ICL One Per Desk / BT Merlin Tonto
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OPD Related News
OPD BASIC compiler and interpreter found
A long lost BASIC compiler and BASIC interpreter have recently been discovered for the ICL One Per Desk.
These software tools will make it easier to develop new applications for the OPD and to port SuperBASIC programs from the QL to the OPD. Both programs can be loaded from microdrive cartridge or Teledrive disc or 'burned' onto eproms and fitted into modified ROM packs or ROM capsules.
We are in the process of OCR-ing the C1 compiler manual and related documentation.
C1 BASIC Compiler
The Computer One BASIC compiler (C1 BASIC) takes an interpreted SuperBASIC program and compiles it into a machine code program. The C1 compiler library carries a small overhead of approximately twenty kilobytes or forty blocks of OPD store. Compiler SuperBASIC programs run significantly faster and there is no need to run a seperate BASIC compiler from cartridge or capsule.
The user is presented with six options from the main menu : compiler, editor, assembler, monitor, spooler and linker.
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The program editor allows one to edit source code prior to compilation. It was fairly straightforward to compile programs written in ICL BASIC. We have had some success porting simple SuperBASIC programs from the QL to the OPD, though it is advisable to run the BASIC source code through Dave Walkers' OPD/QL Interchange tools.
MetaComco BASIC Interpreter
MetaComco developed a number of well renowned compilers for the QL and Atari ST.
The OPD MetaComco BASIC interpreter was delivered in December 1986 and according to the documentation is compatible with Microsoft BASIC. MetaComco appears to be faster and more efficient than ICL Basic, using less than thirty kilobytes of working memory which equates to sixty blocks of store. The interpreter occupies four memory slots so may be fitted as a four ROM capsules or the same number of eprom chips can be added to a spare OPD ROM pack.
If one is fortunate enough to have a PCML Telestore memory expansion unit and PCML Telestore disc unit, one can load the BASIC interpreter from disc or RAM disc.
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Compiler and Interpreter ROM images
ROM images for the Computer One BASIC compiler and MetaComco BASIC interpreter will be made available in the QUANTA members area in due course. We hope to publish sample SuperBASIC programs which you can use to test the compiler and interpreter, as well as providing step by step instructions for buring ROM images to eproms and fitting them into OPD ROM packs.
It is surprisingly easy to burn eproms on a PC equipped with a parallel or USB programmer or a Sinclair QL equipped with a QEP III programmer.
The OPD memory map is divided into 32K slots. If you intend to run these applications in ROM, you will need four 27C256 eproms for the MC BASIC interpreter (4 x 32K = 128K) and two 27C256 eproms (2 x 32K = 64K) for the C1 compiler.
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OPD ServPack discovered
We have recently come across an unusual diagnostic tool called ServPack which will aid troubleshooting hardware faults on OPDs.
ServPack was most probably used by ICL test engineers to diagnose OPD faults and to carry out soak tests on the production line. ServPack is a custom designed ROM pack and PAL logic chip which checks each of the OPD's sub systems : dynamic and static memory, the monitor, keyboard, telephone unit, voice synthesiser, microdrive units and popular expansion units. Paged capsules enable to OPD to overcome the 1Mb memory barrier and access devices such as RAM discs.
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 The ServPack program fits on two eproms and may be fitted and is seen fitted to a standard two slot ROM pack. The PAL chip has yet to be decoded! |
MegaOPD unearthed
ICL produced a small number of enhanced OPD's for the American market.
We have recently unearthed a small number of these facinating machines which give an insight into how the OPD may have evolved if it had been more commercially successful.
'MegaOPDs' have larger on board store (256K rather than 128K), the ability to adress up to 4Mb of memory, and enhanced ICL operating system, upgraded modem and a 68000 processor.
The circuit board contains a number of surface mounted chips not seen on the standard OPD.
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