One Per Desk
Encyclopedia
The One Per Desk, or OPD, was an innovative hybrid personal computer
/telecommunications terminal based on the hardware of the Sinclair QL
. The One Per Desk was built by International Computers Limited (ICL) and launched in the UK
in 1984. It was the result of a collaborative project between ICL, Sinclair Research and British Telecom begun in 1981, originally intended to incorporate Sinclair's flat-screen CRT
technology.
Rebadged versions of the OPD were sold in the United Kingdom
as the Merlin Tonto and in Australia
as the Telecom Australia Computerphone.
CPU, ZX8301
/8302
ULAs, 128 KB of RAM and dual Microdrives
(re-engineered by ICL for greater reliability) but not the 8049 Intelligent Peripheral Controller. Unique to the OPD was a "telephony module" incorporating an Intel 8051
microcontroller
(which also controlled the keyboard), two PSTN lines and a V.21/V.23 modem
, plus a built-in telephone handset and a TI
TMS5220
speech synthesiser (for automatic answering of incoming calls).
The OPD was supplied with either a 9-inch monochrome (white) monitor or a 14-inch colour monitor. Both monitors also housed the power supply for the OPD itself.
Later, 3.5" floppy disk drives were also available from third-party vendors.
operating system, although a subset of SuperBASIC
was provided on Microdrive cartridge. The BFS provided application-switching, voice/data call management, call answering, phone number directories, viewdata
terminal emulation and a simple calculator.
The Psion applications suite bundled with the QL was also ported to the OPD as Xchange and was available as an optional ROM
pack.
Other optional application software available on ROM included various terminal emulators such as Satellite Computing's ICL7561 emulator, plus their Action Diary and Presentation Software, address book, and inter-OPD communications utilities.
An ICL supplied application was used to synchronise a national bingo game across hundreds of bingo halls in the UK. The integral V.23 dialup modem was used to provide remote communications to the central server.
Several UK ICL Mainframe (Series 39
) customers, in Local Government and Ministry of Defence sectors, used statistics applications on OPD systems to view graphical representations of mainframe reports. Once again, the integral V.23 modem was used to download from the mainframe.
s and other similar systems through the BT telephone network. It is said that the power supply unit was unreliable and often failed on most units. The Tonto retailed at £1,500 at launch. OPD peripherals and software ROM cartridges were also badged under the Merlin brand. BT withdrew support for the Tonto in February 1993.
The name Tonto was derived from "The Outstanding New Telecoms Opportunity" .
port and enhanced firmware.
Personal computer
A personal computer is any general-purpose computer whose size, capabilities, and original sales price make it useful for individuals, and which is intended to be operated directly by an end-user with no intervening computer operator...
/telecommunications terminal based on the hardware of the Sinclair QL
Sinclair QL
The Sinclair QL , was a personal computer launched by Sinclair Research in 1984, as the successor to the Sinclair ZX Spectrum...
. The One Per Desk was built by International Computers Limited (ICL) and launched in the UK
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
in 1984. It was the result of a collaborative project between ICL, Sinclair Research and British Telecom begun in 1981, originally intended to incorporate Sinclair's flat-screen CRT
Cathode ray tube
The cathode ray tube is a vacuum tube containing an electron gun and a fluorescent screen used to view images. It has a means to accelerate and deflect the electron beam onto the fluorescent screen to create the images. The image may represent electrical waveforms , pictures , radar targets and...
technology.
Rebadged versions of the OPD were sold in the United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
as the Merlin Tonto and in Australia
Australia
Australia , officially the Commonwealth of Australia, is a country in the Southern Hemisphere comprising the mainland of the Australian continent, the island of Tasmania, and numerous smaller islands in the Indian and Pacific Oceans. It is the world's sixth-largest country by total area...
as the Telecom Australia Computerphone.
Hardware
From the QL, the OPD borrowed the 68008Motorola 68008
The Motorola 68008 is an 8/16/32-bit microprocessor made by Motorola. It is a version of the Motorola 68000 with an 8-bit external data bus, as well as a smaller address bus.The original 68000 had a 24-bit address bus and a 16-bit data bus...
CPU, ZX8301
ZX8301
The ZX8301 was a ULA integrated circuit designed for the Sinclair QL microcomputer. Also known as the "Master Chip", it provided a Video Display Generator, the division of a 15 MHz crystal to provide the 7.5 MHz system clock, ZX8302 register address decoder, DRAM refresh and bus controller...
/8302
ZX8302
The ZX8302 was a ULA integrated circuit designed for the Sinclair QL microcomputer. Also known as the QL's "Peripheral Chip", it interfaced the CPU to the Microdrives, QLAN local area network interface and RS-232 ports and also provided a real-time clock. The ZX8302 was IC23 on the QL motherboard....
ULAs, 128 KB of RAM and dual Microdrives
ZX Microdrive
The ZX Microdrive is a magnetic tape data storage system launched in July 1983 by Sinclair Research for their ZX Spectrum home computer. The Microdrive technology was later also used in the Sinclair QL and ICL One Per Desk personal computers.-Development:...
(re-engineered by ICL for greater reliability) but not the 8049 Intelligent Peripheral Controller. Unique to the OPD was a "telephony module" incorporating an Intel 8051
Intel 8051
The Intel MCS-51 is a Harvard architecture, single chip microcontroller series which was developed by Intel in 1980 for use in embedded systems. Intel's original versions were popular in the 1980s and early 1990s. While Intel no longer manufactures the MCS-51, binary compatible derivatives remain...
microcontroller
Microcontroller
A microcontroller is a small computer on a single integrated circuit containing a processor core, memory, and programmable input/output peripherals. Program memory in the form of NOR flash or OTP ROM is also often included on chip, as well as a typically small amount of RAM...
(which also controlled the keyboard), two PSTN lines and a V.21/V.23 modem
Modem
A modem is a device that modulates an analog carrier signal to encode digital information, and also demodulates such a carrier signal to decode the transmitted information. The goal is to produce a signal that can be transmitted easily and decoded to reproduce the original digital data...
, plus a built-in telephone handset and a TI
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
TMS5220
TMS5220
The Texas Instruments LPC Speech Chips are a series of speech synthesizer DSP ICs created by Texas Instruments beginning in 1978. They continued to be developed and marketed for many years, though the speech department moved around several times within TI, until finally the speech department...
speech synthesiser (for automatic answering of incoming calls).
The OPD was supplied with either a 9-inch monochrome (white) monitor or a 14-inch colour monitor. Both monitors also housed the power supply for the OPD itself.
Later, 3.5" floppy disk drives were also available from third-party vendors.
Software
The system firmware (BFS or "Basic Functional Software") was unrelated to the QL's QdosSinclair QDOS
QDOS is the multitasking operating system found on the Sinclair QL personal computer and its clones...
operating system, although a subset of SuperBASIC
SuperBASIC
SuperBASIC was an advanced variant of the BASIC programming language with many structured programming additions. It was developed at Sinclair Research by Jan Jones during the early 1980s. Originally SuperBASIC was intended for a home computer, code-named SuperSpectrum, then under development...
was provided on Microdrive cartridge. The BFS provided application-switching, voice/data call management, call answering, phone number directories, viewdata
Viewdata
Viewdata is a Videotex implementation. It is a type of information retrieval service in which a subscriber can access a remote database via a common carrier channel, request data and receive requested data on a video display over a separate channel. Samuel Fedida was credited as inventor of the...
terminal emulation and a simple calculator.
The Psion applications suite bundled with the QL was also ported to the OPD as Xchange and was available as an optional ROM
Read-only memory
Read-only memory is a class of storage medium used in computers and other electronic devices. Data stored in ROM cannot be modified, or can be modified only slowly or with difficulty, so it is mainly used to distribute firmware .In its strictest sense, ROM refers only...
pack.
Other optional application software available on ROM included various terminal emulators such as Satellite Computing's ICL7561 emulator, plus their Action Diary and Presentation Software, address book, and inter-OPD communications utilities.
An ICL supplied application was used to synchronise a national bingo game across hundreds of bingo halls in the UK. The integral V.23 dialup modem was used to provide remote communications to the central server.
Several UK ICL Mainframe (Series 39
ICL Series 39
The ICL Series 39 was a range of mainframe and minicomputer computer systems released by the UK manufacturer ICL in 1985.- Origins :The Series 39 range was based upon the New Range concept and the VME operating system from the company's ICL 2900 line, and was introduced as two ranges:* Series 39...
) customers, in Local Government and Ministry of Defence sectors, used statistics applications on OPD systems to view graphical representations of mainframe reports. Once again, the integral V.23 modem was used to download from the mainframe.
Merlin Tonto
British Telecom Business Systems sold the OPD as the Merlin M1800 Tonto. BT intended the Tonto to be a centralised desktop information system able to access online services, mainframeMainframe computer
Mainframes are powerful computers used primarily by corporate and governmental organizations for critical applications, bulk data processing such as census, industry and consumer statistics, enterprise resource planning, and financial transaction processing.The term originally referred to the...
s and other similar systems through the BT telephone network. It is said that the power supply unit was unreliable and often failed on most units. The Tonto retailed at £1,500 at launch. OPD peripherals and software ROM cartridges were also badged under the Merlin brand. BT withdrew support for the Tonto in February 1993.
The name Tonto was derived from "The Outstanding New Telecoms Opportunity" .
MegaOPD
An enhanced version of the OPD was produced in small numbers for the US market. This had a 68008FN CPU, 256 KB of RAM as standard, an RS-232RS-232
In telecommunications, RS-232 is the traditional name for a series of standards for serial binary single-ended data and control signals connecting between a DTE and a DCE . It is commonly used in computer serial ports...
port and enhanced firmware.