Hand-held Calculators

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Sharp PC-1210 & Sharp PC-1211
(Radio Shack/Tandy TRS80 PC-1)

The Sharp PC-1211 and Sharp PC-1210 Pocket Computers, introduced in 1980, are included here to show the culmination of ten years of development of the hand-held calculator. Although by this time there were many programmable pocket calculators, starting with the Hewlett-Packard HP-65 of 1974, these can legitimately be described as a pocket computers since, unlike the programmable calculators, they have a full "QWERTY" keyboard and are programmed in the high-level BASIC computer language.

The Sharp PC-1211 (also sold by Radio Shack/Tandy as the TRS80 PC-1) and Sharp PC-1210 are similar though differ in the amount of program memory.

Sharp PC-1211 Pocket Computer
(also sold as the Radio Shack/Tandy TRS80 PC-1)

Sharp PC-1211/TRS80 PC-1

Sharp PC-1211 Pocket Computer, also sold as the RadioShack/Tandy TRS80 PC-1

Distinctive features: First hand-held pocket computer, programmable in the BASIC language.

Technical details:
Display
- 24-digit alphanumeric dot matrix Liquid Crystal Display, with yellow filter.
In calculator mode it can display in scientific format 10 digits mantissa and 2 digits exponent.

Functions - Calculator and 1424 step BASIC language programmable computer.
26 Fixed memories.
Up to 178 Flexible memories (shared with program memory).
Battery back-up of CMOS memory.
A cassette recorder can be connected using an adapter cradle, allowing programs to be saved to audio cassettes. Also a printer & and cassette adapter was available, see photograph below, thus providing the full needs of a pocket computer.

Power supply - 4x Mercury button cells, giving "approx. 300 hours" use. The power consumption is 0.011 watts.

Semiconductors - CMOS LSI, including:

Size 175 x 70 x 17 mm (6.9" x 2.75" x 0.7").

Introduced - 1980[1].

Made in Japan.

Board 1

With the rear cover removed showing the "operation" pcb. CPU 2 is the chip in the centre of the board.

Board 2

The "operation" pcb has been hinged downwards to show components on its rear, including the three RAM memory chips on the left.
The "keyboard & display" pcb is revealed, which  has the CPU 1 chip on its left, and three display chips (with built-in RAM) from top-centre to right.

The PC1211attached to the CE-121Cassette Interface unit, which allows programs to be stored on audio cassette tapes and recalled later.
The red plug goes to the cassette recorder "Mic" socket, the grey plug goes to the "Earphone" socket, and the black plug goes to the "Remote" socket.

The PC1211 attached to the CE-122 Printer & Cassette Interface unit and sitting in the de luxe carrying case.

Sharp PC-1210 Pocket Computer

Sharp PC-1210

Sharp PC-1210 Pocket Computer

Distinctive features: First hand-held pocket computer, programmable in the BASIC language.

Technical details:
Display
- 24-digit alphanumeric dot matrix Liquid Crystal Display, with yellow filter.
In calculator mode it can display in scientific format 10 digits mantissa and 2 digits exponent.

Functions - Calculator and 400 step BASIC language programmable computer.
Up to 50 Flexible memories (shared with program memory).
Battery back-up of CMOS memory.
A cassette recorder can be connected using an adapter cradle, allowing programs to be saved to audio cassettes. Also a printer & and cassette adapter was available, see photograph below, thus providing the full needs of a pocket computer.

Power supply - 3x Silver oxide button cells. The power consumption is 0.009 watts.

Semiconductors - CMOS LSI, including:

Size 175 x 70 x 17 mm (6.9" x 2.75" x 0.7").

Introduced - 1980[1].

Made in Japan.

Board 1

With the rear cover removed showing the "operation" pcb. CPU 2 is the chip in the centre of the board.

Board 2

The "operation" pcb has been hinged downwards to show components on its rear, with only a single RAM memory chip on the left, compared with the three RAM memory chips in the PC-1211, at the top of the page.
The "keyboard & display" pcb is revealed, which  has the CPU 1 chip on its left, and three display chips (with built-in RAM) from top-centre to right.

There is information about Sharp pocket computers at http://sharppocketcomputers.com/, including downloadable pdf sales brochure for the PC-1211 and a very interesting Service Manual for it.

Ten Years of Calculator Progress

Sharp were one of the pioneers in hand-held calculators in 1970 with the EL-8 and were very successful in the calculator business through the turbulent years of the 1970s. Ten years on from the EL-8 they were still at the forefront of technology with this, one of the first pocket computers.

For comparison, there are details of the EL-8 below.

Sharp PC-1211/TRS80 PC-1

The Sharp PC-1211 pocket computer of 1980, in its Radio Shack / Tandy TRS-80 guise.

Sharp EL-8

Comparison with the Sharp EL-8 hand-held calculator of 1970/1.

Functions:

  • EL-8 - 4 function.
  • PC-1211 - 1424-step BASIC language programmable.

Batteries:

  • EL-8 - 6x AA rechargeable Ni-Cad cells giving 3 hours use.
  • PC-1211 - 4x Mercury button cells giving 300 hours use.

Cost:

  • EL-8 $345 (about 145 Sterling).
  • PC-1211 $229 (about 102 Sterling) (Tandy TRS-80 PC-1 introductory price).
Sharp EL-8

Sharp EL-8 with the back removed showing the rechargeable battery pack containing 6x AA NiCad cells.

Sharp EL-8 board

The display board of the Sharp EL-8 with the vacuum fluorescent display tubes and the display driver chips.

Sharp EL-8 board

The calculating circuit board of the Sharp EL-8 with the 5 chips then required to give the standard 4 functions.

Reference

  1. White, M., "How I use my pocket computer", Popular Science, Nov. 1980, p105.

Hand-held Calculators

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© Text & photographs copyright Nigel Tout   2000-2017  except where noted otherwise.