Radio Shack EC-2001

		Home New Stuff Author Links Guest book Web-log	Adverts Bric-a-brac Calculators Components Ephemera Events	For Sale Glossary History Hit or Miss Radios Transport	Ultra Valves Wanted Metal Puzzles Clocks

Calculators: Desktop: Radio Shack EC-2001

	Size (approx):	150mm (max) x 165mm x 48mm (max) (w,h,d) Weight 300g excluding batteries
	Power:	3.0V DC, 2 x D size batteries. Also accepts adapter (Europe: 14-854 or 14-9854, Australia 14-9251) through top side socket on the right. There is a cautionary note on the back sticker that says "Caution: if you plan to use on AC adapter, remove batteries.".
	Case:	Compact desk top made in two-piece smooth plastic case of dark brown and beige. Light blue display filter is angled at about 45 degrees. Dark brown painted metal keyboard surround is prone to chipping. Button action soft but positive in grey, cream and orange colour scheme. Three nicely lined up switched for power on/off, constant enabled and floating/fixed 2 decimal point. Display shows a nice "comma" separating the thousands.
	Display:	10 digit blue/green VFD display with additional digit-space (on the far left) for memory, negative and error symbols.
	Features:	Four function plus three function percentages and four function memory. Item count.
	Age:	1979
	Manufacturer:	Tandy Corporation (the UK store name) Cat. No. 65-660. Made in Taiwan. Serial No. 115270 7A9.
	Comments:	Quite a nice little compact desktop machine with a clear display and nice buttons. Radio Shack sold through the Tandy shops in the UK. Surprising number of components at such a late date,

Components:	1 x cpu Texas Instruments TMC1073NL MSL 7910 (week 10 of 1979) 1 x 10 digit plus symbols single encapsulated VFD 2 x transistors 6 x diodes 8 x capacitors 12 x resistors 2 x resistor arrays 1 x transformer
Boards:	Main board is ref TC1-34.
Construction:	Remove the two screws in the battery compartment and the front lifts off. Main keyboard assembly and attached cpu board is then just lifted out. The two are joined together by 16 stiff copper wires.

Logic comments:	(C/CE) cancels an incorrect numerical entry, pressing a second time clears the calculator
	An overflow (or divide by zero) results in the display showing "0" and a left pointing arrow on the far left hand side. It is not recoverable.
	You can switch between floating decimal point and fixed two decimal points
	Minus sign is on the far left allowing full 10-digit negative numbers
	Input overflow is suppressed, typing in nine digits ignores the last one
	The memory flag is a small "M" on the far left hand side of the display
	It has switched constant on all functions
	Overflow in memory can cause a crash. Try continually adding "1111111111" into the memory. Eventually it will overflow and (C/CE) is ineffective. You must use (CM) to reset the calculator.