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Calculators: Handheld: House of Fraser 18F (made by Rockwell)

Size (approx): 74mm (max) x 150mm x 22mm (max)  (w,h,d)
Weight 122g excluding  batteries.
Power: 9.0V DC, 1xPP3 size.  Also accepts adapter (not defined) on top side:- on the left.
Case: Mixture of smooth and stippled matt dark blue plastic.  Raised and white painted button labels and House of Fraser logo overprinted on red LED plastic filter.  Quite modern in appearance compared to the contemporary Rockwell calculators.  Futuristic font used for the button labels makes this a loveable calculator.  On/off sliding switch is on the left side:- in the middle.  Buttons are proud lozenge-shape just like the brown Rockwell's.  Supplied with a black plastic padded case with tuck-in flap which looks quite expensive.
Display: 8 digit red LED with bubble lens.
Features: Basic four function with percentages and two function memory. 
Age: 1975/6
Manufacturer: Manufactured for House of Fraser by Rockwell International.  Assembled in the United Kingdom.
Comments: Whilst the (correct) manual calls this the 18F, the back label identifies this calculator as the 8F.  Rockwell made a series of calculators for the House of Fraser that were of similar design.  Quite difficult to use as the "equals" button is not at the bottom right.  Buttons have long travel but positive click.  This is a remodelled Rockwell 18R.  Oddly enough my example has a label on the back declaring it to be the model 8F.  This is either a manufacturing error - or someone has switched it over the years.

Components: 1 x cu: Rockwell B5000CB 7547 (week 47 of 1975), 42 pint staggered DIL
1 x 8 digit bubble lens LED module
2 x capacitors
2 x resistors
Boards: The main board (20167D67) is attached to the keyboard assembly with block connectors. These are electrically connected through 9 pins going into the block connectors.  It is connected to the plastic bracketed display unit via 17 thick wires.
Construction: Case is opened by two Philip's screws on the back, when removed the rear comes off easily.

Logic comments: (CE) cancels an incorrect numerical entry, pressing a second time (C) clears the calculator
An error results in the display lighting up all decimal points  Error is recoverable by use of (CE)
Divide by zero results in "0.0.0.0.0.0.0.0.".
Minus sign is to the immediate left of a number, thereby limiting you to seven digit negative numbers.
Input overflow is suppressed, typing in nine digits ignores the last one
There is no memory flag - you have to remember it
It has automatic constant on all functions
It suffers the pseudo fixed decimal bug: (1)+(0)(.)(0)(=) gives "1.0" which remains a fixed two digit decimal number until multiply or divide is used.
To correct an erroneous operator press [1] for X or / , or [0] for + or -, obvious really !

House of Fraser 18F manual

Manual (in English only).   Front page shown is in gold ink, printed as two colour.  16pp fan-fold booklet with excellent picture to describe button function.

Ref: 2520-D-112 New 8-75, 226 R11-014