Sharp EL-8: Difference between revisions

Sharp EL-8
Other names	Facit 1111, ADDO-X 9364
Manufacturer	Sharp
Introduced	1970
Calculator
Display type	VFD
Display size	8 digits
Programming
Other
Serial Numbers	1012099

Latest revision as of 09:49, 22 September 2023

The Sharp EL-8 was an early handheld calculator produced by Sharp starting around December 1970.

Special features[edit | edit source]

Since the calculator uses the Itron font tubes it does not feature leading-zero supression, to help with readability (e.g. it would display '00000001' to display '1').

The calculator uses separate 'minus equals' and 'plus equals' keys, as well as a single key for multiplication and division, this was common for the time period.

Internal design[edit | edit source]

The calculator uses 3 PCBs internally, one for the logic, one for the display, and another for the power supply, the logic board and display board slot into a card-edge connector mounted to the keypad assembly, with the power board being connected to the display board via a wired connector and mounted with screws.

The calculator uses a reed-switch keypad, Vacuum Fluorescent Displays (8x Itron DG10L and 1x Itron SP8A), and 9 Integrated Circuits, the Rockwell AC2261, AU2271B, DC1152A, NRD2256, the Hitachi HD3121, and the NEC μPD190C.

Sharp EL-8[edit | edit source]

The Sharp EL-8 came in the colors black and white.

Gallery[edit | edit source]

Powered on.
Bottom case.
Badge (#1012099).
Rear of internals (with battery-bypass capacitor mod).
Front of the internals.
Powered-on without the display cage, there is copper tape against the back of the tubes and without the tape having a connection to ground the tubes will light dimly and unevenly.
Top of the keypad cage.
Bottom of the keypad cage.
Display board assembly.
Top of the logic board.
Bottom of the logic board.
Top of the power supply board.
Bottom of the power supply board (with battery-bypass capacitor mod).

Carrying case[edit | edit source]

The Sharp EL-8 came with a carrying case, the zipper latches shut and the carrying handle can button into 2 positions, with the handle extended or retracted.

Front
Side, showing buttons

Sharp EL-81 Power brick[edit | edit source]

The Sharp EL-8 came with a Sharp EL-81 power brick for charging and powering the calculator.

Top of the power brick
Bottom of the power brick

EL-84 Battery[edit | edit source]

The Sharp EL-8's battery pack is a 7.2v rechargable nickel-cadmium (NiCad) pack made up of 6 AA-sized cells.

Sharp EL-84 Battery pack

Facit 1111[edit | edit source]

The front of a Facit 1111

ADDO-X 9364[edit | edit source]

Battery-bypass capacitor mod[edit | edit source]

To bypass the requirement of the battery pack you can put a capacitor across the battery terminals, a 470uf 16v cap is approximately what you want.

Battery-bypass capacitor in a Facit 1111

This mod uses D-SUB pins ("nixie pins") soldered to the capacitor, and the capacitor hot-glued in-place of the battery, to make the mod reversible.

@@ Line 56: / Line 56: @@
 == Facit 1111 ==
+<gallery perrow="0" widths="350" heights="350">
+File:Facit1111 Top.jpg|The front of a Facit 1111
+</gallery>
 == ADDO-X 9364 ==
@@ Line 67: / Line 70: @@
 == External Resources ==
-* []
+* [https://www.oldcalculatormuseum.com/sharpel-8.html Sharp EL-8 on The Old Calculator Museum]
+* [http://www.vintagecalculators.com/html/sharp_el-8.html Sharp EL-8, Facit 111, and Addo-X 9364 on the Vintage Calculators Web Museum]
+* [http://www.datamath.org/Related/Sharp/EL-8.htm Sharp EL-8 on the Datamath Calculator Musem]
+* [http://www.johnwolff.id.au/calculators/Sharp/EL8-8M/EL8-8M.htm Sharp EL-8, EL-8M on John Wolff's Web Museum]
 == See also ==

Sharp EL-8: Difference between revisions

Latest revision as of 09:49, 22 September 2023

Contents

Special features[edit | edit source]

Internal design[edit | edit source]