MBO 3010

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Calculators: Handheld: MBO 3010

		Size (approx):	63-70mm x 135mm x 18-23mm (w,h,d) Weight 68g excluding batteries
		Power:	9.0V DC, 1 x PP3 size battery. It accepts adapter (9V DC BV 57 or BV 116, centre positive, 330mW) through a socket on the left side in line with the display. The battery compartment has a light blue ribbon pull to aid battery removal. The on/off switch is on the right hand side, in line with the display. Battery life is quoted as 20 hours for standard batteries and 50 hours for alkaline.
		Case:	Thin, black and grey glossy plastic two-piece case. A large oversized red plastic display filter is slightly inset and tilted with the wedge-shape of the calculator. This holds a large black and blue printed metallic sticker in its own recess with the brand and model number. An inset keyboard surround of brush aluminium appearance is printed blue and black for the key labels and highlights. The keys are short travel with a loud plastic click.
		Display:	8 digit red LED with individual bubble lens but with no extra digit
		Features:	4 standard functions with percentages, change sign and four function memory
		Age:	1979
		Manufacturer:	MBO Scmidt & Niederleitner GmbH & Co. KG. D 8024 Deisenhofen-Oberhaching, Munchen, Germany. Serial number 056025.
		Comments:	Cheap feeling calculator which is not helped by the clunky keys and very limited viewing angle display. There are many similar model listed on the Same Calculator page but they are more normally in black plastic only. The original case is soft black plastic with an open top. For such a late date the logic is poor with seven digit negative numbers and the pseudo fixed decimal bug.

Components:	1 x IC: Texas TMS0972NL MBT 7936 (week 36 of 1979), 28 pin DIL, 0.3" width 1 x 8 digit LED module with individual bubble lens
Boards:	As basic as you can get with one main board (SH-2 REV A) set with two plastic pillars in the base , attached to the keyboard assembly via ten long wires.
Construction:	Difficult top open as this was never designed to be repaired. There are numerous plastic lugs along all the edges. Best success was found starting at the sides pushing the upper section inwards. If in doubt -don't do it!

Logic comments:	(CE) cancels the last number entered whilst (C) clears the whole calculator
	Input overflow is suppressed; inputting a ninth digit is ignored
	There is automatic constant on all four functions
	Negative numbers are represented by a "-" sign in the immediate left hand digit. As there is no ninth digit to travel into you are limited to seven digit negative numbers
	The change sign function can be used in mid number entry and before
	Overflow shows the result flashing and is recoverable using (CE)
	Divide by zero results in a flashing zero which is recoverable using (CE)
	There is no indication of memory store - you have to remember it!
	Overflow in the memory wipes the contents after recovery using (C)
	This calculator suffers the pseudo fixed decimal bug; try entering (0)(.)(0)(0)(0)(+)(1)(=) to give "1.000" which remains a three decimal number until greater precision is required.

The manual on the left measures112mm by 65mm and is 16 printed pages in black only, In German and English, it has a surprisingly in depth instructions and examples. The back page is the six month warranty it was originally supplied with.