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DATAMATH CALCULATOR MUSEUM

Technico SL-656

Date of introduction:	1985	Display technology:	LCD
New price:	$4.99 (SRP Dec. 1986)	Display size:	8
Size:	4.8" x 2.7" x 0.40" 122 x 69 x 10 mm³
Weight:	2.2 ounces, 62 grams	Serial No:
Batteries:		Date of manufacture:	mth 05 year 1986
AC-Adapter:		Origin of manufacture:	Taiwan
Precision:	8	Integrated circuits:	Toshiba T6853BU
Memories:	1
Program steps:		Courtesy of:	Joerg Woerner

Does this Technico SL-656 calculator look familiar to you? Inventa Electronics Corporation of Taipei, Taiwan started already in 1975 manufacturing and marketing calculators under the Technico brand. Inventa Electronics Co. is today known as Inventec Corporation, one of the World's largest manufacturers of mobile devices and computers. Inventa / Inventec was in the Eighties producing millions and millions of basic electronic calculators based on single-chip calculator circuits from established Japanese manufacturers like NEC, Sharp and Toshiba and Liquid Crystal Displays from Epson. Only a small fraction of these calculators were sold under the Technico brand, we know as of today 40+ corporate brand names for Inventa / Invetec OEM (Original Equipment Manufacturer) designs:

AEG Olympia, Asaflex, Benkson, Citizen, Clover, Commodoor, Digitech, Dixons, Dyna-Tone, Elco, General Electric, GKB, Gracia, Hanimex, Hercules, Idea, IMA, KMC, Levi, Lion, Logitech, MBO, M-Office, Olympia, Pacific Technology, Philips, Pierre Cardin, Precision, Printaform, Prinztronic, Privileg, Pulser, Quasar, Royal, Satek, Sears, Tecnosonic, Texas Instruments, Unisonic, Unitronic, and Vitronic.

We discovered the SL-656, and most important the SL-674CK, on our quest to learn more about the roots of the TI-1755 SLR introduced in 1983. While we found proof that TI-1754, TI-1755, TI-1756 and TI-1757 II are actually rebranded Inventa calculators, doesn't fit the TI-1755 SLR into the line. We decided for a thorough tear-down of the SL-674CK and the TI-1755 SLR to learn more about their relationship.

Dismantling the featured Technico SL-656 manufactured in May 1986 by Inventa Electronics Corporation in Taiwan reveals a clean design centered around a Toshiba T6853BU single-chip calculator circuit soldered on a double-sided printed circuit board (PCB) and powered by four solar cells. The T6853BU chip was used with the Technico F-800 and its offspring TI-2130, too.

Inspecting the PCB of the Technico SL-656 calculator brought our attention to a small mark reading IOSL656-02G. We found a similar PCB-Mark reading I074F-02B with the LC-741CK and started compiling a list of the PCB-Marks on calculators manufactured by OEMs for Texas Instruments.

If you have additions to the above article please email: joerg@datamath.org.