John Wolff's Web Museum

Early Sharp Calculators


 

Contents

CS-743 printing calculator
Sharp CS-743 printing calculator, 1973

Overview

The Sharp company of Japan takes its name from the "Ever-Sharp" propelling pencil invented by founder Tokuji Hayakawa in 1915.

Sharp is credited with many of the "firsts" in the early development of electronic calculators, including a fully-transistorised 10-key machine (the CS-10A) in 1964, the first MOS-LSI calculator (the QT-8D) in 1969, the first battery-powered portable calculator (the EL-8) in November 1970, and the first portable LCD calculator (the EL-805) in 1973.

The Sharp calculators on this page show the rapid progress that was made during the early years of the 1970s - not only in integrated circuit technology, but also in keyboard and display systems, power supplies, and the development of a consistent user interface.

Click on the pictures for larger illustrations, and follow the links for further information.

 

Portable Calculators

EL-8 external view Sharp Model EL-8, S/N 020054Y
Functions: ASMD
Technology: MOS-LSI (4 chips), portable, NiCad battery
Display: 8 digits, vacuum fluorescent tubes
Dimensions: 102mm W x 164D x 70H
Weight: 0.72kg including batteries
Manufactured: Sharp, Japan, December 1970.

While the Sharp QT-8B desktop calculator was probably the first electronic calculator to be fitted with internal rechargeable batteries, the Sharp EL-8 from November 1970 was the first to be designed specifically as a portable battery-operated machine. It was advertised at the time as being "the smallest electronic calculator in the world".

The calculator uses a set of four Rockwell MOS-LSI chips in 42-pin flat-packs. The display uses eight individual vacuum-fluorescent tubes, with shaped digits and a distinctive half-height zero. The keyboard uses glass reed switches operated by moving magnets attached to the ends of the keystems. Power is supplied from an internal battery pack (EL-84) containing six AA NiCad cells, with a specialised external charger type EL-81.

One of the charming features of early calculators is the lack of standardisation in the user interface. The EL-8 has both Multiply and Divide marked on the same key - which one you get depends on which Equals key you press afterwards!    More...

 

EL-8M external view Sharp Model EL-8M, S/N 1228915
Functions: ASMD, 1 memory
Technology: MOS-LSI (4 chips), portable, NiCad battery
Display: 8 digits, vacuum fluorescent tubes
Dimensions: 102W x 185D x 70H
Weight: 0.75kg including batteries
Manufactured: Sharp, Japan, April 1971.

The EL-8M from April 1971 is basically an EL-8 with the addition of a single memory register and an extra row of keys. The case has been lengthened by 20mm to accommodate the additional memory keys.

The "M/D" key at the top right switches between memory functions and a "double-precision" mode, in which the calculator can multiply two 8-digit numbers and produce a 16-digit result.    More...

 

EL-811 external view Sharp Model EL-811A, S/N 3005101
Functions: ASMD, K, 1 memory
Technology: MOS-LSI (2 chips), portable, NiCad battery
Display: 8 digits, vacuum fluorescent tubes
Dimensions: 105W x 175D x 45H
Weight: 0.56kg including batteries
Manufactured: Sharp, Japan, 1972.

The Sharp EL-811 is a portable battery-powered calculator from 1972. Although only a year later than the first battery portables (the EL-8 and EL-8M above), it shows significant advances in the circuitry, styling, and operator interface.

The calculator has a large wedge-shaped case with brushed metal trim panels and a carrying strap on the left-hand side. The internal construction is very similar to the EL-8. The keyboard now has separate multiply and divide keys, and a double-arrow key to switch between the upper and lower parts of a double-precision result. The display still uses individual VFD tubes (Futaba DG10Q1), but with rectangular 7-segment numerals and a full-height zero. The circuitry uses only 2 processor chips and 3 display drivers, instead of the previous 4 and 9. Power is supplied from the same internal NiCad battery pack and external charger as the EL-8 and 8M.    More...

 

EL-816 external view Sharp Model EL-816, S/N 3020539
Functions: ASMD, 1 memory
Technology: MOS-LSI (single chip), portable, NiCad battery
Display: 8 digits, vacuum fluorescent tubes
Dimensions: 105W x 175D x 45H
Weight: 0.57kg
Manufactured: Sharp, Japan, 1973.

The EL-816 from 1973 is externally very similar to the EL-811 (above), except for the addition of a "K" key for manual control of the Constant function. The entire keyboard has been moved slightly forward to make space for an additional row of keys.

The display uses individual fluorescent tubes with rectangular 7-segment characters. (The DG10FL tubes actually contain an eighth segment at the centre right to display a "proper" crossed 4, but this segment is not used in the EL-816). The circuitry has been further simplified, with only a single Rockwell 15340 processor chip and two display drivers, all mounted on one single-sided board. The calculator is powered from the same internal Ni-Cad battery pack and charger as the EL-8 and EL-811.    More...

 

EL-8102 external view Sharp Model EL-8102, S/N 4204246
Functions: ASMD, percent, square root, 1 memory
Technology: MOS-LSI (single chip), portable
Display: 8 digits, vacuum fluorescent tubes
Dimensions: 105W x 175D x 50H
Weight: 0.60kg
Manufactured: Sharp, Japan, 1973.

The EL-8102 is externally similar to the EL-816, but has separate keys for plus, minus, and equals. The double-precision mode and shiftable display have been deleted, and the keys replaced with square root and percentage. The single-chip processor is an NEC uP0277C.

The EL-8102 has an externally-accessible removable battery pack fitted into the underside of the case. The standard pack accomodates six disposable AA batteries, with provision for a 9V 200mA DC plug pack (type EA-13A) for mains operation. An EL-95 NiCad battery pack with six 450mAh batteries was available as an option, with the same EL-81 charger as the earlier 6-cell models.    More...

 

EL-814 external view Sharp Model EL-814, S/N 3015931
Functions: ASMD, constant, 1 memory
Technology: MOS-LSI (2 chips), portable
Display: 8 digits, 7-segment LED modules
Dimensions: 90W x 150D x 32H
Weight: 0.43kg including batteries
Manufactured: Sharp, Japan, 1973.

The EL-814 from 1973 is a four-function calculator which uses a red light-emitting diode (LED) display. Red LEDs were first made in 1962, and were extremely expensive. The introduction of modular seven-segment displays in the early 1970s reduced the cost significantly, but the EL-814 would still have been a very expensive calculator.

The rectangular metal-trimmed case is normally covered by a plastic shutter. Sliding the shutter to the top of the case opens the keyboard, lifts a sun-shade over the display, and turns on the power. The calculator operates in the conventional algebraic manner to 8 significant figures, with a Constant function and a single memory register.

The EL-814 is very nicely built from six modules which simply clip or plug together. The circuitry is on two boards - the CPU board carries the Toshiba T3103 and T3105 processor chips, and the display board carries eight 7-segment LED modules and a T1271 driver chip. There is a custom LED module for polarity and memory indication, and two single LED indicators for Constant and Battery Low. Power consumption is rated at 600mW from 5 AA batteries. The batteries are held in a removable case which clips in place under the keyboard. A re-chargeable NiCad battery pack (EL-91) was available as an option.

EL-814 with cover closed (29kb)
EL-814 component modules (30kb)
EL-814 circuit boards (55kb)

 

EL-808 external view Sharp Model EL-808, S/N 4701443
Functions: ASMD
Technology: MOS-LSI (single chip), portable, LCD
Display: 8 digits, reflective liquid crystal
Dimensions: 110W x 180D x 40H
Weight: 0.45kg
Manufactured: Sharp, Japan, February 1974.

The EL-808 is a basic 4-function 8-digit calculator in a wedge-shaped casing with plastic trim panels. Its distinguishing feature is the use of a very early (and very expensive) reflective liquid-crystal display which produces bright silver numerals on a black background. The processor is an NEC uPD224C. The calculator draws 350mW from four AA batteries or an external 6V DC supply.    More...

 

EL-120 external view Sharp Model EL-120, S/N 41225563
Functions: ASMD, count
Technology: MOS-LSI (single chip), portable
Display: 3 digits, single fluorescent tube
Dimensions: 170W x 65D x 20H
Weight: 0.18kg
Manufactured: Sharp, Japan, February 1974.

The EL-120 is a compact portable calculator which uses an early multi-digit vacuum fluorescent display tube from Futaba in Japan. The tube has three multiplexed digits, a polarity sign, and two comma indicators mounted side-by-side in a glass tube about 65mm long. It is attached to the circuit board by flying leads from one end.

The calculator operates to 12 digits, which are displayed in groups of three (units, thousands, millions, etc). The operator can scroll the sections of the display with the yellow key, or have them scroll continuously by setting the A/M switch to A. The calculator has a white "Count" button on the lower edge which increments the integer display by one unit, and there is a 15cm ruler marked on the underside of the case.

The EL-120 has an elastomeric keyboard and a Hitachi HD3583 single-chip processor, with power supplied by three AA batteries.    More...

 

EL-122 external view Sharp Model EL-122, S/N 41193137
Functions: ASMD
Technology: MOS-LSI (single chip), portable
Display: 6/12 digits, single fluorescent tube
Dimensions: 88W x 143D x 42H
Weight: 0.28kg with batteries
Manufactured: Sharp, Japan, June 1974.

The EL-122 has a wedge-shaped case similar to the EL-816, but slightly smaller and with plastic trim panels on the sides. The calculator works to 12 digits on all operations, with the results displayed in two groups on a 6-digit fluorescent tube. The keyboard has a double-arrow key to select the upper or lower group, and a red LED indicator to show when the lower group is being displayed. The EL-122 uses a NEC μPD227C procesor, and draws 500mW from 3 AA batteries.
Internal view (29kb).

 

EL-8002 external view Sharp Model EL-8002, S/N 41228218
Functions: ASMD, percent
Technology: MOS-LSI (single chip)
Display: 8 digits, vacuum fluorescent display (single tube)
Dimensions: 88W x 143D x 42H
Weight: 0.27kg including batteries
Manufactured: Sharp, Japan, October 1974.

The EL-8002 is generally similar to the EL-122 above, but with 8-digit operation and an 8-digit display. The double-arrow key is no longer needed and has been replaced with a percent key. The display tube has 9 (smaller) digits, with one place reserved for polarity and error indication. The extra digits required a new double-ended construction to accommodate the extra connecting leads.

The rapid development of the multi-digit fluorescent tube greatly reduced the size and power requirements, leading to a portable 8-digit calculator drawing less than 300mW from three disposable AA batteries. The EL-8002 uses an elastomeric keyboard (similar to the EL-120), with a Hitachi HD3623 processor.
Circuit board and display tube (29kb).

 

EL-8011 external view Sharp Model EL-8011, S/N 58112120
Functions: ASMD, percent, square root
Technology: MOS-LSI (single chip)
Display: 8 digits, vacuum fluorescent display (single tube)
Dimensions: 80W x 135D x 25H
Weight: 0.23kg including batteries
Manufactured: Sharp, Korea, 1975.

The EL-8011 was built in Korea (rather than Japan) in 1975. It has a plain rectangular case, and is slim enough to be almost pocket-size. It has an elastomeric keyboard and a double-ended vacuum fluorescent display tube. The processor is a Hitachi HD36290, with power supplied from four disposable AA batteries.

 

EL-1101 external view 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 (above). In order to produce fluorescent displays of more than 8 digits the tubular construction had to be replaced with a new flat-panel design. The flying leads were replaced with a semi-rigid in-line connector strip which allowed many more connections and greatly simplified the assembly. The EL-1011 has an 11-digit display module, with one place reserved for polarity and error indication. 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 a Hitachi HD3683.    More...
Circuit board and display panel (27kb).

 

EL-8113S external view Sharp Model EL-8113S, S/N 61000844
Functions: Scientific, pocket/battery
Technology: MOS-LSI (single chip)
Display: 8 digits, vacuum fluorescent display
Dimensions: 80W x 135D x 30H
Weight: 0.23kg including batteries
Manufactured: Sharp, Japan, 1975.

The EL-8113S is a pocket-size calculator which includes "scientific" functions (logs, trig, and powers) but not "scientific" (ie exponential) notation. The floating-point display shows 8 digits with no round-off, and frequently displays errors in the scientific functions in the 7th or 8th place. The calculator uses a Hitachi HD3685 processor and a compact flat-panel fluorescent display module. It is powered from four disposable AA batteries, or an external AC adapter.

 

EL-501 external view Sharp Model EL-501, S/N 8600286Y
Functions: Scientific, pocket/battery
Technology: MOS-LSI (single chip)
Display: 8 digits, 2 exponent, vacuum fluorescent display
Dimensions: 80W x 140D x 30H
Weight: 0.23kg including batteries
Manufactured: Sharp, Japan, September 1977.

The Sharp EL-501 is a pocket-size scientific calculator that was cheap enough to be widely used by senior school students in the late 1970s. It uses a compact fluorescent display module with scientific notation, displaying "8+2" digits in less than 50mm width. The processor is from Hitachi (36128), and the power supply is from two AA batteries.

 

PC-1201 external view Sharp Model PC-1201, S/N 7400100Y
Functions: Scientific, programmable, pocket/battery
Technology: MOS-LSI (three chips)
Display: 10 digits, 2 exponent, vacuum fluorescent display
Dimensions: 80W x 150D x 20H
Weight: 0.21kg including batteries
Manufactured: Sharp, Japan, October 1977.

Sharp described the PC-1201 as a "Pocket Computer" rather than a "Programmable Calculator", although it is generally similar to other advanced calculators of the time.

The calculator provides a full range of scientific functions which are generally accurate to 9 places.

The programming capability provides 128 steps and includes labels, conditional branching, and one level of subroutine calls. Programs can be reviewed and edited from the keyboard, and are retained for up to a year by a separate memory backup battery. The calculator was supplied with a 260-page applications manual giving sample programs from mathematics, surveying, finance, and engineering.

The circuitry uses three LSI chips in 58-pin surface-mount flatpacks on a double-sided board, with a 14-digit Futaba display module. The calculator can be powered from two AA batteries, a special NiCad battery pack, and/or an external AC adaptor.    More...

 

Desk Calculators

CS-363 external view Sharp Model CS-363, S/N 11001705
Functions: ASMD, K, 3 memories
Technology: MOS-LSI (Rockwell, 6 chips)
Display: 16 digits, Nixie tubes
Dimensions: 295W x 335D x 100H
Weight: 3.9kg
Manufactured: Sharp, Japan, March 1971.

The Sharp CS-363 is a four-function desk calculator with a 16-digit Nixie-tube display and three memory registers. The blue keys at the right of the keyboard operate memory MI, while the black keys operate either MII or MIII depending on the setting of the adjacent slide switch. The reed-switch keyboard has provision for a third set of memory keys, which are not installed on this model. The switches at the left of the keyboard set the decimal places and roundoff modes for the display and memory separately. The processor uses a set of 6 Rockwell MOS-LSI chips (10061 to 10066) in 42-pin flat packs. The chips have date codes from November 1970 to February 1971, and the circuit boards are dated March 1971.

An extended version of the CS-363 with three rows of memory keys and a square root function was custom-built by Sharp for the Swedish Facit organisation. Please see the Facit 1135J page for further details.
CS-363 processor board (34kb)

 

EL-803 external view Sharp Model EL-803, S/N 3011182
Functions: ASMD, K key
Technology: MOS-LSI (single chip)
Display: 8 digits, vacuum fluorescent tubes
Dimensions: 180W x 190D x 75H
Weight: 1.5kg
Manufactured: Sharp, Japan, December 1972.

This Sharp EL-803 is a basic four-function desk calculator from 1972. The single-chip processor (Hitachi HD3276) requires four additional chips to drive the fluorescent display tubes.
Internal view (30kb)

 

EL-804 external view Sharp Model EL-804, S/N 3100707X
Functions: ASMD, K key
Technology: MOS-LSI (single chip)
Display: 8 digits, vacuum fluorescent tubes
Dimensions: 180W x 230D x 75H
Weight: 1.25kg
Manufactured: Sharp, Japan, July 1973.

The Sharp EL-804 from 1973 has the same functions and the same processor chip as the EL-803, but differs in the packaging and the display driver circuitry.

 

CS-2101 external view Sharp Model CS-2101, S/N 46209702
Functions: ASMD, K key, 1 memory
Technology: MOS-LSI (single chip)
Display: 12 digits, vacuum fluorescent tubes
Dimensions: 180W x 230D x 75H
Weight: 1.22kg
Manufactured: Sharp, Japan, November 1973.

This CS-2101 from late 1973 is a more elaborate four-function desk calculator with a 12-digit flat-panel display. It has a single memory register accessed through the blue keys on the right-hand side. The modular keyboard assembly has an un-used position where we would now expect to find the "M-" key. Although the procesor chip is branded "Sharp", the part number (15352) and the staggered-pin packaging suggest that it was actually made by Rockwell.
Circuit board detail (28kb)

 

PC-1001 external view Sharp Model PC-1001, S/N 31048812
Functions: Scientific, programmable
Technology: MOS-LSI (5 chips), mains power
Display: 10 digits, 2 exponent, vacuum fluorescent tubes
Dimensions: 140W x 225D x 70H
Weight: 1.06kg
Manufactured: Sharp, Japan, November 1973.

The PC-1001 from 1973 is a programmable scientific calculator in a compact desktop case. It provides scientific notation, trig and log functions, 8 directly-accessible memory registers, and is programmable from the keyboard. The circuitry is built from a general-purpose 4-bit microprocessor system (the Rockwell PPS-4) rather than a dedicated calculator chipset.
More...

 

PC-1002 external view Sharp Model PC-1002, S/N 41006506
Functions: Scientific, programmable
Technology: MOS-LSI (6 chips), mains power
Display: 10 digits, 2 exponent, vacuum fluorescent tubes
Dimensions: 140W x 225D x 80H
Weight: 1.17kg
Manufactured: Sharp, Japan, 1974.

The PC-1002 from 1974 is an expanded version of the PC-1001 above. It provides additional scientific functions and basic statistics (mean and standard deviation), and includes a user-accessible IC socket for optional pre-programmed ROM modules.
More...

 

Printing Calculators

Sharp CS-743R external view Sharp CS-743R Printing Calculator, S/N 31490607
Functions: ASMD, K, percent, 2 memories
Technology: MOS-LSI (4 chips)
Display: 18-column impact printer
Dimensions: 260W x 320D x 110H
Weight: 5.6kg
Manufactured: Sharp, Japan, 1973.

Sharp's CS-743R from 1973 uses a Shinshu Seiki (later renamed to Epson) EP-102 modular impact printer to record all entries, operations, and results on a 57mm paper tape. The calculator has no separate numerical display - but then, neither did most of the mechanical adding machines that it was designed to replace.

Addition and subtraction operate in the traditional adding-machine fashion with total and sub-total keys, while multiplication and division operate algebraically. There are two independent memory registers which are accessed via the blue and black keys on the right-hand side. The memory controls are also labelled with total and sub-total, rather than the now-familiar "recall" and "clear" functions. There are two indicator lamps to show when the memories are active. The keyboard mechanism is built in several sections, using glass reed switches operated by magnets on the ends of the key stems.

The calculator circuitry uses four main LSI chips in 24-pin ceramic packages, 15 smaller chips in 14 and 16-pin packages, over 40 discrete transistors, and a host of individual components. The IC chips are all from NEC.
Internal view (38kb)

 

Sharp CS-523 external view Sharp Compet CS-523R Printing Calculator, S/N 49029203
Functions: ASMD, K, percent
Technology: MOS-LSI (2 chips)
Display: 15-column impact printer
Dimensions: 250W x 320D x 110H
Weight: 4.5kg
Manufactured: Sharp, Japan, 1974.

The CS-523 is a smaller and simpler print-only calculator from early 1974. The processor uses two NEC chips (μPD221 and 222) in 28-pin packages, with only one support chip. The case has mountings for the EP-102 printer, but is fitted with a smaller 15-column EP-104 mounted on elevated brackets. The keyboard uses separate key switches which are individually screwed to a metal baseplate. Operation is the same as for the CS-743 above, apart from the lack of memory keys.

The CS-523 circuit board is drilled and labelled for 4 additional 16-pin chips, and has mountings on the keyboard for 4 additional keys, so there is presumably another model which includes the memory functions. The Facit Model 1148 (built made by Sharp for the Swedish Facit company) uses the same chipset with the additional components installed.
Internal view (29kb)

 

Resources for further information


Original text and images Copyright © John Wolff 2003-13.
Use at own risk; beware of errors; suggestions for improvement welcome.
Last Updated: 4 February 2013

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