight 144g excluding batteries
Power: 9.0V, 1 x PP3 size battery.  It accepts an adaptor (undefined, centre +ve) through a socket on the top side to the far left. 
Case: It is made form a one-piece, brick shaped black plastic case with patterned black plastic except for s glossy designed section of the front.  The plastic is softer than the normal hard plastic cases making it feel a bit rubbery.  The smooth panel at the top has gold printed lettering and brand logo.  The red display filter is linearly convex, acting as an additional magnifying lens. It is deeply set in but mounted flat.  The display is bright and clear but of somewhat limited viewing angle. The keys are very odd, appearing to be attached to the case at the top only  and rocking down with short travel and a loud click.  A large gold-coloured metallic sticker nearly covers the whole back with instructions.
Display: 8 digit red LED with bubble lens and a ninth for negative indication.  There is also an additional red LED for overflow indication. 
Features: 4 function calculator. semi-RPN logic.
Age: 1972
Manufacturer: Rapid Data Systems and Equipment Ltd, made in Canada, serial number 435180.  I have also had serial number 433267 with IC date code 7219.
Comments: Strange early calculator that uses unique one-piece soft plastic case, odd lever keys, fixed two decimal point display and archaic logic.  Negative zero bug and divide by zero hook-up shows the early age of the IC.  However, the display is clear (whilst limited in viewing angle) and the whole package compact.  Interestingly, the on/off switch is a sliding switch that puts pressure on a standard key popper rather than a sliding contact.  Inside the construction is gloriously compact.  I know that this calculator was available in white and I think green as well.

Components: 1 x cpu; Mostek MK5010P C747 7232KYT (week 32 of 1972), 40 pin DIL, 0.6" width
3 x 3 digit red LED modules with bubble lens
1 x isolated red LED
24 x transistors
17 x diodes
5 x capacitors
39 x resistors
Boards: The main cpu board (RDC) sits on top of the keyboard assembly (Texas Instruments IKS108 2nd Issue) and is joined via 19 strong wires with paper banding.  This whole subassembly sits in a plastic frame that is removed by undoing three screws at the top.  You can then slip the assembly out of the frame for closer examination.
Construction: Remove the two screws from the back and rear of the case will lift off - hinging from the bottom as it is a one-piece moulded case. 

Logic comments: The (C) button is used to clear the calculator there being no cancel entry function.
Strangely, the display defaults to two digit decimal places; i.e. entering (5) will result in the display of "5.00".  This means that if you key in a seven or eight digit number you will get the overflow light but you can still carry on calculating.
Overflow on number input is not suppressed inputting a ninth digit causes an unrecoverable overflow.
An overflow shows the result with the Overflow LED alight.  You can divide by 100 to recover the answer except when the result exceeds ten digits when the display will read "" which is not recoverable.
Divide by zero results in no display at all and is not recoverable
There is no constant ability on any function
Negative numbers are shown by a "-" in the far left (ninth) digit thereby allowing full eight digit negative numbers.
It operates Reverse Polish Notation which takes a little getting used to: to perform 3-4 key in (3)(+)(4)(-) to give"-1"
The calculator suffers the negative zero bug; key in (1)(+=)(2(-) to give "-1" now add one with (1)(+=) to give "-0"


The scan on the left shows the box - well actually the printed sleeve that surrounds the polystyrene shell that the calculator and a 9V battery were supplied in.

It measures approx 105mm by `90mm and is 45mm deep.  Printed in full colour this sleeve shows the green version; did they all?  Also, the image shows the on/off switch in the off position.

Designed and manufactured in Canada.

Price sticker says ?25.00 (Mison's).

This scan shows the fabulously crammed main cpu board.  The large component count and white ceramic IC package are strong indications that this is a very early 70s pocket calculator.

Notice that the display is made up of three separate three-digit modules and that all of the components are mounted vertically to save space.

The shrouded wires you can see on the far left are the connections to the keyboard assembly.