Sinclair QL - A Technical Review

The Sinclair QL was what Sinclair Research Ltd (SRL) hoped would become the first choice for the business user. This may seem misguided today but at the time it had the edge over most other systems in terms of both price and functionality. It's main downfall was that it didn't run industry standard software and it's business aspirations cane to nothing. But as a small business and home computer (these days referred to as the SOHO market) it was absolutely ideal. No other machine gave the user access to a range of integrated business applications (long before Office suites became fashionable) let alone at the price (£399). It also had an advanced architecture not unlike the Atari ST that was still a twinkle in the eye of Jack Tramiel and is still being supported and developed to this day by enthusiasts. The only 1980's computer that still has that accolade is the IBM PC (although the Amiga might yet make it to the market place, at the time of writing). And it is the architecture that will be the focus of this article.

The QL has much in common with it's predecessor, the Spectrum which goes a long way to explaining it's price tag. It can be plugged into a TV set, Microdrives formed the storage medium, it had an expansion slot for peripherals, a reset button, it shared the rubber membrane keyboard and had network and printer connections identical to those of Interface 1. It also had a few extras. A ROM cartidge slot though sadly incompatible with the Spectrum's Interface 2. A monitor socket similar to that found on the later Spectrum 128. It boasted two joystick ports but with non standard connectors ( a regretable Sinclair trait). A second microprocessor (Intel 8049) handled the keyboard, sound and serial ports. The onboard BASIC (called SuperBASIC) had some compatibility with Spectrum BASIC but was largely incompatible. The Central Processor Unit (CPU) was now a Motorola 68008 (more on that later). The ROM was expanded to 32k (the same as on the Spectrum 128) and RAM was 128k (ditto) as standard. It came bundled with a suite of business software (by Psion) consisting of Word Processor (Quill), Spreadsheet (Abacus), Database (Archive) and graphing module (Easel). All in all, a powerful machine. The documentation was to the usual high Sinclair standard in a nice stout folder and it all came in a silver box with a carrying handle. That's the bones of it. Now for some flesh.

The QL was late getting to market. Only about a month or so but late nevertheless. These day's that hardly constitutes late at all. We're still waiting for NT 5 (at the time of writing). But at the time much was made of it. The essence of the problem was the operating system. In line with previous Sinclair kit, the OS was in ROM. Cramming it all in had been a bit of a trial. The machine was eventually shipped with a board hanging out of the back of the ROM cart slot with the promise of an upgrade. Loading it from microdrive might have made more sense but at least the machine doesn't take forever to load the OS (unlike my PC!). There have been a few upgrades to the ROM since. These are the ones I know about.

    AH 		The earliest

    JS 		One of the better ones

    JM 		Latest Sinclair

    MG 		Special language version

    Minerva 	A third party replacement

Rumour has it that the letter codes were initials of people working within SRL. They were upgraded principally to rectify bugs in the code. Even the later JM is not without it's problems (to numerous to list here). Minerva is undoubtably the best upgrade but it isn't cheap. Most bugs however will probably never be felt by the user (I use an AH with no problems).

Now the Processor. The Motorola 68000 series is a fine processor with an excellent heritage (6800 found in the Dragon) and later used by Apple, Atari and Commodore (Mac, ST and Amiga). The 68008 SRL chose to use was a had only an 8 bit bus although internally it was 32 bit (the ST had a 16 bit bus) which makes somewhat slower. In fact at 7.5 mhz, the computer isn't running much quicker than the Z80 found in the Sam Coupe. Add to this the fact that the screen update is rather slow (there wasn't any room to put faster routines in the ROM) and that internal memory is slower than external and all in all not a performance monster it should have been. Suffice to say that all these problems were rectified by third party companies at a price.

Microdrives. Of all the features of the QL, these got the most criticism. I would like to say here and now that I have NEVER experienced any problems with loss of data using microdrive. They are considerably more reliable than 3 inch disks in my experience which suddenly become unreadable for no good reason and seem fine after formatting. If a microdrive cartridge does give problems then a cartidge doctor usually manages to recover most or all of the data although the cart has to be binned afterwards. Failures are rare. When the QL first came out, the tape used in the carts may have been inferior but later carts seem fine. There are only two problems with them. They will only hold around 100k of data and they are expensive to buy (although cheaper than 3 inch disks). That apart, for a computer with memory of 128k, they are perfectly adequate. Pity the Spectrum 128 didn't come with them built in as standard. But with the advent of extra memory, they become unwieldy and the addition of a floppy drive becomes inevitable.

Microdrives work in much the same way that a floppy disk works except that it's on a long tape loop. It has to be formatted with special marks telling the OS where everything is. It has header information about the sizes of files and has a read/write tab to prevent overwriting. Files can be listed using the DIR command and the drives are numbered mdv1 and mdv2 with the possibility of adding more Spectrum units by plugging them in a slot in the side of the machine to a maximum of 6 (8 drives altogether). However, the format process is different to the Spectrum so that a Spectrum formatted cart cannot be read by the QL and vice versa. Pity that.

Memory. Memory is restricted to 128k on the motherboard although I have heard remours that more can be piggy-back soldered. A better solution is to use the expansion slot and add a memory unit that usually came with a floppy drive connector and toolkit in ROM. I have a 256k expansion unit taking memory up to 384k. At one time it was thought that an extra 512k (640k) was the maximum but then a company called Miracle Systems came up with the Trump Card bringing memory to a grand total of 896k by stealing some memory allocated for the ROM cart. The PC is today is hard pushed to find 620k in it's first 1 meg of memory without resorting to extra memory banks. The extra memory was also much faster than internal thus making a slight difference in speed.

Addons. The sale of Sinclair to Amstrad saw an end to official development but there has been plenty of unofficial development going on. As alluded to above, disk drives can be added quite easily. I have twin 720k drives referred to as flp1 and flp2 but these were not devices supported by QDOS but by third parties and required extra software to make full use of the drives and Toolkit II became the standard adding extra commands such as wildcard copy commands. Hard Drives are now also supported with them the ability to create directories. Expansion was taken a step further with the advent of the Gold Card (and it's successors) that had a faster version of the CPU, a 68020, and extra memory up to 4 megs.

The QL has become a very efficient business machine but too late for SRL. The QL is an enthusiasts dream with an architecture that is easily expandable and well documented. There is a constant stream of new hardware being created for it and a new operating system has been written. There is a flourishing User group (QUANTA) and a bi-monthly magazine (QL Today). Things have never been brighter for the QL. Long may it continue.