OctaMED Technique & ARexx

Paul Overaa gives you the latest on the Amiga scene...

With Amiga machines now seemingly safely back into the shops, there are doubtless plenty of existing Amiga users who are, both privately and publicly, breathing huge sighs of relief. It's certainly true that the 'worst case' scenario that could have been brought about by the last eighteen months or so, namely the demise of the Amiga, is not going to happen. With the Amiga Magic software bundle including such things as Wordsworth the word‑processor, Digita's Organiser and Datastore programs, the Turbo Calc spreadsheet, Cloanto's Personal Paint, Almathera's Photogenics graphics packages, and, of course, some games, the Amiga Techologies new £399 A1200‑based pack is already creating some well‑deserved interest.

Those who fork out another £100 for a 170Mb hard disk‑based machine will also get the Scala MM300 multimedia package as well. Everyone in both computer retailing and software/hardware production is obviously hoping for great things to happen, with some even trying to push things along in this respect. Silica (tel: 0181 309 1111), for example, are currently throwing in an additional set of software, including the games Chaos Engine, Syndicate, Pinball Fantasies, and Nick Faldo Championship Golf!

Of course, part of the Amiga's future, like it or not, is going to be dictated by the games‑playing fraternity, and Sony's new PlayStation is obviously at the forefront of every games‑player's mind at the moment. Sony's massive PlayStation advertising campaign is going to get not only adult game players, but kids and their parents into the computer stores over Christmas, and this might actually work to the Amiga's advantage. Once a look at the shelves tells them that the Amiga is back, then all sorts of things could happen. Irrespective of the fact that the Sony PlayStation is good piece of equipment, plenty of parents may well prefer to buy little Johnny an affordable home computer, rather than a pure games machine. Don't knock it — what needs to happen now more than anything is that Amiga Technologies sell machines. This, and this alone, will safeguard the continued future of the Amiga.

Whilst some of the smaller Amiga sequencers, such as Software Technology's Sequencer One Plus, will run perfectly happily on floppy disk‑based machines, the Amiga's Workbench‑based operating system has really reached the stage where a hard disk is almost essential. This doesn't affect games players much, but I would advise anyone thinking of getting one of the new Amigas, either for MIDI‑based music sequencing, or for any other serious applications come to that, to pay the extra £100 and get a hard disk‑based machine right from the start. The heavyweight sequencing packages, like Blue Ribbon's Bars & Pipes Professional for example, are also a nightmare to use on 'floppy only'‑based machines!

Octamed Technique

A new tutorial guide to using OctaMED and OctaMED Pro has just been released by Andy Soar. The guide itself, aimed primarily at Amiga users who have a working knowledge of OctaMED or OctaMED Pro, is relatively short, but well planned, and includes advice on creating reverb, adding echo and chorus effects to your music, using loops and breaks, and even time stretching. An examples disk is also provided, which loads straight into OctaMED. The freely‑distributable OctaMEDPlayer (version 6) program is also included on the disk.

The OctaMED Technique guide, incidentally, is not intended to replace the manual, it is simply meant to supplement it by illustrating particular OctaMED usage techniques. The emphasis is essentially practical in nature, hence everything that's dealt with in the printed guide has an associated example on disk, which you can both listen to and examine by loading into OctaMED itself. The guide also includes material such as tips on digitising, and there are even some brief notes on sampling and copyright (handy for budding songwriters!).

Andy Soar, in case you've not heard the name before, has been around the Amiga music scene for quite a while. Amongst other things, he has composed the music for games like Bump & Burn, Ruffian, and Bloodnet using OctaMED and, needless to say, this means that he has a pretty good idea how to get the best from the package. The UK Price is £5.50, and this includes postage and packing (£6.50 + IRC rest of world). For further details telephone: 01476 65407.

The MIDI‑Arexx Connection

I've had a couple of letters recently from readers asking how they can transmit and receive MIDI information using ARexx (the inter‑process scripting/communications language that now comes as an integral part of the Amiga's operating system). The first step is to configure the Amiga's serial device for MIDI, and this means using the serial Preferences editor to select 8 bits+1 stop bit transmission at a Baud rate of 31250, with no handshaking and no parity. Having selected and saved these settings, you'll be ready to start.

AmigaDOS provides two high‑level serial device handlers that can be easily used from ARexx — AUX: provides unbuffered serial I/O, and SER: provides a stream‑oriented, buffered interface. I tend to use AUX: for transmitting MIDI data and SER: for collecting it (since incoming MIDI information could otherwise be lost). If, incidentally, you want to use the AUX: handler, you must ensure that it is up and running — on new Amigas it's best to drag the AUX: icon from the Storage/DOSDrivers drawer to the WBStartup drawer so that it is always available from the time you boot your machine.

In both cases, these serial handler names are treated just like conventional disk files. To open the AUX: device, for example, we use this sort of script arrangement...

if Open(1,'AUX:','WRITE')) then

do

/* here we would do something! */

end

To transmit MIDI bytes, it's necessary to use the ARexx Writech() function. For example...

call Writech(1,message$)

would transmit all the bytes defined in the string called message$. If, for example, the variable message$ was defined as the two hex values C0 hex and 00 hex, then the above message would be a program change 1 message on MIDI channel 1. If, in fact, we now put all these ideas together, we'll end up with a short script that does indeed transmit just such a program change message...

/* midi_example.rexx */

if (Open(1,'AUX:','WRITE') then

do

message$='C0'x||'00'x

call Writech(1,message$)

call Close(1)

end

Well, that gives you a runable example and, as far as ARexx's MIDI connections go, there's not that much more to tell. The corresponding ARexx function used for reading incoming MIDI data is called Readch(), and this requires both a file handle and the number of bytes to be read. In this case, since you'd not normally know how much MIDI information was going to appear at the serial port, you'd need to loop‑read incoming MIDI data one byte at a time.

ARexx, of course, is an interpreted language, and as such, script execution is relatively slow, so it's certainly not an ideal language for complex MIDI programs. It is, however, perfectly capable of being used to knock up small diagnostic utilities, etc. Since ARexx is now given away freely to all Amiga users as part of the system software, there's absolutely nothing to loose by experimenting with some of these types of MIDI‑oriented ARexx scripts (other than a little of your time). Those of you who take an interest in MIDI SysEx message creation will find that this sort of practice is great for coming to terms with hexadecimal number conversion, and so on!