The Commodore 64 is one of the most successful micros on the market. Peter Worlock investigates its popularity and the wealth of software that has helped to consolidate the C64's position

The Commodore 64 is now a little under two years old, although it has been widely available for only 18 months. In the time-scale of personal computers, this makes it something of an old-timer. However, rather than being a reason for dismissing it in favour of some of the hot, new arrivals, its age acts in its favour. The C64 is now in that golden period where it has been around long enough, and sold in such numbers, that it has considerable software are peripheral support - but it still hasn't been drained of potential. Some of the best may yet be to come.

The reason for its phenomenal success is the balance between price and performance. For around £200 (less in many shops) you get an excellent technical specification: 64K RAM, 16 colours, sprite graphics, 320 x 200 high-resolution graphics and the best sound facilities of any micro. Added to this is a keybaord of near professional quality and a range of expansion options.

Of course, it is not without drawbacks. I have a vision of Commodore's corporate structure which includes a product development team, and a handicapping department. The development people come up with a computer offering more memory, more colour, better sound at a lower price than its rivals. The handicappers (who occasionally display more creativity than other departments) then throw in a truly lousy Basic and, with breathtaking of originality, add a range of non-standard interfaces that will drive many owners to despair. But thanks to third-party ingenuity, these problems are not as serious as they once were.

The C64 comes in one, largely self-contained unit. While it was never going to win any design awards, it doesn't have many faults. The power supply is an external box which gives you one extra cable but eliminates overheating problems. Even after several hours' use the C64 gets barely warm.

The keyboard is a full-travel type with a front-to-back incline that makes it suitable for touch-typing. The 66 keys include full alphanumerics, a shift-lock that really locks, four programmable function keys and a real space bar. Cursor control is from two dedicated key for down and right, shifted for up and left. There is no reset or break key, but a warm system reset can be made by use of the RUN/STOP and RESTORE keys.

Along the right side of the unit are two input ports for joysticks, light pens or paddles, the power socket and an on/off switch.

Around the back are the expansion ports. There are a large number of these but, sadly, they are non-standard. At rear right is the expansion port for cartridge software and cartridge-driven peripherals. Next come three display sockets, for TV (the C64 has a built-in modulator), and monitor, with a channel selector allowing you to tune your computer for the best display.

The main expansion bus is Commodore's own serial system which drives all C64 peripherals such as printers and disk drives. Next to that is the cassette port, followed by the user port - a parallel port that emulates both RS232 and IEEE parallel interfacing. You can attach modems, and non-Commodore devices here, or Commodore peripherals using IEEE designed for its business machines.

Although Commodore occasionally suffers a flurry of bad publicity when a batch of machines falls below standard, generally the C64 is well-constructed and reliable and complaints have never reached the proportions suffered by the likes of Sinclair and Oric.

One common moan relates to the amount of memory left free to the user - generally nowhere left free to the user - generally nowhere near the 64K advertised. The C64 actually has more than 80K of memory in RAM and ROM but the way the memory map is configured leaves about 38K free to Basic programs. If the rest, 8K is taken by the Kernal operating system, 8K by Basic ROM, 4K in I/O ROM, and 2K for screen memory and operating system storage. This leaves 42K free but a further 4K is above Basic memory.

However, a little machine code programming opens things up considerably and it is possible to reconfigure the memory map in several ways giving up to 60K free for various requirements. In high-resolution mode, for example (regardless of Oric's grossly misleading advertising for the Atmos), you can have two 8K hi-res screens and still leave your 38K untouched, a feature used by BC Basic (see the Software panel). This is a better deal than any other home computer offers.

The key to memory management is the 6510 main processor used by the C64. This is a development of the popular 6502 used by Acorn, Apple and Atari to name but a few. It has the benefit of using the same instruction set, but features two extra registers which control the way the processor looks at the memory map. In normal operation the C64 'sees' the Basic and Kernal ROMs in high memory, but by altering the registers in the 6510, it can be made to see the RAM beneath. This makes for a very flexible system but the catch is that it takes a short machine code routine to do it.

In the first instance, pretty awful. The book included free with the machine, the User Manual, is ideal for the absolute novice but most users will surpass it within a couple of weeks. The book you need is: Commodore's Programmer's Reference Guide, a 490-page tome that contains all the technical detail you need, right down to full circuit diagrams. It should be given away with the machine but at the moment you have to buy it separately at about £10 (some shops will try to charge £15 - head for the door, yelling abuse as you go).

There are dozens of independent books covering every aspect of programming and using the C64. The best have been reviewed in PCN, but a good all-purpose supplement to the Programmer's Reference Guide is Using The C64 by Pete Gerrard (£10 from Duckworth).

Ah well, everyone makes mistakes. Not to put too fine a point on it, C64 Basic is stunning in its awfulness.

It's not that it's so much worse than anyone else's, although it lacks some of the finer points like PROCedures, IF...THEN...ELSE and REPEAT...UNTIL. It's rather that having given the C64 such a tremendous hardware advantage in graphics and sound, Commodore failed to provide any Basic commands for controlling the features. Sprites, high-resolution, and sound require the programmer to delve into a morass of PEEK and POKE. Primitive? It's unforgiveable.

Taking the kindest view, there are two redeeming factors. The first is that the C64 becomes an ideal machine for learning low-level programming since you are forced to become familiar with the machine on its own terms. The second is that a great number of people have devoted a lot of time in developing alternatives to the Basic so that the C64 has more language options than most of its rivals.

The display is probably the most attractive feature of the C64. It features a range of graphics modes which give it a hard edge in the games arena.

Text display is 40 x 25 in upper and lower case. It supports sixteen colours available directly from the keyboard, and an extensive block graphics system. It is possible to redefine the entire character set and additional multicolour and extended background colour modes make it a natural winner for games. However, the real games strength comes from its sprite graphics, a set of eight 24 x 21 high-resolution characters that make sophisticated animation easy. Machine code programming increases this number considerably and some commercial games feature as many as 32 sprites on screen at once.

For more sophisticated needs, the C64 can be programmed in 320 x 200 high resolution mode in two of the 16 colours, or 160 x 200 multicolour mode which gives you four of 16 colours.

The display is memory-mapped with all graphics handled by a dedicated video chip, and the different effects, colours and modes are relatively easy to program, although the addition of INK, PAPER, BORDER, PRINT AT and MODE commands would have been welcome all the same.

Sound on the C64 is streets ahead of anything else available. Another dedicated chip, the Sound Interface Device (SID) takes care of this department although, again, there are no Basic commands to use it. This is perhaps the C64's greatest sin - since SID is so powerful, it is inevitably complex.

Among the host of features available are three independent voices, four waveforms including white noise, programmable ADSR envelopes, full filtering and special effects like ring modulation and synchronisation. With a bit of gadgetry, it's possible to use the C64 as a dedicated synthesiser, mixing outside sound sources like keyboards and guitars, with the output from SID.

This power has led to a range of software packages to allow you to get the most from the machine and some of these are truly remarkable.

Anyone who doubts the superb quality of C64 sound should try to listen to one of Alligata's games like Loco. Otherwise, suffice it to say that if you've been impressed by C64 graphics, the sound is as good or better.

Apart from the Basic, this is the major weakness of the C64. Commodore sells a dedicated cassette unit (the company claims to be one of the biggest tape deck manufacturers in the world, in which case it ought to know better). It will cost about £40 which is £15 too much, it's very reliable but chronic ('long-continued, very bad, objectionable' - Penguin English Dictionary). The trouble is that with all the memory you've got bid programs and you'll grow old and wizened waiting for them to load.

Alternatives include buying a cable that allows you to use your ordinary music cassette player, or getting one of the independent tape units which have appeared in the last few months. They're just as good and a bit cheaper.

Most games producers now use turbo-loading systems which make tape almost as fast as the 1541 disk drive. If you come across a package not using them, write the company a rude letter.

The next step is the 1541 itself. This is a monstrously large unit, almost as big as the C64 itself and it's s-l-o-w... because, for reasons known only to Commodore, it uses the serial bus which means that it sends data one bit at a time, instead of one byte at a time.

The 1541 uses single-sided disks which hold about 166K of data. The drive itself has a 6502 processor which makes it 'intelligent' (computer jargon for 'unspeakably dumb') and has the most convoluted operating system. On most disk systems you can say something like DEL to delete a file. On the 1541 you say OPEN 15,8,15:PRINT 15,"SCRATCH:filename":CLOSE15. I suspect the phrase 'user-friendly' has yet to penetrate Commodore's consciousness.

That said, there are reasons to buy the 1541, not least of which is that the best software is only available on disk and will remain so for practical reasons: software like the Infocom adventures, the SubLogic Flight Simulator, and most serious applications and business packages - good enough?

There are gizmos, gadgets, black boxes and bits of circuitry to handle just about any application. The only snag with plugging thiings into your C64 is the bizarre interfacing. The C64 claims things like RS232 and IEEE but both are non-standard implementations, and most printers are Centronics devices, not supported on the C64 at all.

But, all is not lost. There is a wide range of devices that will give you standard RS232, IEEE and Centronics I/O. Once you have these, you can do what you like.

Unmodulated output from the C64 is to composite video standard which means the choice of monitors is not as great as on some machines offering the more common RGB output. However, Commodore produces the 1701 14" colour monitor at about £200 which has medium resolution and a very crisp display. Recommended. Fidelity also makes a similar model at a similar price. Monochrome monitors are not a problem since they are all composite video.

Commodore itself supplies a range of printers from its four-pen printer/plotter, through the MPS801 and 1526 dot-matrix printers, up to its business printers running under IEE. With the addition of an interface you can also use Epson, Mannesmann-Tally Gemini or any of the other independent, quality dot-matrix printers. Even allowing for the cost of the interface, they will often supply features at better value than Commodore's products.

Commodore's own is favourite here as it simply plugs in and goes. Otherwise, any RS232 modem with suitable interface will do the job.

Endless numbers. See PCN back issues for reviews but the best ones tend to be American.

The wider display is the standard in the business world, and well-worth having for word-processing and similar applications. There are limited numbers available for the C64, most of them imported from the US and they tend to be expensive. The only one we know of in Britain comes from Zero Electronics and it sounds good. PCN will be reviewing this and others in the next few weeks. Before buying, check whether they will operate with the software you already own. Some won't.

Get hold of an American magazine like Compute! and drool. The US is a long way ahead in the add-on business. How about alternative but compatible disk drives, 128K RAM expansion boards, or a plug-in box that lets you run Apple software on your C64? All this and more at the cost of a transatlantic phone call, freight charges and a little strain on your credit card. Don't be afraid of doing it: tell them you're calling from Britain and you'll find them amazingly helpful.

Because of its features and pricing, almost anything competes with the C64 now, although when it was launched it filled an empty niche in the market. A changing market, coupled with the entry of Amstrad and Memotech, and the promise of the QL make things more difficult to define.

However, the basic advice to buyers is this: buy one of the best-sellers unless you have a good reason not to (and wanting to be different is a stupid reason), or, if you can wait for the software and expansion, pick one of the future best sellers. That narrows the field. Although there's no doubt that Amstrad will be very big, and so will the QL once Sinclair gets its act together (which won't be this year), the Spectrum remains the outstanding buy for beginners and games players, or anyone not wanting to spend too much, while the BBC now looks grossly overpriced despite its high quality.

For a while then, the C64 still looks like the best buy for the money - a respectable compromise between price and power. Neither of Commodore's new machines will compete directly and 64 owners can look forward to support and back-up well into the future. The only serious challenger is the Amstrad, provided that the software and promised attractions like disk drives are forthcoming.

In terms of fulfilling the promise of personal computers, the C64 has come closer than most. It's a superb games machine; with the alternative languages and toolkits, it's a good programmer's machine; and with the range of applications software and peripherals it's a workable machine for the small business or professional user.

Of the criticisms outlined above, none is insurmountable, nor unique to the C64 - the ideal machine isn't available yet. Any anyway, nobody said it was going to be easy... (All right, lots of people did - but they were all lying).

The following is a list of C64 suppliers. It makes no attempt to be complete.

1. Computerama, Freepost, Stafford, ST16 2BR. Mail order supplier for C64 software and peripherals.
2. Six-Four Supplies Co, PO Box 19, Whitstable, Kent CT5 1TJ. Mail order supplier for C64 software.
3. Chromasonic, 48 Junction Road, Archway, London N19 5RD. Mail order hardware, software, peripherals.
4. Audiogenic, PO Box 88, Reading, Berks. Software and peripherals including Koalapad graphics tablet.
5. Supersoft, Winchester House, Canning Road, Wealdstone, Harrow, Middlesex. Software and peripherals.
6. Zero Electronics, 149 King Street, Great Yarmouth. 80-column card, EPROM programmers, motherboards.
7. Stack, 290-298, Derby Road, Bootle, Liverpool L20 8LN. Manufacturer, expansion boards, cartridges, light pens.
8. Tomorrow's World Today, 27 Oxford Street, London W1. Software, peripherals, US imported packages.

The software available for the C64 is one of its main strengths. In terms of quality, quantity and variety of software the C64 is as well-served as any computer and better than most. And the situation is still improving as British software companies sign up licensing deals with US producers. The reason for the wealth of material in the US is simple: while British programmers concentrated their efforts on the Spectrum, their American counterparts went for the C64.

Also due considerations are conversions from other machines. Many software publishers are now moving Spectrum software to the C64, while in the US they moved it from Apple and Atari providing a rich vein of programs.

Much of this US software is already available but you'll pay import prices - perhaps as much as £35 for disk-based programs.

When it comes to games, the C64 is hard to beat. The sound and graphics facilities make it a natural for top-quality programs. While the games support took a while to roll, it's exploded recently and a glance of PCN Charts will show that while second to the Spectrum in quantity, the quality is there already. The Hobbit, Valhalla, Manic Miner - all are available for the C64. Only Ultimate continues to deal exclusively in Spectrum.

But the C64 has attracted some excellent programming in its own right. Commodore's own International Soccer is one of the most outstanding games programs available for any machine. And now the flood of US material is upping the stakes further.

War gamers should check out Strategic Simulations' range or programs. Colossus Chess from CDS compares favourably with the best chess programs around while companies like Melbourne House, Quicksilva, Supersoft, Audiogenic and Llamasoft are producing a stream of packages.

Every sort of utility is available from extensions to Basic, through assemblers and compilers to toolkits.

The best of the Basic extensions include BC Basic from Kuma and Simon's Basic from Commodore, both on cartridge at about £50. They rectify the serious omissions in C64 Basic and add a host of other commands.

Anyone looking beyond 6502 programming doesn't need to buy a new machine - get the CP/M cartridge from Commodore instead. The Z80 is the best reason for buying the package - CP/M is not a serious option on the C64 given the drawbacks of the 1541, the 40-column screen and the lack of any CP/M software in 1541 format. but a second processor for £50 is a bargain.

For 6502 loyalists the two assemblers worthy of serious consideration are Commodore's own and Mikro from Supersoft. There's a bunch of tape-based simple assemblers, disassemblers and monitors, while if you don't want to get into machine code, Oxford Computer Systems and DTL of Colchester produce a range of Basic compilers in addition to Commodore's own Petspeed 64.

For general purpose toolkits check out Adamsoft of Norwich's, Calco, which handles Master - possible the ultimate programmer's aid, more a workshop than a toolkit.

Plenty to choose from here. Forth fanciers can try Forth 64 from Audiogenic, or from Hesware; Oxford Computer Systems and Adamsoft have implementations of Pascal.

Commodore has a disk-based Logo package which is a full implementation, not just turtle graphics. All disk owners should consider buying it given the standard of Basic.

Whatever you want, they've got. The starting point is Commodore's Easy series - Script, File, Calc and Mail. They're all of a high standard and more than reasonably priced at about £50 each.

Dozens of word processors but the best include Paper, Simply Write, Vizawrite and WordPro. Databases include Superbase, Audiogenic's Magpie, Mailpro and Oracle from Kobra. For those in need of a spreadsheet, the starting point should be Microsoft's Multiplan converted from the IBM PC. Others include Supersoft's Busicalc and Practicorp's Practicalc. Plus uncountable packages for more specialised applications including accounting, stock control, sales and purchase ledgers.