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S > SINCLAIR  > QL (Quantum Leap)

QL (Quantum Leap)

Sinclair QL

The  price of the QL compared with other popular computersThe Sinclair QL was the first attempt for Clive Sinclair to produce a computer for business. But after the success of the ZX-81 and ZX Spectrum, the QL can also be regarded as the first failure of Sinclair. In January 1984, Clive Sinclair presents the QL to the press, unveiling a very promising and inventive machine, based on the 68008 processor from Motorola. Indeed it was the first home computer based on a 32 bits CPU, just a few days before the Apple Macintosh. It was important for Clive Sinclair to unveil the QL before the Macintosh, but that was also one of the main reasons for the QL's failure...



In 1982, Tony Tebby, a young but experimented engineer, enters Sinclair Research as the head of the ZX-83 project. Clive's words were "I want an Unix-like mono-user multi-tasks operating system which will fit into 32k RAM with its Basic". From there, Tony worked hard on his version of the OS, while he also asked GST, a Cambridge company, to develop their own solution. Seven months later, his solution was chosen by Clive Sinclair.

The result is the QDOS (for QL Disk Operating System), a very clever and innovative multi-tasking and pre-emptive operating system. Tony Tebby wrote it entirely in machine code. This excellent OS is the main reason for the passion around the QL until nowadays. Among other things the way it handles system tasks was revolutionary. Even Linus Torvalds admitted that he learned multi-tasking on his QL, before he conceived Linux !

Some OS were derived from the QDOS to equip modern "re-incarnations" of the QL, the most spread being SMSQ and SMSQ/E developped by Tony Tebby himself ! Yes, Tony, is still very active on the QL stage and is even developing a brand new OS, Stella, which will be the result of all his innovative ideas !

At the time of the announcement, the Quantum Leap (code named "ZX-83") was not yet ready. But Sinclair started the sales and promised a QL in April for those who sent a cheque to Sinclair now. The problems started here... Sinclair took the money without sending the computers, mainly to earn the interests from it some said...

The KlutgeThe fact is that the press and the public were unhappy with the QL affair. From then it was a race for the Sinclair engineers to finish the QL as quickly as possible. The main hesitation was about the Super Basic. It was developed by a woman (!), Jan Jones, as an evolution of the Sinclair Basic of the Spectrum. It was meant to equip the Loki, a "super Spectrum" that was planned by Sinclair. Finally, the Super Basic was included into the QL. But they didn't know if it was better to deliver the Super Basic on Microdrives tapes or burnt into ROMs.

At that stage, the first Microdrives were not very reliable, so it was decided the Super Basic would be in ROM. But the QL was designed to have 32k ROM and the QDOS + Super Basic would fit only in 48k ! That's why the first QLs sold were delivered with an external ROM cartridge with another 16Kb ROM. This was called the "dongle". Later models had the extra ROM built inside the machine, it was piggybacked on top of one of the two other ROMs and after that, they used one 32Kb and one 16Kb ROM.



The first models tested by the English press were disastrous. Most of them hanged whenever they wanted, resulting in a data loss and reset of the machine !

The two first ROM versions (FB and PM) were buggy and retired from the sales. In June 84 the first " acceptable " ROM was available (AH) and was soon replaced by a stable one (JM).

Early in 1985, arrives the JS ROM, which will be the last version used in machines made for sale in Britain. It was the first version which was able to link more than one plug-in device to the QL !

MGx are European ROMs, the third character indicating the national variant of the ROM (MGE : Spanish, MGF : French, MGG : German, MGI : Italian, MGS : Swedish)



The QL was supplied complete with a suite put together by PSION consisting of a fully functional word processor (Quill), spreadsheet (Abacus), database (Archive) and a business graphics programs (Easel).

The PSION software

These applications were very powerful and were later developed for PCs. But the first versions were too big and didn't fit in RAM, so they used the Microdrives a lot, nearly for each different command ! The first criticisms of the Microdrives were in fact caused by the way the Psion software worked.

Later, the Psion applications were rewritten from C to machine code, thus being faster and smaller, each application fitting entirely into the memory, no more need to load each part from the microdrives.



The microdrives are original small mass-storage device developed by Sinclair. They use tiny cartridges with endless magnetic tapes. Each cartridge can store about 100k. This is not fantastic, but it was a good and cheap alternative to far more expensive disk-drives. In fact the QL would have cost much much more if there were disk drives instead of Microdrives (the keyboard was also a reason for the low price).

The microdrives are basically the same as the ZX Spectrum ones, but the format of the tapes is a bit different. Otherwise you can use the same cartridge as long as you format it for the right machine (QL or Spectrum).

The Microdrives were thus slower than disk drives but much faster than normal "audio" tapes. Personally, I think they don't deserve all the criticisms made against them. ICL proved with their OPD computer (derived from the QL), that the microdrives could be quite reliable. Indeed, the ICL engineers enhanced the Sinclair Microdrives for the OPD...

As relatively fragile magnetic devices, some Microdrive tapes tend to be unusable nowadays. But so it is with old disks or tapes too...

For those of you who have a QL but no documentation and wonder how to use the microdrives, here are basic commands :

DIR MDV1_ displays the directory of the microdrive 1
LRUN MDV2_programname runs the program called "programname" on the microdrive 2

Hope that helps...


The design is excellent ! All black with pure angular shapes and an innovative keyboard. It is not a real full-stroke keyboard but the sensation is ok, though not fantastic...

The QL is delivered with many connectors. There are 2 network sockets. They were for Sinclair's `QLAN' network, which can connect Sinclair QLs and Sinclair ZX-Spectrums at 100k baud, but this feature was almost never used...

There are also 2 controller sockets, Sinclair type, which make it hard nowadays to plug a mouse or a joystick to a QL.

The ROM connector was also under-used. Maybe its only use was with the extra ROM of the early QLs !

For the video output you have the choice between a RF TV output and a RGB video output (DIN plug). If you have lost your RGB cable, you can use the Spectrum +2 or +3 ones, they are the same !

On the right side, there is a connector for two extra microdrives, which was surely never used, as very quickly several disk drives were developed by third-party companies. The micro-drives were definately not the recommended mass-storage device to use with the QL....

Finally, on the left, a bus extension port for RAM extensions and floppy drives was available. This was the most used connector of the QL. But most expansions had to offer the same port on their other side, otherwise you could only plug one extension into your QL !



As I just said, diskdrives interfaces quickly appeared for the QL, as the built-in microdrives were not sufficient for professional use of the QL. Many other cards were produced, some with very powerful features.

The Gold Card, for example, made by Miracle systems, offered a 16 MHz 68000 CPU, 2 Mb of RAM and a DD/HD/ED floppy I/F interface ! The Super Gold Card had the same features but added a 24 MHz 68020 CPU, 4 Mb of RAM and a parallel port.

TF Services conceived and still sells the Super HERMES card which mainly offers a new co-processor replacement for the buggy 8049. This card is based on the RISC PIC17C44 processor and cures all the 8049 bugs while adding many new features: high-speed serial interface (up to 19200 bps on ser1 and ser2, up to 115200 bps on the new ser3 with DCD, DSR and DTR support), IBM keyboard interface, serial mouse interface, plus many other small goodies ! Impressive...

The Aurora card made by QubbeSoft is a graphics card which is in fact a replacement card for the QL motherboard. It can display up to 256 colours with resolutions up to 1024x768 (SVGA).



The QL was sold as a professional computer, and that's why there weren't a lot of games available for it. The few that exist have a Spectrum taste... The QL was very interesting for many professionals who couldn't afford a " real " professional computer.

The QL was abondoned by Amstrad after they bought Sinclair, but several computers derived from the QL were produced, like the OPD (One Per Desk) made by ICL for the British Telecom, or the Thor made by CST.

And the passion for the QL never disapeared since even nowadays new QL compatible hardware and emulators are developed for different platforms !



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Good points dotclear.gif (172 octets) + Its low price
+ Its powerful Super Basic
+ Its multitask QDOS
+ Built-in mass-storage device
+ PSION software !
dotclear.gif (172 octets) Bad points dotclear.gif (172 octets) - Microdrives not sufficient ...
- Strange keyboard sensation
- Bad sound features
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