80-Bus News

Three Nascom 2 computers were in use in our primary school. The stage was reached where they were ready to go into general school use as opposed to usage in the computer clubs. With a dozen Maths and English games written we needed an operating system that would make the entry of these programs truly child’s play. A five year old (or even his teacher!) must be able to load the game that is needed. Disks would be ideal but we could not afford three sets of drives. Our computers will be too widespread and too mobile even for mains power and a networking system would be hopelessly impractical. The Hobbit unit reviewed here meets all our requirements so completely, and its use has already proved so succesful that it was decided to write this review. I have not used the rival decks produced in Scotland so can offer no comparisons with this Welsh unit. Being English I can claim neutrality.

If you are thinking of instant retrieval of programs then forget the Hobbit. A new cassette has to be formatted with certain timing information (F command : 240 seconds). It is best to format both sides while you are at it. It is then simplicity itself to write programs to tape, whether they be BASIC, FORTH, PASCAL, or ZEAP. I did feel the instructions were a little incomplete here, but I managed so they can’t be too bad. I do not know if Naspen can be filed but if one of the Hobbit routines is not suitable then it would be easy to write one that is. I do feel this to be a major omission from the Hobbit manual, especially as Naspen will be our next purchase! The important thing is the ease of finding the program again. The tape with the program on it has to be mounted (M command : 80 seconds). The names of the programs on the tape can then be displayed (N command : instant). I do not like the standard display format of five names, followed by the next five on ENTER,.....up to 69 files. Nor do I like only six character names, but given this it should have been possible to display all file names on one screen. I am hoping to alter this on our systems. The chosen program is loaded into memory and runs or executes automatically. (R command : 6 seconds to 68 seconds).

There are 56 KBytes of storage on each side and we are able to record about six of our school programs in that. If a cassette has been mounted for a class to use it averages about 40 seconds to run one of its files. If a new cassette is needed it takes about 230 seconds. Reliability is 100 per cent all the time and appears to me to better the Commodore and Research Machines disks, both of which have given me problems. I doubt if the simple Phillips mechanism will ever need servicing.

The unit arrives ready built, well built, without plugs and uncased. It is delightfully compact and is the first piece of computer hardware that has brought forth, “Oh isn’t it sweet!” from wife and daughter instead of the usual. “How much did that cost?” It uses mini-cassettes, much smaller than audio cassettes, and two were supplied with our two drives. The whole cube shaped unit would fit easily into a Nascom 3 case, or a Kenilworth. Ours mount just above the keyboard. They may be mounted horizontally, vertically or any angle inbetween. Ours even worked upside-down. Connections are 12 volts (120 mA), 5 volts (10 mA) and Earth. Eight Data/​Control lines go to port A on the Nascom, the big 26 pin plug sometimes called PL4, the one with control port 6 and data port 4.

Any fool could follow the Hobbit directions thus far. Not so easy is setting up the two 2708 EPROMS. As usual all the information is in the Nascom manual but it does take some reading. These EPROMS are normally supplied to work at D000 in the memory map. So connect pins 4, 6 and 7 to pins 10 and 11 on LKS1 and switches 7 and 8 on LSW1 up or closed. This will make the eight memory sockets on the Nascom board decode as one 8 KByte block from C000 to DFFF. The