Sharp Elsimate EL-215

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Calculators: Handheld: Sharp Elsimate EL-215

		Size (approx):	77mm x 130mm x 20mm (max) (w,h,d) Weight 126g excluding batteries
		Power:	3V DC, 2 x AA size batteries, 0.35W. Also accepts adaptor/charger (EA-17E, 3V with battery pack EA-18B, 2.4V ) through a socket on the top side to the far left. The on/off switch is on the left hand side in line with the Sharp logo. Manganese battery lifetime is quoted as 12 hours which were supplied on purchase.
		Case:	Slim two piece plastic case, the front being white smooth plastic and the back brown smooth plastic. Small brushed aluminium plate above the display is printed black and grey for the company name and model number. A green plastic display filter is flat and flush and gives a reasonable display - letting in a bit too much light. They keys are squishy but work well. The keyboard surround has embossed "memory" around the top smaller keys.
		Display:	8 digit green VFD with a ninth (right-most) digit used for minus, memory and error indictors
		Features:	4 function calculator with percentages, square root and five function memory
		Age:	1980
		Manufacturer:	Sharp Corporation. Made in Korea. Serial number 0824509Y is on a sticker on the inside of the battery compartment.
		Comments:	Typical later compact Sharp that fits quite well in the hand especially with the on/off switch at perfect thumb position. White bodies on these type of models always fade badly in my experience. Odd right hand digit use for error flags and minus is common to Sharp. The logic is very sound with fair recovery and no detectable bugs. At such a late date it is odd to see the high component count and the use of metal panels in the keyboard design. The original case is soft smooth black plastic with open top and half-moon cut-outs either side. It is embossed with Sharp on the front. This must have been one of the last VFD calculators. Similar to the Sharp EL215A.

Components:	1 x cpu: Sharp LI2026A 0K5 004 (October 1980 date code), 28 pin DIL, 0.6" width black plastic 1 x 9 digit VFD; single glass tube flat faced, Futaba 9-ST-20 0E (May 1980 date code) 1 x transistor 4 x diodes 5 x capacitors 3 x resistors 1 x transformer; Sumida 1585
Boards:	The main cpu board (F1746A) is fixed to the keyboard assembly by the three ribbon cable screws and is joined by a 16-way ribbon cable. The keyboard assembly is metal backed, very sturdy and fixed to the front with one screw.
Construction:	Remove the two screws from the back. Quite difficult to open without damage. The best way appears to be by levering out the two lugs on the top side and hinging from the bottom two lugs.

Logic comments:	The (CE) button is used to clear last entry of a number and the (C) to clear the whole calculator.
	Overflow on number input is suppressed, typing in a nine digit number ignores the ninth digit
	An overflow shows the result and "C" ("E" if negative) in the far right (first) digit and is recoverable using (CE)
	Divide by zero shows "0.C" and is not recoverable
	There is automatic constant on all four functions
	Negative numbers are flagged by a "-" sign in the far right (first) digit thereby allowing full eight digit negative numbers.
	Negative square roots are not allowed give you "0.C" which is not recoverable.
	When memory store is in operation the far left (first) digit decimal point lights up
	Overflow in memory is flagged as an overflow and leaves the original memory content intact
	The (X>M) key does not exchange the memory with the current display, but replaces it.

	This image (left) shows the rear of the case removed. Notice the thin ribbon connector to the keyboard assembly at the bottom. A metal plate is used as a clamp to hold this in place which is a surprisingly expensive way of doing it. The more normal thick connector does not normally need this. It also holds the main board in place above the keyboard assembly. Note also the two blue electrolytic capacitors at the bottom, mounted off-board to minimise the thickness.		This image (left) shows the main board unfixed by removing the three screws. The black plastic spacer is set aside (towards the bottom) so you can see the fixing posts. Rather a messy designed board with a large number of link wires. Notice the metal plated keyboard assembly at the bottom, unseen is yet another thin ribbon cable/connector joining the contacts.
		The manual measures 126mm by 77mm and is an eight-sided fold-out construction. Printed in brown is surprisingly manages good instructions and specifications in four different languages (FIGS). Printed in Korea (TINSM3019CCZZ)