Adman L-0830T

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Calculators: Handheld: Adman L-0830T

		Size (approx):	68mm x 127mm x 17-22mm (w,h,d) Weight 76g excluding batteries
		Power:	9V DC, 1 x PP3 size battery. Accepts an adapter (undefined but 2mm plug) through socket on the top side at the far right. A notice on the back states "Battery must be removed when using AC adapter".
		Case:	Compact and cheap feeling design. Body made of two-piece black smooth plastic with two large brushed aluminium panels above the display and as a keyboard surround. The latter is printed black for the key labels. The upper section is much thicker to accommodate the battery and tilts the display by about 20 degrees. The red (wrap around) plastic display filter has a raised and silver printed logo - in futuristic computer font. The model number is on a sticker on the back. Keys are short travel clicking type that work very well.
		Display:	8 digit red LED with bubble lens with a ninth digit for negative indication
		Features:	Standard four functions with percentages
		Age:	1977
		Manufacturer:	A QC sticker on the back says "MFG W Pheng", made in Singapore. Serial No. 104073.
		Comments:	Ah! the age of cheap mass produced LED calculators at a time when everyone was jumping on the bandwagon. The logic is poor with no recovery, no cancel entry and the pseudo fixed decimal bug. Similar models can be seen on Same Calculator. And compare the insides of these fascinating calculators.

Components:	1 x cpu: Texas ZA0571 KFSP 7701 (date code week 1 of 1977) 28 pin DIL, 0.6" width 1 x 9 digit bubble lens LED; HP 7241622K made in Singapore 0 x transistors 1 x diode 0 x capacitors 0 x resistor arrays 4 x resistors
Boards:	The single cpu board (Ref K101 AW145249 Rev A ETCO Pat Pending No. 19916/75 KBA 190491) sits above the keyboard assembly.
Construction:	Difficult this one - be careful! Gently prize the back of with a blunt (wooden) instrument whilst squeezing the front in. The back will pop off.

Logic comments:	There is no cancel for last entry just (C) to clear the calculator
	Input overflow is suppressed, keying a ninth digit is ignored
	Negative numbers are shown with a "-" in the immediate left hand digit, travelling to the ninth to allow eight digit negative numbers.
	There is automatic constant on all four functions
	Divide by zero shows a flashing "0." and is not recoverable
	Overflow displays the result of the calculation flashing and is not recoverable
	It suffers from the pseudo fixed decimal bug: key in (1)(+)(0)(.)(0)(0)(0)(=) to give “1.000” which stays a s a fixed three decimal point number until more digits are needed or divide or multiply is used.


The box is printed silver and orange with the minimum of information on it. It is just about big enough to take the calculator at 70mm x130mm x 25mm (w x h x d). It is a top-tuck end type.	The very basic, four page, black only manual is also the minimum you could get away with. At 66mm x 99mm it is about as cheap and thin as you could make. It is a generic manual with the model details overprinted on the front page. Notice that the display on the drawing is incorrect - showing the ninth (far left) digit display "E" for error. The manual text correctly mentions the flashing display.	The scan above shows the calculator with the rear of the case removed. Only a few extra components: some resistors and a diode across the power supply to stop you plugging in the wrong polarity adapter. The board is attached to the front by melted plastic posts - about as cheap as you can make it - typical of this date.