Elka 103 (orange)

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Calculators: Handheld: Elka 103 (red)

		Size (actual):	70mm x 137mm x 30mm (max, approx.) (w,h,d) Weight 120g excluding batteries
		Power:	6.0V DC, 4 x AA size batteries. Also accepts an adapter (undefined, but 4.5-6V centre positive works well) through a socket on the top side to the far right.
		Case:	Lovely solid red-backed calculator with smooth rear and matt black front piece. Metal panel with black printed text round the switch, in its own recess. Back top of calculator is raised by about 30 degrees and the red display filter raised even more with a "fine-line" design. This, however, lets in a lot of ambient light so reduces the contrast of the display. The lower front edge has the brand and model number printed in white. The keys are squishy, medium travel and work well enough.
		Display:	8 digit red LED with bubble lens and ninth digit for negative and memory indicators
		Features:	Four functions with percentages, square root and four function memory.
		Age:	This one is 1975 but the design goes back as far as 1973.
		Manufacturer:	Produced by ISOT, exporter: ISOTIMPEX. Made in Bulgaria. The serial number sticker is missing on my example.
		Comments:	Lovely solid calculator, especially for its age. Not many came from Bulgaria so this is a nice example of using cheaper labour zones during the price wars of the 70s. The logic is quite good with full recovery but let down by the pseudo fixed decimal bug and negative square roots. The original soft case is 3/4 side, top, 3/4 side zip, soft black plastic with cloth lining. Odd that the CPU board is printed with "E101" - looks like a generic board for all models. It also appears that this has a revision of the A5502PA Rockwell IC from my other 103 model - but I cannot tell the difference in the logic.

Components:	1 x cpu: Rockwell A5502PB 7548 (week 48 of 1975) 42 pin staggered DIL, 0.6" width metal capped dark grey ceramic 1 x nine red LED display with bubble lens 6 x transistors 4 x diodes 17 x resistors 5 x capacitors 1 x transformer TP024
Boards:	The small cpu board (E101M) sits loose above the main board/keyboard and is connected by a 23-way ribbon cable. Board are secured using the case fixing screws.
Construction:	Remove the four screws on the back. Two of these screws are hidden underneath the sticky "model number" label. The case easily separates, hinging the back to the right.

Logic comments:	(C) cancels an incorrect numerical entry, pressing a second time (C) clears the calculator
	Input overflow is suppressed; keying in a ninth digit is ignored
	It has automatic constant on all four functions
	Overflow shows the result with all decimal points alight and is recoverable using (C)
	Divide by zero shows "0.0.0.0.0.0.0.0." and is recoverable using (C)
	Negative numbers are shown with a “-“ in the far left (ninth) digit thereby allowing full eight digit negative numbers
	Square roots of negative numbers are allowed and result in a negative number
	Memory storage is flagged by the decimal point of the far left (ninth) digit
	Using the memory is a two-keystroke sequence. To add to the memory key in (M)(+), to recall (M)(=) etc.
	It suffers the pseudo fixed decimal bug: key in (1)(+)(.)(0)(0)(0)(=) to give “1.000” which remains a fixed three digit decimal number until more digits are required or you use multiply or divide

	The Elkas came with a hard plastic outer box. I'm not sure if this was the retail box, but it is good enough to be, and survive shipping internationally. It measures 85.25mm x 148.00mm x 44.00mm which just about fits the calculator in its soft case, so nothing else was supplied. It is black, softly stippled plastic with white printed text.