ZX Spectrum Expansion System

Your Computer

STORAGE AND RETRIEVAL OF PROGRAMS Spectrum owners are being fated with an ever increasing number of alternatives to the humble cassette. The three devices here all offer fast program storage at a reasonable price. The Sinclair Microdrive has been around for over a year now and has undergone various attempts to improve its reliability. It has now appeared in a pack with the interface and some software called the ZX Expansion System priced at £100. The interface also has an RS-232 port and a network. The operating system is simple to use allowing programs and data to be saved on the Microdrive. Data is stored by opening a channel and then writing data to it. One drawback with the system is that some games cannot run with the interface attached, as the operating system will grab some of the Ram. The software comprises of the popular Tasword 2 word processor, a database, Ant Attack, Games Designer and a spare blank cartridge. The number of Microdrives can be linked up, each further drive costing £50. The cartridges cost £5 each and hold about 80K. Along very much the same lines as the Microdrive comes the Wafadrive from Rototronics. The unit has two drives, RS-232 and Centronics ports and comes with two wafers and a word processor for £130. Although noticeably slower than the Microdrive, this unit scores in several areas. It is said to be more reliable than the Microdrive and the operating system is more informative. The directory command gives more than a list of files like the Microdrive. The formatting command also gives a full report of the state of the wafer. Unlike the Microdrive, it does not grab any workspace until initialised with a simple New* command. Also, should you wish to back-up a file from one drive to the other, you can do so without upsetting the contents of the memory. It saves data in a similar manner to the Microdrive. In an attempt to make up for the slower speed, the wafers come in three sizes: 16, 64 and 128K. This obviously means that the average access time on the 16K Wafer will be lower. Thus you could load the main program from a 64K wafer in drive one, and have the data you wish to continually read and write on a 16K wafer in drive in two. The wafers are also cheaper at under £4 each. Moving away from fast tapes to discs, the Beta Disk Interface from Technology Transfer allows you to interface the multitude of disk drives available for the BBC to your Spectrum. One point to bare in mind though, if the drive uses the Beeb's power source, you will need to buy a power supply. Having got over that hurdle, the system is fast, user friendly, and of course, at £1.50, the discs are much cheaper than wafers or cartridges. The DOS has all the usual commands you'd expect and you can switch it in and out as needed. It even has a disc password system to keep your software from prying eyes. You also get a free utility disc with the system with the various utilities they didn't have room for in the interface's Rom. The interface can be used with single or double density, single or double sided drives, and up to four can be connected to the one interface. The system's major limitation at the moment in that data cannot be loaded or saved on disc, but Technology Transfer promise a new Rom in the new year and will upgrade existing units. The interface costs £97.25 for single density and £109.25 for double density. Which of these systems you go for really depends on your priorities. Although the Sinclair product is the cheapest, the cost of the cartridges makes it less competitive. The cheapest medium of all, are the discs at £1.50 each. If you've got a collection of 40 discs or so, then the disc drive will have paid off.