ZON X FOR SPECTRUM

Bi-Pak has now made the ZON X-81 sound box available for the Spectrum as well as the ZX-81. It contains an 8912 three-channel sound chip with a powerful amplifier, loudspeaker and volume control in a 6in. x 3in. x 2in. black box. Everything is powered from the computer and some complicated sounds can be generated which will repeat without the aid of the computer.

As the device is I/O-mapped it requires machine code on the ZX-81 but an ingenious method of making it compatible with other REM-located machine code makes it easy. The Spectrum must use an additional board which contains a 3.5MHz oscillator to stabilise the frequency used. That is about 2in. long and fits between the Spectrum and the ZON 81.

One problem with the decoding makes it incompatible with the Microdrive and RS232 intended for the Spectrum as it uses A4, which Sinclair has already declared will be used by its devices. Apart from that it works well on both machines, providing a cheap and easy alternative to the BEEP command.

Bi-Pack sells the ZON X for £25.95 and the Spectrum board for £6.80. Bi-Pak is at PO Box 6, 63a High Street, Ware, Herts. Tel: 0920 3182.

ADDING ON YOUR SPECTRUM

Our review team take a brief look at some of the hardware add-ons fir the ZX Spectrum.

Now that the ZX Spectrum has well and truly established itself on the micro market, it is amply supported by a wealth of hardware add-ons. Most of these peripheral devices have been manufactured by the people who supported the ZX81, but just as the Spectrum has attracted new users with its prowess, so too has it attracted a new following from the add-on manufacturers.

In this brief guide, we have not tried to cover all the devices currently available on the market but rather give you a flavour of the technology you can add on to your Spectrum. As joysticks are an obvious favourite, these have been covered in some detail whereas RAM packs are fairly standard and so have only been briefly touched on. Also included in this section area number of quite specialised add-ons like sound units and a digital tracer.

If you own a Spectrum, you will no doubt have begun to realise the potential you hold in your hands. Over the next few pages you will hopefully see further applications for you and your computer to explore.

Originally designed for the ZX81, Bi-Pak have now released an adaptor so that the ZONX-81 can now be utilised with the Spectrum.

Self-contained in a strong plastic box, the unit easily plugs into the rear of the Spectrum forming a good connection. There is a manual control for the volume, the sound produced being clear and within a reasonable volume range.

Using the unit, via simple BASIC commands included within a piece of software, a wide range of sound effects can be produced by the three channel plus noise chip housed within the unit. Thus, depending on various statements within a program, the pitches and volumes of three channels and overall attack/decay envelope can be manipulated. And what that means is that you can get quite realistic sound of explosions, helicopters, bells, etc.

There is an interface at the rear of the device which means that you could add other devices on the back of the Spectrum at the same time as your ZONX.

Complete with a very comprehensive manual with tried and tested software examples, the ZOISIX is priced at £32.75. For more information contact Bi-Pak Semiconductors, The Makings, 63A High Street, Ware, Herts SG12 9AG.