Old fashioned perhaps, but Amstrad's micro is a very attractive machine, says Max Phillips

Amstrad is the latest in a long line of electronics bad boys to notice that micros are slightly more substantial than skateboards and hula hoops. It started thinking about putting its undoubted manufacturing and design talents towards a home machine (for the record, a 6502-based 'improved Vic') over a year ago. This project was replaced with discussions of the great MSX stitch-up but Amstrad was worried about the MSX spec, the ridiculous hassle of getting an MSX system together and the fact that, if it made it, it would only be competing with 20 or so nearly identical products.

So it was only last September that the Amstrad micro really got off the ground. The machine, code-name Arnold, is more-or-less a traditional Z80-based home micro. But Amstrad has learned a lot from everyone else and the machine is a very mature design with many of the best features of rivals and almost none of their mistakes. In short, as you might guess, Amstrad has done a very professional job.

Sadly, the name Arnold has been left behind. It's a Colour Personal Computer with 64K RAM and would have been called a CPC64. But, the story goes, following the announcement of Commodore's 264 and 364 machines, Amstrad decided to go one better and have a 464. Hence the name CPC464. At least the story is more interesting than the name.

The CPC464 will be available in limited quantities as you read this. This is not, unlike some companies we could name, because Amstrad can't build the machine but a deliberate policy to give the software houses and add-ons firms a headstart before the company really starts selling the product in September. This preview is based on a day's play with the machine rather than weeks of constant use and you would do well to be wary of the product until Amstrad is shipping it in quantity. Even so, the machine is all but ready and it's well worth knowing about.

Of course, Amstrad is all about what's rather indelicately called cheap hi-fi. With Amstrad, you get tremendous value but you accept that the equipment is not perhaps of the quality of bigger names such as Sony and JVC. The same is true for the new machine - it offers dramatic value for money. However, the twist is that, compared to the shoddy standards of some micro manufacturers, the Amstrad micro is beautifully designed and engineered.

The value is obvious. For £200, you get a 64K, Z80-based micro with a full keyboard, a built-in high-speed cassette recorder and you get a 12" green screen monitor. For £300, the machine comes with a medium-resolution RGB monitor. The 464 doesn't connect to a TV like every other home micro - the idea sensibly being to give you a trouble-free quality display that can do 80 columns and to leave the TV free for more humble jobs such as Channel 4 and video recorders.

It's harder to assess the quality of engineering. You should really wait until the machines are in the shops and try one for yourself but the 464 feels solid and reliable. Minor points of design, such as the copious venting and a printed circuit board that is mounted with an inch of air either side of it, suggest that you are getting a lot for your money. Whether or not the machines can stand up to long term use remains to be seen; but the signs are good.

The 464 is larger than you'd expect but it has that increasingly long and thin fashionable shape that is actually very nice to work with. The conventional qwerty keyboard is on the left, followed by a numeric keyboard and cursor pad, followed by the built-in cassette recorder. At the right are two controls - an on/off switch and a volume control on the integral speaker - at long last. Round the back are the interfaces with a few edge connectors showing some of the cost savings that have been made.

The first surprise is that the micro takes its 5V power from the monitor. Two short leads connect the two units together - one power, one the signal (composite or RGB) for the monitor. Guess what? You only need one plug to run the whole system. It has been said that Amstrad is making a major breakthrough by integrating all the bits of a micro system and putting it in easily handled lump. My Osborne does it, the world's first personal computer, those old Commodore PET things, and the all-in-one-box philosophy completely sorted out. But it is very nice to work with a home machine where there is no messing about with cables and sockets and that you can pick up and move when you want to.

The only possible problem might be for users who don't like to get too close to the screen.

The computer itself is a bit old-hat these days though it is beautifully done. There's a 4MHz, Z80 with 64K RAM and 32K ROM. The top 16K RAM and 32K ROM. The top 16K RAM is the screen memory and is bank-switched with the 16K Basic ROM. This leaves a more than healthy 43K free for Basic programs.

Similarly, the bottom 16K RAM and ROM can be switched over. Many micros have their screen memory part of main memory in this way. The processor and display chip (a 6845) must carefully split their time over which has access to the screen memory and this can produce a slow system. The 464 and its built-in software don't seem to be affected by this problem.

The software has provision to go on extending the memory map to ridiculous sizes in the order of 4Mb. This is provided so that add-ons can contain their own driving software and so that plug-in-and-run cartridges can be used. It is obvious that Amstrad doesn't intend to leave the system as its stands but to expand it to a complete range of options.

The Amstrad has a full keyboard with 75 keys. It doesn't feel like the world's most expensive keyboard but it is good enough for fast typing.

The layout is fairly standard, the only quibbles being the curious position of the Control key and a non-locking CAPS LOCK key. Typists who know where to put their fingers may also find that the stretch to the ENTER, DEL and cursor keys is something of a shock. There are one or two labelling oddities - the square bracket keys produce braces ( { and } ) when shifted and the CLR key generates a DELETE-RIGHT for the Basic editor.

If we skip ahead a little, you can get a good idea of the sort of software that's gone into this machine. As part of the Basic (and operating system), the entire keyboard is redefinable. So you can say which keys generate which ASCII codes and also whether they auto-repeat and what they generate when shifted or controlled. For example, KEY DEF 68,1,13 turns the TAB key into another ENTER key.

What's more, 32 ASCII codes (128-159) can be used as function keys. Any key generating one of these codes can have a string of up to 32 characters associated with it (provided the total of all the function keys doesn't exceed 120 characters). So not only can you have 32 function keys, you can position them where you like around the keyboard. The nicest system seems to be to put ten common Basic commands on the numeric pad but lots of other customisations are possible.

With a standard Amstrad, you are stuck with either the monochrome green screen or the RGB monitor; neither was particularly impressive although with such low-cost parts you do expect a lot of variation between units, and review systems are invariably heavily knocked about.

The green screen is an angled 12" monitor with no anti-glare coating. It needs to be carefully positioned or else you'll get a contrast-free display with a picture of your room in it. The review model also undulated to the point where it was unusable - again, probably just the review sample.

The RGB monitor is much more impressive, producing bright colours. However, Amstrad has cut corners with the monitor's resolution and admits that the screen can't quite cope with the 464's 640x200, 80-column display mode. The result is that 80-column text is not very readable - you can read it, particularly if you choose your colours carefully. But I'd hate to try sitting down and reading screenfuls of text for four hours at a go. Rather disappointingly, some micros and some TVs can match the quality of the 80-column screen on this dedicated monitor.

Amstrad's solution to this rather daft problem is to offer the monochrome monitor for those who want to word process or whatever. To get the colour back, the company is then going to offer a combined modulator/power supply for £30 so that you can connect the system to your TV. Amstrad seriously believes that most people will buy the black-and-white machine and then come back and pay £30 extra so that they can ignore the monitor/power supply they have just bought and connect the system to the TV they owned all along. Tut, tut!

The display itself is a bit-mapped screen generated by a 6845 and provides three modes:

160 x 200 graphics, 16 colours chosen from 27, 20 x 24 text
320 x 200 graphics, 4 colours chosen from 27, 40 x 24 text
640 x 200 graphics, 2 colours chosen from 27, 80 x 24 text

In addition, the border can be set and there are several flashing colours available. The system can also do tricks like a hardware-assisted scroll in any of the four directions. Surprisingly, the majority of the 27 colours are genuine and bright tones - very useful for creative graphics. The video memory occupies the top 16K RAM and each of the modes uses the same amount of memory, so that there is no extra overhead for being in 80-columns as there is on machines like the BBC. Incidentally, it should be possible to set up other modes by direct access to the 6845.

Like almost everyone else, Amstrad has gone for the General Instruments 8910 3-voice sound chip to provide three synthesised channels and one noise channel. But it's been done very sensibly. The sound is stereo - voice one goes to the left channel, voice two to both and voice three to the right hand channel. Even on something as simple as durrel's Harrier Attack (yes, it runs on the 464 as well as the Spectrum!), the stereo sound is surprisingly effective.

Of course, to take advantage of this, you'll need either headphones or to position your micro between your hi-fi speakers. If you can't be bothered, there's a rather tinny speaker built into the machine itself. It's refreshing to see someone actually produce the stereo sound.

The sound chip is also extremely well supported from the Basic. There are more sound commands than on any machine with an equivalent chip so you can do proper chords, rhythms, sound queuing and define your own envelopes to imitate real noises and instruments. So you've more control than on most systems but don't expect it to be particularly easy.

Amstrad has taken away most of the problems of cassette storage by building a dedicated unit into the console. This operates at a healthy 1000 or 2000 baud; you don't have to worry which one as the correct speed is automatically selected by the 464 as it reads the tape. The machine also have the equivalent of a REMote lead, giving it control over the tape motor. However, Amstrad hasn't taken full advantage of the situation. The tape is manually controlled and there is no provision for audio tracks to be reproduced through the machine. The unit seemed to operate reliably but, rather curiously, very slowly.

Amstrad doesn't expect to have disks ready until September. You shouldn't go overboard at the prospect of turning your 464 into a CP/M business computer either. If you've got 64K RAM with 16K of video memory, that leaves you 48K of space for CP/M. Most CP/M programs will run but the level of disk overlaying and access will be quite something.

The 464 has a rather curious collection of connections. The main one is an expansion bus labelled 'floppy disk' which will allow almost any device to be hooked to the system. There's a Centronics printer interface and a joystick interface. The latter is an extended Atari-standard, allowing two fire buttons and a second stick to be plugged in via the first! Besides the power in and monitor out connectors, the only other jack is a headphone-style output for the stereo sound.

It's worth nothing that the company has produced piles of technical documentation and that this will be available to qualified parties. It is available now (for a price!) to companies that want to be ready for the major launch in September 1984.

The 464 is extremely well put together, both in terms of hardware and software. Being a home machine, it operates in Basic - a fast and extensive implementation of the little known Locomotive Basic. However, the 464 has a completely separate Operating System which handles most of Basic's clever tricks for it in a complex piece of hardware using a ready-made and well documented set of supporting routines.

The Operating System is completely transparent rather than the messy *FX and VDU calls of the BBC. Everything, apart from a series of control codes to look after the screen, has its own Basic keyword.

Locomotive Basic is extremely nice to work with. It's very fast - certainly fast enough for simple graphics games - and it has a set of extensions that make the machine very approachable and versatile. Although there isn't room to give a full description of the Basic, it's evidence that there have been two guiding principles behind its implementation. First, it's pretty close to Microsoft and it shouldn't be too hard using other people's listings on the machine.

Second, Basic provides everything. There's almost no need for PEEKs and POKEs and all the facilities of the machine have a keyword. As an example, to write text at any particular pixel on the BBC you join the text and graphics cursors together - VDU 5 (or was it *FX5?). On the Amstrad, you just join the cursors together with TAG and TAGOFF. It's all that simple. If you want a home computer to learn Basic, the Amstrad is ideal.

Program development is greatly speeded by having both a line editor and a screen editor at the same time. This is a rather brute-force 'best of both worlds' idea and a slightly more sophisticated line editor would have been welcome. However, the result is very helpful indeed. You've also got the usual RENUM, TRON and TROFF.

Graphics are easy to do. MODE selects one of the three display modes and you've got commands to draw lines and points. Probably the biggest obvious weakness of the Basic is that there are no CIRCLE and PAINT commands. You do get user-definable characters with the SYMBOL command. SYMBOL AFTER even lets you retain a section of the ROM character definitions and mix them with your own new characters.

Colour is easily handled. PAPER sets the background colour and PEN selects one of the available foreground colours (either 16, 5 or 2 depending on the mode). INK is used to select the colours that PEN actually produces. So you can use INK first or fall to select from the range of 27 available colours. Changing INK with that particular PEN colour already on the screen causes the new colour to magically replace the old. this can be very useful for fast animation effects.

Amstrad Basic has a timer/interrupt ability that, with the possible exception of the ill-fated Comx 35, is unique among Basics. There are four programmable timers which act a bit like alarm clocks. The command AFTER 200,2 GOSUB 1000 will do a GOSUB to line 1000 after 200*0.02 seconds using timer 2. The four timers have a priority order so that you can establish an importance for your interrupt routines. The Z80ish instructions DI and EI turn the interrupts on and off so that, for example, interrupt routines don't get interrupted.

EVERY works like AFTER except it repeatedly calls the subroutine at a given interval. Imagine an EVERY command which caused the system to update an on-screen clock every five seconds. Or one that lets an interrupt routine place the next note of a tune in the sound queue while the main program played a game. Look mum, two tasks! Interrupts are very new to Basic programmers but, used properly, that can be a staggeringly powerful aid.

The Amstrad also supports eight on-screen windows. Only jokingly of course - it's the same pseudo-windowing system used on the Sinclair QL. Each window is a particular output channel (PRINT#0, PRINT#1 and so on) with its own background and foreground colours and its own position on the screen. It looks like a windowing system but the windows don't have any 'contents' as such and where windows overlap, the lower ones are destroyed. The 464 has one important facility that got left out on the QL: the default output channel can be moved to any of the windows. And, using EVERY and AFTER on the Amstrad, it's easy to make it look as if the machine is multi-tasking. Even so, the window system is no more than a potentially useful screen handling gimmick.

Briefly describing any Basic this size will miss out on some of its sweet little features. It's got all sorts of bells and whistles - UPPER$ and LOWER$ for folding strings to upper and lower case. Even a command called ZONE which sets the column width introduced by using a comma in a PRINT statement. Amstrad Basic has been designed by people who know what they are doing.

Neither has Amstrad fallen for the oldie of launching a machine with no software to choose from. Quite the contrary. Early machines have been out with software houses from January and the initial limited supply period is intended deliberately so that when the company has its big selling push in the autumn, there'll be lots of programs to go for.

There are already around fifty titles including familiar names such as Harrier Attack and something that looks not unlike Booga-Boo. The quality is quite remarkable. Some of the games are churned out in Locomotive Basic but you'd be hard put to realise that from the way they look. Incidentally, the Basic has a SAVE ,P option which SAVEs a protected version of the listing to stop it being examined. Told you there was no need to mess around with POKEs.

Amstrad has set up a division called Amsoft to look after the machine and launch 'official' software. Some of the plans are quite remarkable as well as ambitious. Hisoft is porting its Spectrum Pascal and C compilers onto the system. There are spreadsheets and word processors being discussed - the Operating System would allow these as external ROMs. And there's a good chance that the CP/M version of the machine will be bundled with a choice of business, accounting, programming or games software.

Amsoft also seems to be taking packaging seriously and is producing proper manuals for cassette-based programs. You never can tell how a new machine will be received and supported - particularly when it comes from a brand-new supplier. But at the moment, things are looking good.

The manuals are only at a preliminary stage but even the first machines to go to customers will have their User Guides in a printed form. This covers all the usual stuff, including the Basic, with an unusual amount of clarity and depth. There's also lots of introductory stuff for computer-shy newcomers. Amsoft claims to have written the manual in two weeks; something you'd never guess from the quality of the work.

However, more in-depth technical information such as the internals of the Operating System and hardware details will be separately priced manuals. Most users won't need these although anyone who gets into programming will undoubtedly want one. These manuals are currently available in photocopied form for £20 a go.

No matter how nice it is, don't forget that Amstrad's new micro is rather old fashioned. That's a very cruel judgement on what is one of the most capable, mature and usable of home computers yet. Even so, this is a Z80 and 64K RAM micro that won't be around until September. There's also every probability that the CP/M version of the machine won't be so wonderful. Amstrad has taken the wise route of sticking to old established technology to provide an affordable and reliable system.

So you can rest assured that it is an easy and capable machine that offers tremendous value for money. You also get a machine which is, on this short analysis, more attractive than the first generation of MSX systems.

Amstrad also threatens to be big with the system and to create a Sinclair/Acorn sized software and add-on market. It has a too-big-to-print estimate of its first year's worldwide sales that would make the Spectrum look like a failure.

In short, it's a great home computer - if a little late, and provided that machines don't fall apart after a month. Keep an eye on it... it could be a very enjoyable micro to own.