Collection Item

Home | Contact

Sharp QT-8D

Brand: Sharp.
Model: Micro Compet QT-8D.
Origin: Japan.
Introduction: 1969.
Type: Early basic desktop calculator.
Functions: 4-Basic function, no memory and no constant.
Display: 8 digit + Sign individual VFD Itron tubes.
Keyboard: 15 reed-switch keys and ON/OFF switch.
Main chips: Rockwell NRD2256, DC2266, AC2261, AU2271, all with date code 7031 (around July 1970) and Hitachi HD3103P with date code 0E (May 1970).
Logic comments: First LSI CMOS technology architecture used in an electronic calculator. It uses 4 chips manufactured by Rockwell in the USA but designed by Sharp, each counting around 1875 electronic components (now you can see more than 50,000,000 components on the same surface!). This architecture, with some changes, was used in other calculators like Sharp QT-8B (portable version of the QT-8D), Sharp EL-8 ("pocket-size" version of the QT-8D), EL-8M, EL-160, Burroughs C3260 and other OEM versions. Keyboard has an unusual layout and was reduced to a minimun key count: only 15 keys for all functions, including number input. A brief description of each key:

0-9 and . (decimal point): Numerals and decimal point keys. All this keys have an automatic locking system to avoid pressing more than one key at a time.

(Multiply-Divide): Use to multiply or divide if you complete the operation with += or -= respectively, see examples below.

+= (Add-Multiply): Use to add or complete a multiplication.

-= (Substract-Divide): Use to subtract or complete a division.

C (Clear): Clears the calculator.

Simple operation examples:
a) To compute 2+3 enter 2
+= 3 +=
b) To compute 2-3 enter 2
+= 3 -=
c) To compute 2*3 enter 2
3 +=
d) To compute 2/3 enter 2
3 :=
Remarks: The best machine of my whole collection!. Beauty design from the space era, robust and solid construction, top-quality plastics, big Itron display, very clear and readable. Bravo for Sharp!. Please see my Sharp QT-8B.
Size: 9.6 x 5.1 x 2.75 in, 245 x 130 x 70 mm.
Accesories: Leather-type carrying case, power cord, instruction manual and promotional brochure, all in very good condition!
Condition: (9.5/10) Excellent, pristine condition, full working, really a nice item from my friend Scott of California!
Download: Original Instruction Manual of the Sharp QT-8D. English, PDF format, Download
Promotional Brochure with the stamp of a dealer in Hollywood, California. English, 2 big JPEG images
Download Page 1, Download Page 2 .
Additional readings: You can read a complete article about the Sharp QT-8D here, from

Please see this Sharp QT-8D TV commercial from 1970 (Adobe Flash player required). Only 8 seconds long.

El contenido de esta página requiere una versión más reciente de Adobe Flash Player.

Obtener Adobe Flash Player


Home | Contact