A Ceefax and Teletext adaptor for the BBC Micro is tested out by Piers Letcher

Acorn's Teletext system allows you to access Ceefax and Teletext services from your BBC Micro. You can also interact with the system to download information and programs.

The Teletext adaptor is expensive at £225, especially since it was originally advertised at £115.

The Teletext system arrives surrounded by foam, and with a plug. The heart of the system is the Teletext adaptor itself. This is a cream box, the same height and length as the BBC, but about one third of the width. Also with the system comes the Telerom, a manual and a slip of paper that goes under the ruler on the BBC.

In the event of you not having an operating system above 0.1, a voucher allows you to get the Telerom fitted at the same time by your dealer.

From the adaptor run two leads, the power cable and a 34-way connector that plugs into the 1MHz bus. At the back of the adaptor are four little red tuning wheels.

First you must have the Telerom fitted to your BBC. This involves taking the casing and keyboard off, and slotting it into one of the free slots. A dealer will do this for you, and you can use the voucher provided. The pins on the ROM I fitted were in fairly poor repair, bent and fatigued. However it did finally slot into IC88.

Once the ROM is fitted you can do a *HELP to check the BBC is happy with it.

Next you need to connect the leads together. The adaptor plugs into the 1MHz bus and the mains, and the TV aerial plugs into its back. The BBC is connected up as normal.

Now the adaptor needs to be tuned in. This is done by following a carefully detailed procedure in the manual. A bar chart marked 0-100% gives you the strength of the signal, and twiddling the appropriate red wheel tunes you into a channel.

This incredibly tedious task can take hours. One problem is that all four channels can be received on each of the adaptor's knobs. If the system has been set up as shown in the manual, you find that after several turns your fingers ache since the knobs are on the opposite side of the adaptor to you.

The travel on the knobs is extensive, but the delicacy needed to tune accurately is enormous. This operation requires a lot of patience and an element of skill, and is a most frustrating task.

Once tuned, cellotape the wheels in position - it's something you'd never want to do again!

The pictures are exactly what you'd expect from Ceefax - clear and colourful, with lumpy graphics.

Thankfully the manual is thorough and precise, with plenty of examples and tables, helping considerably to explain the adaptor's complexity.

The system is easy to use, and it's entertaining to page through the wealth of information available on the airwaves.

Some problems were found with the TFS ROM fitted, but this may have been due to the condition of the one reviewed. In particular there were problems with the DFS and with loading and saving programs while the TFS was present.

The system allows you to operate in three modes. The first, Terminal Mode, is the most useful and is the main reason for having the Teletext system. It makes your BBC a mildly intelligent terminal rather than a computer in its own right.

Telesoft mode shows the new ROM you've fitted is a filing system, and allows you to use it in a read-only sense.

Assembler mode is also available, but the uses for it are not obvious. From it you can control Teletext via machine code.

Apart from the difficulty of getting the system to work correctly, the Teletext system proves an intriguing device. It is sad you cannot superimpose the teletext broadcasts on a TV picture since one of the best features is subtitles on TV programs.

But there is still the question, who will find this useful?! There are programs available which can be downloaded into your BBC - but the same programs can be accessed using a suitable TV, and then typed in. The Teletext-compatible TV allows you to superimpose the broadcasts onto TV programs.

As the price of other peripherals (especially printers and disk drives) falls, £225 seems very expensive for what boils down to little more than you can get from a Teletext receiving TV.