== One Per Desk OPD Computer << Sinclair QL Clone >>===

One Per Desk Computer with Monitor (Sinclair QL Clone)

The OPD (One Per Desk) computer was manufactured by ICL who badge engineered it as the MERLIN TONTO for BT and as the COMPUTERPHONE for Telcom. Australia (APT). The 3 models were released in late 1984/early 1985.  The computer resulted from collaborative development by ICL, Sinclair and BT, with PSION providing the XCHANGE programs. The hardware skeleton is based on the Sinclair QL. This includes the 68008 CPU, the two main QL ULAs (Uncommitted Logic Arrays), the method of dynamic RAM (DRAM) and screen management, the real time clock and the microdrives.

Many were sold to local authorities, government departments, but the OPD seems to be very rare nowadays - I understand that not even its makers, ICL, have one in their archive.

As you can see it is working, I haven't any microdrive carts so I cannot test the microdrives but they do operate when you try to load something but obviously a 'file not found' or similar error occurs.

All the photographs here are my photos of the actual computer.

Because it is very heavy I would pefer the winner to collect in person. Although I will also send it by Parcel Force or via the Post Office. 

Main Features:-

• Motorola 68008P8 CPU (7.5 Mhz)
• 128k RAM
• Modem
• 2 x Telephone Conections
• Speech Synthesiser
• 2 x Microdrives
• Real Time Clock
• 14" Microvitec Colour Monitor
• Graphics 512x256 (4 colours), 256x256 (8 colours)

HARWARE SUMMARY
CPU
The main processor is a Motorola 68008P8, 8X16 bit device with a 7.5 Mhz clock and a 1 Mbyte memory address capability. A second processsor, an 8051 in the modem, controls the keyboard and the communications functions

RAM
128k DRAM (2 banks of 64K K 8 bit, using 4164-15 ICs)
2K Battery backed CMOS RAM. (The PERMANENT STORE: a TC5516AP-2 IC).
32k of RAM is allocated to the screen. This, plus standard demands, leaves approximately 75k of work space [ 150 blocks of 512 bytes ].
128K is reserved for expansion RAM. (To allow a total of 256k of DRAM).

ROM, INTERNAL
128k of Operating System (OS) (4 off 32K x 8 bit ROMs) (16K of Speech synthesiser ROM is controlled directly by the speech synthesizer IC and is outwith the 68008's memory map).
64K is reserved for expansion of the Operating System.

MODEM
The modem is a plug-in, BT approved (and designed), dual line, auto-dial/auto-answer unit based on the ADM7910 IC. The following facilities are provided:-

1200 bps half duplex, (Bell 202, CCITT V23 mode 2)
600 bps half duplex, (CCITT V23 mode 1)
75/1200 bps full duplex, (Viewdata)
300 bps full duplex, (Bell 103, CCITT V21)

TELEPHONE

The telephone handset is a standard BT 'Sceptre' type. There is an 8 ohm 250mW moving coil loudspeaker in the control unit but no in-built microphone. Facilities include 'hands-free' call initiation, loudspeaker call monitoring, auto-dial from memory or manual dial from the keyboard and store plus re-call/re-dial of the last 6 numbers used. The directory is capable of holding 500+ entries but at this level there is little memory left for other functions. The telephone directory has 'browse-and-search' facilities plus short code dialling. A single screen priority directory can be displayed by the LIST key and there is a facility to record the cost of calls.

The basic telephone functions for manual dialling are battery backed, allowing one line to make and receive voice calls if mains power is lost.

SPEECH SYNTHESISER
This consists of a Texas TMP5220C IC with a vocabulary in a separate, custom ROM of 152 words, plus letters and numbers. Facilities include limited text-to-voice conversion from keyboard entry and playback-to-test. Up to 16 messages can be pre-assembled and 2 used, automatically, by time-of-day selection, for auto-answer of incoming voice calls. Incoming voice messages cannot be recorded.

MICRODRIVES
There are 2 microdrives each of 100K nominal capacity (95K minimum). They are not identical to the QL drives in mechanical construction, or operational protocol, but the blank microdrive cartridges can be used on either machine. An adjustable 'end-of-life' warning is provided for tape data quality/total number of seconds used.

[ The OPD micro drives have greater data packing density than the QL but more space between data blocks resulting in comparable overall capacity. Certain metal components are replaced with plastic and the amount of lubrication on the tape has been changed ]

REAL TIME CLOCK
The clock is the same as the QL except that the start date is l/l/1970 while the QL start date is l/l/1961. The clock output is displayed in the Notice Board at the bottom of the screen.

VDU (Monitor)
The OPD control unit is designed to be permanently powered and to blank the VDU screen if the keyboard is not used for 10 minutes. Operating any key recovers the display. The ON/OFF switch removes full voltage from the monitor, but maintains a reduced supply to prewarm the tube heater for fast start-up This switch does not affect supplies to the control unit The intent was that the monitor should be switched OFF between sessions but the control unit should remain powered for MESSAGING and other, unattended, functions.

SCREEN FORMAT
The screen format is similar to the QL. It is bit mapped and has 2 modes selectable from software:-

256x256 pixels, 40 characters per line, 24 lines plus a 2 line 'Notice Board' at the bottom of the screen. Green, red and blue can be displayed on a colour monitor, giving 8 shades (contrast levelled plus flashing, on a monochrome monitor.

512x256 pixels, 40 or 80 characters per line, 24 lines plus a 2 line 'Notice Board'. Red and green only are available on a colour monitor giving 4 shades on a monochrome monitor.

In BASIC the screen size available as display for the running program is less than the gross figures quoted above e.g. in the 512x256 mode the BASIC program display area is only 480x200.

PRINTER INTERFACE
This is a single RS423 serial port which is compatible with RS232 for printer duty. The port consists of a 9 way female D connector on the OPD control unit (only 3 pins of the connector are used).
The ICL package printer was an OKI thermal, colour printer with a draft printing speed of 80 cps and 40 cps in NLQ.

BATTERIES
The OPD has 2 batteries: BAT1 is a 9 volt, PP3, manganese battery which backs the telephone and the Real Time Clock. It is fitted under the microdrive cover and is user replaceable. The Operating System checks BAT1 voltage during power-up and under the HOUSEKEEPING function. BAT2 is a 3 volt lithium unit (with a life of at least 5 years) which backs the PERMANENT STORE CMOS RAM. It is soldered to the motherboard; is not considered user replaceable and is not checked directly by the Operating System.

KEYBOARD
The 73 key keyboard is QWERTY layout with 10 of the keys colour coded to act as function keys and double as a 'telephone style' numeric pad. The keyboard is manufactured by ALPS using individual switches of rubber membrane construction.

OPERATING SYSTEM (OS)
The OS is an ICL multi-tasking 'special'. up to 5 tasks can be run concurrently. It is not QL QDOS nor is it an industry standard which can take advantage of existing software. The OS is contained in 4 X 32K ROMs on the CPU board. A further 14K is carried in the ROMPACK. ICL called the OS 'BFS' (Basic Functional Software) ZX80 ZX81  Spectrum

 

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On 13-Nov-05 at 04:42:48 GMT, seller added the following information:

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