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Calculators: Handheld: Lloyd's Accumatic 321 (aka E321)

Size (approx): 85mm (max) x 136mm x 27mm (max)  (w,h,d)
Weight 150g excluding batteries.

Power:

6V DC with 4 x AA size batteries.  It accepts an adapter/charger (6V DC 300mW, Series 255A) through a socket on the top side to the far right.   Remove standard batteries before using an adapter.
Case: Square and solid design, the main body being made of a two piece beige gloss plastic shell.  A third section forms the two end panels in matt dark brown plastic which matches the front keyboard surround.  The latter has some white printed text for the on/off switch label.  The neutral display filter is proud, tilted upwards and again printed with white text for the brand and model number.  The large keys are squashy and wobbly with a faint click but work well to this day.
Display: 8 digit blue VFD with a ninth digit for negative and memory indicators.
Features: Four function with percentages, square roots, change sign, reciprocal, squares, brackets and four function memory
Age: 1975
Manufacturer: Lloyd's, made in Japan, serial number 51-184651.
Comments:

 

Solid quality calculator that has some useful functions.  The logic is sound with good recovery and only let down by negative square roots and the pseudo fixed decimal bug.  The original cover is soft black plastic with a top flap and front band tuck-in.  

Components: 1 x cpu: Rockwell A5501PB 7542  (week 42 of 1975) 42 pin staggered DIL , 0.6"width
1 x nine digit VFD unit: Futaba 9-CT-10 5K (October 1975) round faced single tube 
2 x transistors
3 x diodes
4 x capacitors
6 x resistors
2 x resistor arrays
1 x transformer: GEC 04B
Boards: The keyboard assembly (E321 5501 GICO Japan GK176-5) rests loosely on top of the battery compartment and half covers the main board (81R-C8P).  15 strong wires connect the two boards which are not fixed to the case.  The main board has a number of unused holes with component markings so I suspect this was a general PCB used for other models.
Construction: Held together by internal lugs only.  There is a small lever slot at the bottom end of the battery compartment that allows you to prize apart the rear section.  I only found this useful after you have popped the lugs on one of the sides.  You can do this by gently pushing in the rear section and levering open with a soft implement. The front will eventually lift off. Quite difficult so be careful not to damage your calculator.  Very similar to the Decimo Vatman series.

Logic comments: The (C/CE) key is used to cancel entry on the first press and clears the whole calculator on the subsequent
Overflow on the input of a number is suppressed, typing in a ninth digit ignores the last number
There is automatic constant on all four functions
Negative numbers are flagged by a "-" sign in the far left (ninth) digit thereby allowing full eight digit negative numbers.
A divide by zero shows "0.0.0.0.0.0.0.0." digit and is recoverable using (C/CE)
Overflow shows the result with all decimal points alight and is recoverable using (C/CE)
The change sign function can be used in mid number entry
Negative square roots are allowed and result in a negative answer
Memory store is indicated by the decimal point of the far left (ninth) digit
This calculator suffers the pseudo fixed decimal bug: try (1)(+)(0)(.)(0)(0)(0)(=) to give "1.000" which remains as a three digit decimal number until more digits are required