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Amiga - Theory And Practice

Article from Electronics & Music Maker, August 1986

David Ellis buys a Commodore Amiga and looks at the latest software written for it. The music is good, the graphics are better - but what does the future hold?

Commodore's Amiga is now in the shops after months of speculation, procrastination, and hype. But what's the software situation like for the musically inclined Amiga user, and is the long-term future a rosy one?

A COUPLE OF MONTHS AGO, I took the plunge and purchased a Commodore Amiga. Well, having eulogised over it in a Newsdesk report (E&MM October '85) on last year's PCW computer show, it was the only decent thing to do. I should also own up to a rather generous discount from Commodore which certainly swayed my purchase decision-making. In fact, just about all the computer journalists in the UK were offered a similar carrot, which probably explains why Commodore were able to announce that all the first 1000 Amigas imported into the UK went in just two weeks.

As most of the computer world will probably know by now, the Amiga was originally going to be known as the Lorraine, and was scheduled for release early in 1985. After a lot of expensive chip development work, things went a bit sour financially, with the result that the Amiga Corporation ended up in partnership with Commodore as Commodore-Amiga. Now, if you look inside the Amiga's lid, you'll find inscribed on its underside the signatures of all 53 of the Amiga Corporation's employees - plus the pawprint of their pet pooch. A sort of Parthian shot aimed at the fickle computer industry, I guess. Quite touching.

Like the Macintosh and the current Atari ST range, the Amiga uses a 16/32-bit 68000 processor. This is a nice processor, and it's made all the more nice by the fact that it works in conjunction with a trio of customised chips designed by Amiga Corporation's Jay Miner.

One of the most exciting hardware devices in these chips is the blitter. Standing for 'block image transferrer', this is responsible for shifting blocks of data in RAM at ultra-fast speeds - up to ten times faster than the 68000 itself, in fact. That may sound like the hyperbole from which advertising copy is grown, but it's the blitter that gives the Amiga its terrific potential in the area of animated graphics - a potential that has been recognised by BBC TV, who are reputed to have acquired a quartet of Amigas for paintbox-type graphics on the cheap.

A further characteristic that the Amiga shares with the Macintosh and STs is its adherence to the WIMPS philosophy. Briefly, this means that every computing activity takes place inside on-screen windows. Because the Amiga is multi-tasking (meaning that several programs can be run concurrently - unlike the Mac or STs), a number of programs can be run from their individual windows and displayed at the same time - almost like watching several TV screens at once. User interaction with the windows is achieved simply by moving a mouse-controlled pointer to a relevant icon, and double-clicking the left-hand mouse button to select and run that program. It really couldn't be easier, and even though I wasn't a mouse man before, I found myself taking to it like... well, a mouse to cheese, perhaps.

One criticism that's been levelled at the Amiga is its limited amount of onboard RAM. After years of putting up with an Apple II's 48K and a BBC Micro's 32K, I thought at first that the criticism was a mite unfair. But by the 1Mbyte standard of the Atari 1040ST, I have to concede that the basic complement of 256K does seem pretty mean. It's one feature of the Amiga that shows how long it's been in development - no one would have sneered at 256K a few years back.

Fortunately, the UK Amiga system includes as standard an extra 256K that plugs into the front of the Amiga much like a game cartridge (though it's hidden from view). The resultant 512K sounds much more reasonable, and, indeed, it would be on any other machine. But because the Amiga can run several programs at the same time, and because these programs tend to be written in memory-greedy, high-level languages, that 512K gets chewed up like nobody's business. So the first addon the average Amiga user is sure to look for is extra RAM. Trouble is, add-on companies are being extremely greedy in this respect. I mean, would you willingly pay £1200 for another 2Mbyte of memory after spending near £2000 on the machine itself?

BUT BACK, AS THEY SAY, to the music - or rather the lack of it. Because for all the noise that's been made about the Amiga's sound and music capabilities - Rick Wakeman at a recent computer show, Andy Warhol and his gang of audiovisual artistes (Debbie Harry included) at the Amiga's US launch - remarkably little music software of pro quality has appeared.

Before the carping, though, let me recap what the Amiga is claimed to do in this department. Basically, sound production is taken care of by a custom chip called, in an ingratiatingly friendly and typically laid-back American way, Paula. This contains a couple of eight-bit companding DACs, each of which can be fed two channels of waveform data from RAM, along with pitch info and precise (well, 64 levels) specifications for volume. And all that takes place at a maximum sampling rate of 29kHz. Pretty impressive, you're bound to agree. In fact, from those specs, you'd expect the Amiga to sound every bit as good as an Emulator I, Fairlight Series I, Akai S612, or Mirage. But it doesn't. Or at least, that's not the impression given by the software I've heard.

One metaphorical fly in the ointment is the pair of low-pass filters on the outputs of those DACs. According to the Amiga hardware manual (not the one that comes with the system, but one costing an extra $20), these filters start to cut off at 5kHz, and complete their dirty deed by 7.5kHz. That seems strange - surely a 29kHz sampling rate should be given the benefit of the doubt and allowed to emerge in all its glory up to around 13kHz? While that's not a question which has found its way onto the agenda of the PM's question time, it is one that I've put to Commodore UK. So far, though, no response.

One reason for those filtering characteristics may lie with the fact that Paula's DACs are also responsible for regurgitating synthesised speech. Because included in the Amiga's ROMs are some clever routines for translating text into phonetics, and then phonetics into speech. It sounds good, too. It'll even say 'E&MM is the greatest' without mentioning Zlatna Panega or asking for free ad space.

So, what software is available? Well, I've had a chance to look at 'pre-release' versions of two programs called Musicraft and Harmony, both from Cherry Lane Technologies. Superficially, Musicraft is much like any Commodore 64 software, with one display showing a pair of staves and another dealing with sound synthesis.

The notational aspect is actually rather disappointing, and certainly way below the quality of either Mark of the Unicorn's Professional Composer or Southworth's Total Music for the Macintosh. That's the fault of the Amiga's problematic high-resolution graphics - more on them later. Although entering notes is reasonably fast, the program is strangely idiosyncratic in some respects. For example, it refuses to acknowledge that you might want to use notes of a duration less than a semiquaver (16th-note). Nor does it allow triplets or any other sort of n-tuplet. And it doesn't accept that it's valid to have a B-flat accidental in the key of C major, either. Perhaps all these curiosities will be corrected in the final release version.

More interesting is the synthesis side of Musicraft. This cunningly emulates an analogue synth, even down to allowing phasing and sync effects to be added to each of its four channels. Adding extra harmonics to a basic waveform is also possible, and by moving the mouse over to the 'OK' box, the new waveform is calculated (very quickly) and stored in RAM. The VCF responds much faster to its mouse-operated controls than you'd expect from a standard software simulation of filtering, so there must be some rather clever filtering algorithms at work.

"The notational aspect of Musicraft is rather disappointing, and that's the fault of the Amiga's problematic high-resolution graphics."

Sound-wise, though, the synth simulation is on the noisy side, and lacks the sharpness that would be gained from a better output bandwidth from the Amiga's DACs. Interestingly, some of the demo sounds were real samples, but the version of Musicraft I saw didn't seem to have any provision for either user sampling or modification of the ones supplied. Also on the negative side is the complete absence of facilities for linking up Musicraft with MIDI equipment or using any sort of keyboard as a note input device.

In sum, then, a mediocre scoring program with an imaginative synth section.

Harmony is a different beast altogether, and one that's very much angled at the educational market. It's also one of the first pieces of music software I've seen to claim the influence of artificial intelligence (or AI, for those that prefer their jargon short and sweet). I suppose Kurzweil ought to get a mention here, but I've never been that convinced by their description of musical AI. Harmony stems from some work at Carnegie-Mellon University in the US that took a long, hard look at the nature of musical accompaniment.

Put simply, Harmony displays the lead line of some ten or so popular classics and gets you to play it on either a MIDI or passive keyboard. The software then analyses your 'performance' in real time and accompanies you in four parts. If you change dynamics, the accompaniment changes accordingly; if you speed up or slow down, it does exactly the same; and if you stop and start somewhere else in the piece, Harmony works out exactly where you've got to without swearing at you or emptying a pint of beer over your head. You can also adjust the 'personality' of the accompaniment by changing the values of such intriguing parameters as 'patience' and 'anticipation' from a further pull-down menu.

And if you can't read the dots, there's the option of following a red key that leaps up and down the length of the displayed keyboard with something approaching gay abandon. Another option allows you to re-orchestrate the accompaniment.

If you've unwisely chosen 'Yankee Doodle Dandy' to play with, you might feel it essential to re-orchestrate with anything other than the curiously named 'goodpipe'. All the instrumental sounds on offer seem to have a sampled origin, and some - the violin and trumpet, for instance - actually sound quite respectable. One (major) problem is that there doesn't seem to be any provision for putting in your own tunes and accompaniment, so I guess Cherry Lane are intending people to buy extra disks of arrangements.

In sum, then, a fun piece of software that combines intelligence and good looks, but with a limited outlook on life.

Cherry Lane's Amiga products don't stop there, either. Their Pitchrider, for example, is an ingenious program that turns the Amiga into a monophonic pitch-tracker for controlling a MIDI synth. The US launch of the Amiga had a sax player working with a combination of Pitchrider, Harmony, and an external synth, to impressive effect.

Finally, there's the more upmarket Texture program, which is said to be an extensive sequencer with some form of graphics shorthand for notation.

The one problem facing the release and distribution of all these programs is that Cherry Lane are reputed to have stopped dealing in music software. Whether that's because they tried to do too much too fast, or whether it's an indication of the troubled state of Amiga software development, is anyone's guess. But it does mean the Amiga user probably can't count on getting hold of these products at present.

One further Amiga product that Cherry Lane were intending to bring out was, not surprisingly, a MIDI interface. Unlike Atari, who sensibly went ahead and put a MIDI In and Out as standard on the ST range, Commodore-Amiga opted for a programmable RS232 interface. What that means is that the Amiga can send and receive serial data at the standard MIDI rate, but to do this properly, you need a few extra components to turn the RS232 interface into something five-pin DIN leads can be plugged into.

"Mimetics have built a system around the Amiga's strongest point — the multi-tasking—rather than attempting to emulate the Macintosh's ultra-crisp display."

For a computer so well endowed with interfaces in one shape or form, it's curious that a companding ADC wasn't included in Paula to accompany the two DACs. Still, there's no shortage of companies ready to make up for the deficiency, with no less than four sound digitising packages already available or imminent. Two of these are slanted particularly at the Sample And Regurgitate brigade; the other two are more musically inclined.

The Micro Forge Stereo Sound Digitizer comes into the first category, but, at a UK price of £345 + VAT for a stereo ADC card with a handful of chips on it, which also requires an expansion system (a minimum investment of £250 for a single slot system, or £700 for seven slots) before it'll even make meaningful noises with the Amiga, it's pretty detached from any conventional notions of value for money.

Much better value, at $175, is the FutureSound digital sound recorder, from Applied Visions. This comes with a microphone, and simply plugs into the Amiga's parallel port, enabling high-quality sampling up to about 28kHz.

Given all this interest on the sampling side, it's not surprising that Amiga games are appearing which make good use of samples. Particularly effective is the game One-on-One, with sampled crowd noises, ball thunk, hot-dog vendor, et al. The only drawback is the game itself, which is a dreary (for me, anyway) basketball simulation. The excellent Arctic Fox is a further example of imaginative sampling, and it's a game written specifically for the Amiga, rather than just another Commodore 64 conversion.

From my admittedly short-term reading of the software situation, the brightest hope for Amiga music would seem to lie with Californian company Mimetics, and Music Sales' Mixdown system previewed in last month's E&MM. It's both of these that provide facilities for musical sound sampling.

Mimetics' SoundScape system comprises three separate products: SoundScape Pro MIDI Studio ($149), SoundScape Digital Sampler ($99), and an Amiga MIDI interface ($49). Judging by current trends in the UK pricing of Amiga software, those figures will turn directly into pounds sterling. However, even an end result of £300 should be fair if SoundScape lives up to its spec sheet.

What Mimetics have done is to build a system around the Amiga's strongest point - the multitasking. So, rather than attempting vainly to emulate the Macintosh's ultra-crisp display, they've given the user the option to mix 'n' match as many as 32 different modules, using the Amiga's facility of multiple windows, all routed through a main icon-driven patch panel. Thus one module provides an internal MIDI clock with autolocate and function controls, another allows four-voice, eight-bit companded sampling at a rate of up to 30kHz, with definable ADSR, loop points, pitch-bend, and velocity, and a further module is a tape deck with an 'infinite' (according to Mimetics) number of tracks and notes, plus full sequence and song editing, and selectable MIDI filters on In and Out.

To describe this concept as exciting is putting it mildly, though it'll doubtless take some getting used to. A full review should follow shortly, so watch this space.

Yet although the Amiga's sound is impressive, especially when compared to previous personal computers, it's in the area of graphics that the machine has delivered more than mere promises. Graphics on the Amiga breaks down to five different modes: two lots of low resolution (320x200 and 320x400 pixels, both with 32 colours out of a choice of 4096); two lots of high resolution (640 X 200 and 640 x 400, both with 16 colours); and a special 'hold-and-modify' mode that allows all 4096 colours to be displayed on-screen at the same time in any resolution. On top of that, there are some sophisticated animation routines built into the Amiga's ROMs that enable it to do such a convincing job of moving the robots, dog, and fire hydrant to such convincing effect in the much-seen 'Robocity' program.

Just how good the Amiga's graphics can be is demonstrated by the Digi-View video digitising hardware (around $200) from American company NewTek. This box of tricks interfaces between any standard 2:1 interlace monochrome video camera and the Amiga's parallel port. By scanning an image using RGB colour filters - a different one on each of three ten-second passes - you end up with a high resolution image with up to 4096 colours, which looks almost as good as television-quality video.

The only problem is that there's no means of doing anything with the digitised images, other than a bit of recolouring and assembling into a glorified slide show. In theory, at least, it should be possible to use them for painting and animation, but, as is so often the case with nice ideas, it's all just vapourware at present.

"If the Amiga?s sound is good and its graphics are excellent, there's clearly scope for software that combines both... and that could help cross any boundary between the musical and visual arts."

Other video options on the horizon are the Live! frame grabber, which is claimed to digitise in real time at 20 frames per second, and a Genlock interface that should enable the Amiga to synchronise to any video source and superimpose text, graphics, or whatever. The last two add-ons are both from Commodore-Amiga themselves.

Standard graphics, however, are based on the low- and high-resolution modes. And it's here that the flaws in the mould start to appear.

The first unfortunate fact is that 400 lines on the Amiga's display can only be achieved by using a special interlaced mode that doubles the vertical resolution at the expense of halving the screen's refresh rate. As a result, any mode with 400 lines flickers terribly, which more or less puts paid to any ideas of constructing Mac lookalike displays with 16 colours. For me, that's a major disappointment.

The second limitation lies with the blitter's inability to cope with more than the Amiga's expanded 512K of RAM. Since it's the blitter that takes the lion's share of the work involved in animation, and since any really serious animation is likely to need more than just that 512K, the Amiga is going to come a little unstuck. It's said that the forthcoming Amiga 2 (what, a new machine already? - Ed) will both quadruple the amount of RAM and extend the blitter to cover it, but that's hardly any consolation for owners of the current Amiga.

But on to the graphics software that's actually available. The two main products that have so far appeared are Deluxe Paint (around $100) from Electronic Arts, and Aegis Animator ($140) from Island Graphics and Aegis Development.

Electronic Arts attached themselves to the Amiga Corporation right from the word go, so it's to be expected that Deluxe Paint should be one of the front-runners. Put simply, Deluxe Paint is a painting program. More than that, it's a program that can turn a non-artist (me, for instance) into a passable impression of an artist. It's also horribly addictive. The program allows you to work in any of the standard graphics modes, though the 640x400 mode is inadvisable because of the interlace flicker.

By pulling down a menu to select colour control, you can make up your own palette of 32 paints by adjusting the red, green, and blue hues. Available brushes include a good variety of sizes, but you can also use a spray nozzle for air-brush effects. Most wonderful of all is the facility that allows you to define any part of a picture as a brush and stretch, colour, and shape it accordingly. So, if you want to paint with King Tutankhamen's nose, no problem. And with the development of cheap, ink-jet, full colour printers, it's even possible to make hard copies of your masterpiece to hand out to adoring techno-art groupies.

Aegis Animator also incorporates a paint system - Aegis Images - that provides very similar features to Deluxe Paint. But as its title suggests, Aegis Animator is designed primarily for the purpose of putting together animated sequences.

Typically, you might start off by creating a backdrop with Images (a lunar landscape, for instance) or by using a low-resolution digitised image. This is stored on disk, and you can then start building up the various elements to be animated. These could be jets of flame, the dust thrown up when the Eagle has landed, or whatever else your imagination and artistic flair might conjure up.

Selecting the storyboard from a pull-down menu allows you to define how the various elements fit together in sequence, edit the images using cut, splice, and paste functions, move objects around the screen, and set the speed of the animation.

If you want to see what Deluxe Paint and Aegis Animator are really capable of in expert hands, you could always take a trip to Philadelphia's Veterans Stadium, where it's reported that baseball fans are being wowed with Amiga graphics on a 42-footwide Panavision scoreboard.

"Unless someone can reprogram the output filters so that they cut off at a more reasonable level than 7.5kHz, the Amiga is doomed to emulating lacklustre Spectrum and CBM64 samplers."

So, if the Amiga's sound is good and the graphics are excellent, then there's clearly scope for software that combines both. One of the most eagerly awaited packages is the Deluxe Video Construction Set from Electronic Arts. Not only should this provide animation that's up to the pro speed of 30 frames/sec, but it also claims to allow the addition of music and sound effects, which can then be synchronised to the action with a sort of pseudo-SMPTE time code. The whole lot can then be recorded onto a VCR for dubbing and playback.

As I see it, the nice thing about this sort of combination software is that it crosses any conceptual boundary between the musical and visual arts. There are a great many musicians who'd love to integrate graphics with their music, but hitherto, they've had to find both a computer expert and a sympathetic artist in order to achieve any sort of realistic synthesis.

I don't pretend that the Amiga has actually gone quite that far, but it's certainly well on the way to being an exciting creative tool, and must be a foretaste of the future.

SUMMING UP IS RARELY EASY, and never less so than in the case of the Amiga. There are features that I love about the machine, and there are others that make me hopping mad.

If the Amiga was priced £475 cheaper, it'd be in direct competition with the Atari 1040ST, and there'd be no question about which machine was the better buy. But at £1475 plus VAT for the 512K version with a single disk drive, the Amiga is in an unfortunate no-man's land between low-price business machines and high-price home micros.

In the States, at least, much has been made (by Commodore mainly) of the Amiga's IBM PC compatibility. And while it's true that $199 or thereabouts will buy the US Amiga owner a package consisting of an extra 5.25" disk drive and some IBM PC emulation software called Transformer, total compatibility is an illusion. For a start, the only programs that will run are text-based ones like Lotus 1-2-3 and Wordstar. And once you've got them, they run so slowly it makes a mockery of using a powerful 68000-based machine for the purpose.

From the UK point of view, it's all academic anyway, since Transformer isn't being released here. Commodore's alternative route to IBM PC compatibility is a hardware add-on called Sidecar. Virtually an IBM PC/XT in itself, with an 8088 processor and 256K RAM, this bolts onto the side of the Amiga and enables any IBM PC software to be run at the same time as Amiga software. That's a great idea, but at a price that's quoted as 'substantially under $1000', I wonder whether Commodore can really count on people buying Sidecar, given that IBM PC/XT clones have already broken through the psychological barrier of £500, and Amstrad are poised to do battle for even less come the September launch of their IBM PC compatible.

And then, of course, there are the basic hardware problems of the Amiga. Commodore UK have stressed that they see the Amiga selling to the business and specialised market areas, eg. music and graphics. But even though the latter are the Amiga's strength, they're also the areas which, paradoxically, show up the Amiga's hardware shortcomings.

Unless someone can find a way of reprogramming the output filters so that they cut off at a more reasonable level than 7.5kHz, the basic sound side of the Amiga is doomed to emulating the lacklustre samplers that have been doing the rounds of the Spectrum and Commodore 64 circuits recently. Depending on what you read, the to-be-released Amiga 2 may correct that bandwidth deficiency, but the 50,000 or so current Amiga owners are hardly going to thank Commodore for correcting a limitation so late in the day.

If the Amiga is to break into the business market, then its graphics presentation has got to equal the competition. Apple Macintosh-quality monochrome graphics are so standard now that they're what people are expecting 16-bit, 68000-based micros to look like. Slavish copying is hardly a good thing, but if the Amiga could produce monochrome screens that looked like the Digidesign software for the Macintosh, or the Steinberg Research Pro-24 MIDI sequencer for the Atari, I wouldn't be one to complain. But because of the ridiculous flicker in the Amiga's 640x400 interlaced mode, the highest usable resolution is 640 X 200, which means the clarity of the Macintosh (512 x 342) or ST (640 x 400) monochrome screens is totally out of the question.

To add insult to injury, Commodore's own future as a company seems distinctly shaky, a position that's hardly helped by the prophets of doom and gloom who continue to take vicarious pleasure in predicting its imminent collapse. Whatever happens, though, it seems certain that the widening Amiga user base in the US will continue to be supported. Whether or not the Amiga 2 ever materialises is more open to doubt. My gut feeling is that the prohibitive cost of updating all the custom chips in the Amiga will prevent the Amiga 2 from being an earth-shattering improvement on the current model, anyway. What I guess will happen is that third-party companies will work to extend the Amiga's open architecture with upgrades. But judging by current prices being charged for samplers, extra RAM, and hard disks, it's also a fair bet that enhancements will come at a price.

The final complicating factor comes down to the activities of the competition. Rumours are circulating on US bulletin boards of a new Apple IIx 16-bit computer that comes complete with a 32-channel sound chip. Interesting, obviously, but I'll believe it when I see it.

A more immediate contender is Atari. Under the bullish direction of Jack Tramiel, Atari have been transformed from a mid-market games computer company into an aggressive manufacturer of cheap but powerful 16-bit personal computers. My current hostility to the ST series is based on their appalling record of reliability (as discovered only too well by E&MM's editorial staff), a ridiculous design of key-top that turns a competent typist into a quivering wreck and which gives a new meaning to the term 'writer's block', and a vintage sound chip that will probably keep JS Bach turning over in his grave for the rest of eternity, poor fellow.

However, the next few months may well oblige me to change my tune. Not only is the new ST machine reputed to use the very powerful, 32-bit 68020 processor, with 2Mbyte of RAM as standard, but it's also kitted out with an Amiga-type blitter chip and a rather more classy sound chip. Whether this turns out to be quite like the Amy sound chip (64 oscillator channels with 96dB signal-to-noise resolution) originally intended for the ST series is anyone's guess, but the few advance speculations I've gleaned are certainly enough to make me think seriously about changing my allegiance.

It's certainly an encouraging sign of the times that computer manufacturers are at long last putting music on the top of the list of hardware priorities, but let's hope that they don't forget the owners of last year's models - the Amiga included.

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Publisher: Electronics & Music Maker - Music Maker Publications (UK), Future Publishing.

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Electronics & Music Maker - Aug 1986

Scanned by: Stewart Lawler



Gear in this article:

Computer > Commodore > Amiga

Feature by David Ellis

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