The Hobbit is a so-called "floppy tape" unit which plugs directly into the Beeb, providing program and data storage with some of the facilities of discs, but at a lower cost. The device actually stores programs digitally on Philips mini cassettes similar to the 3g-minute audio tapes used in some dictating machines. The tapes cost around £3.00 each, and will store about 60k bytes on each side.

The Hobbit plugs into the BBC user port (not present on a model A) via a twenty-way connector, while power is taken from the BBC's power out socket (not present on early Beeb power supplies), and so does not need mains voltage or a transformer. A second drive can be chained from the first and neither arrangement requires the disc interface or modification to the cassette interface. It is possible to switch from Hobbit to tape and vice versa by the commands *TAPE or *HOBBIT. Firmware is provided in the form of an EPROM. It will fit in any of the empty 28-pin sockets alongside the Basic and OS ROMs - if socket IC190 is vacant you only need to slip it in and move the link marked 18 over. If this seems too complicated, Ikon will do it for you for an additional £5.75.

The only other chore is formatting new tapes. This takes about three and a half minutes per side following the command *FORMAT NAME and is by far the slowest Hobbit function. A 100k disc takes around half a minute by contrast.

With the exception of the cassette eject button on the Hobbit the system control is from the keyboard. In other words fast forward, rewind and play/record are all looked after by the operating system. In Basic the Hobbit index is very helpful and the single command *CAT will display up to 68 eight-character file names (as against the ten of the cassette filing system, or the rather limited 7 of the disc system), each prefixed with a number. Data or programs can be LOADed or RUN from the index page by keying the number or name followed by f8 or f9, and sitting back.

Unwanted files can be deleted by *DELETE NAME - though data files need to be followed by: D, which is one of the many points not made in the first round of documentation. *RECOUP brings files back from the dead (if you have not already written a new file), while *KILL is by far the fastest command available and will wipe a whole tape in no time at all. You can also RENAME, COPY or APPEND (to each other) files.

The most important information not documented is the warning not to leave a tape in the drive at power on/off. If you do you may (as I did) corrupt a block which will inhibit LOADing the file back. Most BBC OS commands can be used, but not normally in abbreviated form: you have to use *CAT and not *. and you cannot interchange lower case with capitals in OS commands or file names. You can switch to Wordwise with *W. - but if you want to get back you need BASIC, as B. does not operate. Other undocumented items are the error messages such as CHECKSUM, HEADER, CLOSE FILES and SGN.

The read/write speed is 750 bytes/second as against the 150 of the cassette, and 11,509 of the disc. The actual speed improvement, over the cassette filing system, will depend on the sort of file that you are making: for instance there is a certain 'overhead' when it comes to making a file - the Hobbit has to find a place to write it and the fuller the tape is, the more it may have to hunt for a place to save it. Average access time is said to be 20 seconds with a maximum of 90 seconds. You must then add the time to save or load the program itself, at around one fifth of the time for loading from ordinary cassette. The disc system by contrast will save or load 20k bytes in just five secs. This includes access time.

The single Hobbit costs about four times more than an expensive tape recorder, which does not sound unreasonable. Comparisons with discs are perhaps less favourable. The Hobbit costs about the same as a 100k disc drive (as supplied by Microware for example - Acorn's own are more expensive), but the disc user must add the cost of the disc interface. However discs are £1 or £1.50 cheaper than the Hobbit cassettes, and this price differential will make serious inroads into the apparent relative economy of the Hobbit over a floppy disc.

Publisher: Ikon Computer Products, Kiln Lane, Laugharne, Carmarthen, Dyfed, Wales. Tel: (999421) 515. Cost: £155.25, Second drive: £138. Tested on O.S 1.2 with Wordwise. It is claimed that Hobbit will also work on OS 0.1.