System & Third-party Software For Sound Synthesis; PCI

Martin Russ considers some ways of realising sound synthesis on your Mac using system or third‑party software, and concludes his look at the PCI buss.

Although the Macintosh has had the capability to use software to synthesize sounds for many years, it is only comparatively recently that this has advanced beyond the 'Bleep and Booster' school of gritty computer audio. For example, QuickTime 2.0 incorporates a set of sounds which have partial GM compatibility. There have been one or two mentions in SOS on this topic: see Apple Notes April 1995 and September 1994, and Paul Lehrman's excellent article on Software Synthesis in SOS October 1995. Two recent software releases bring this subject into focus again.

The new QuickTime Music OMS driver lets you use the QuickTime Musical Instruments (new versions of which should now be available as part of QuickTime 2.1) in any OMS‑compatible application, without the need for any external MIDI instruments. Instead, placing the QuickTime Music OMS driver (see picture, right) into the OMS folder (inside the Mac's System Folder) provides 16 new instruments (named 'QuickTime‑1' to 'QuickTime‑16'). The driver appears as an Interface icon called 'QuickTime Music' in the OMS Studio Setup document — just like the IAC Driver, which is used to allow intercommunications between music applications. The only hiccup was that I needed to reboot my Mac after installing QuickTime, and the driver before the Studio Setup would recognise the new interface driver.

Setting it up involves setting the pitch bend sensitivity (0‑24 semitones) and choosing the drum kit (see picture, right). If you choose the Rock drum kit, then the QuickTime Music synthesizer assigns the drums to Channel 10 as per General MIDI, but if you don't choose the Rock Drum, then MIDI channel 10 can be used as a normal synthesizer channel. At the cost of occupying anything up to 1Mb of system RAM memory, the QuickTime Musical Instruments extension and the QuickTime Music OMS driver give partial General MIDI playback from a stand‑alone Macintosh. Contact TSC on 0171 258 3454 for more information on obtaining the QuickTime Music OMS driver, OMS, or any Opcode product.

Cyberpunk Rock

InVision's CyberSynth takes the idea of a software‑only GM synthesizer several stages further. For an introductory price of only US$199, the CyberSynth CD‑ROM provides the synthesizer software and nearly 50Mb of 16‑bit samples. They've been produced using a variety of synthesis techniques: both analogue and digital synthesis, as well as physical modelling.

InVision are apparently working on a professional‑level software synthesizer, and this may well have provided some of the samples. They also produce sample CD‑ROMs (the evocatively‑named 40oz. of Phat Slammin' Hip Hop springs to mind), and their sound libraries are probably where the majority of the 500 samples which are provided on the CD‑ROM come from. Additional CD‑ROMs are, as always these days, 'under development'.

CyberSynth has broad compatibility: OMS, FreeMIDI, GM/GS, MIDI Manager, Sound Manager, QT and more acronyms are all catered for. Hardware‑wise, you will need a 68040 or PowerPC (native) processor with 8Mb of RAM and at least 6Mb of hard disk space. Software‑wise, the polyphony depends on the processing power available: 128 notes on a PowerMac 9500, down to 24 notes on more modest machines. Apple Notes will try to bring you a user report just as soon as we can test CyberSynth out.

All Aboard The PCI bus

After last month's look at PDS, SCSI and NuBus, this month's topic is the PCI buss. Here's some questions and answers.

I started to talk about the Peripheral Component Interconnect (PCI) buss in the November 1995 Apple Notes. It provides a platform‑independent solution to the problems of producing add‑on cards for computers — which brings us to the obvious question:

Will a PCI card work in my PowerMac?

The answer currently seems to be that provided that a PCI card manufacturer implements the PCI 2.0 specification, complies with the Open Firmware standard (IEEE 1275) for booting PCI cards in an operating system‑independent environment, and provides a Mac Operating System‑specific driver, then that PCI card should work in a PCI‑equipped Macintosh.

If that sounds like quite a few caveats, then the usual advice of 'try before you buy' applies — and as with any change of technology, test thoroughly in your specific setup, not one that is merely similar to it! Even so, given the wide acceptance of PCI outside of the IBM PC‑compatible world, PCI card manufacturers should rapidly catch on to the fact that they have a larger potential market of PowerMac and Workstations like Dec Alphas, and will ensure that they are compatible. Most IBM PC‑compatibles already seem to implement PCI 2.0, for example.

What sort of PCI cards will be produced?

Because the PCI buss is intimately connected with the main buss inside the computer, it can provide a number of expansion capabilities that take advantage of the high‑speed access that is available. Graphics accelerators and network cards are probably going to be the most common uses, but you can expect some to be Mac‑specific, like DOS/Windows compatibility cards with 486 or Pentium processors. Mac music‑related cards will include PCI‑to‑Nubus adapters, as well as PCI‑to‑SCSI adaptors intended for driving RAID disk arrays. Companies like Digidesign are now producing PCI cards, often with a NuBus‑to‑PCI exchange scheme.

What about the future of PCI?

In the near future, PCI 2.1 should improve the data transfer speed for some real‑time applications — particularly video editing and perhaps audio direct‑to‑disk. In the longer term, PCI 3.0 should double the throughput of data to over 200Mbits per second — but the exact method which will be used to achieve this is still uncertain. The current 33MHz clock could be increased to 66MHz, or the buss could be widened from the current 32 bits to 64 bits. There are pros and cons to each approach, and the PCI 3.0 specification is not due out until 1997 — so watch this space.

What about 3.3 volt PCI cards?

After many years using 5 volts as the main logic power supply voltage, the ongoing reductions in chip size and power requirements, and increases in speed are forcing the computer industry to lower the supply voltage. 3.3V chips are already being used in many applications: some Pentiums and PowerPC chips use 3.3 or 3.6V supplies, and there are many support chips that use 3.3V. If PCI 3.0 uses a 66MHz clock, then this will force the use of 3.3V. Long‑term, the future seems to be 3.3V for almost all computing hardware.