Sharp Model EL-1101, S/N 59003116
Functions: ASMD, K, percent, 1 memory
Technology: MOS-LSI (single chip), portable
Display: 10 digits, vacuum fluorescent module
Dimensions: 100W x 175D x 45H
Weight: 0.43kg including batteries
Manufactured: Sharp, Japan, June 1975.
The EL-1101 is a 10-digit portable calculator in a larger casing with metal trim panels, similar to the EL-816. It uses an early "flat-panel" fluorescent display module with 11 digits (10 numerals plus sign/overflow). Power is supplied from four disposable AA batteries, a special Ni-Cad battery pack, or an external AC adaptor and charger. The single-chip processor is an Hitachi HD3683.
EL-1101 External View
The calculator has a carry strap on the left-hand side of the case, and the power switch on the right.
The three slider switches select Constant mode, fixed or floating display, and roundoff mode. The keyboard and memory operate as expected.
EL-1101 Internal View
The battery compartment (at the rear) has a set of contacts on the top surface which enable the charging circuit when the special Ni-Cad battery pack is installed.
The keyboard is constructed from individual key switches mounted on a metal plate, and interconnected with a rigid printed circuit board.
The processor board mounts under the keyboard and extends about halfway along the case.
EL-1101 Logic and Display
The logic circuitry consists mostly of the HD 3683 processor and two resistor arrays. The keyboard connects via the flexible ribbon at the front.
The modular display panel in the centre of the board is a Futaba 11-ST-08A with a date code of 5F (June 1975).
At the rear of the board is the input connector for the external AC adaptor/charger (6VDC, 150mA), the power switch, and a couple of protection diodes. The inverter and power supply components are hidden under the display panel.