How often have you been playing a computer game and had to abandon it due to a pressing engagement? The opportunity to 'freeze' a program at any instant would provide an ideal solution to such frustrations. Or maybe some other interruption takes you away from the machine longer than a few minutes, and just as you had cranked up your best score yet, and a host of extra lives too! Wouldn't it be nice to have the facility to save the game away on disc or tape, and then reload it later and continue exactly where you left off?

Well, Master owners can now do just that with Care Electronics' Smart Cartridge, consisting of a holder ready fitted with Care Electronics' EPROM. This 'black box' plugs into one of the Master's cartridge ports and enables you to perform this handy trick and quite a few others too.

On top of the cartridge is a small red button, and when pressed a number of different tasks can be initiated: These tasks are chosen from an on-screen menu and relevant details of the tasks chosen are then stored in the cartridge's own RAM.

You can choose to save the contents of the Master's normal screen RAM, the Shadow RAM or the entire RAM, either straight to disc or to banks 4 & 5 of sideways RAM for subsequent saving to disc. Alternatively, you could opt to temporarily freeze the current program, send a screen dump to an Epson-compatible printer, call a Help file, poke a byte into any memory address, call a machine code program resident in memory or execute an operating system star command.

The ability to issue an OS command from within a program is very exciting. For example, you could exit from a program, examine memory by calling a machine code monitor such as Beebug's Exmon and then alter the contents of an address and return to the program.

This feature of the cartridge is extremely powerful, but there are also potential dangers and abuses. Not least of these is that it makes the pirating of software much easier. Care Electronics acknowledge this with a statement in their literature condemning this practice, which is illegal.

In the main, using the cartridge should be straightforward. I say should be, as the documentation supplied with it is really awful and leaves you much to work out for yourself. In particular, two features of the cartridge that appear on the menu screen are not documented at all (and calls to both suppliers and manufacturers have so far failed to determine what these extra functions do). Once you have got to grips with the various features of the cartridge though, all works well. The saving and reloading of programs mostly worked fine in practice, but there were a few games I tried that would not work properly on reloading.

This is a most intriguing and powerful piece of kit. It has so many possibilities that many Master owners I am sure would find it a great asset in one way or another.

I would suggest, however, that Care Electronics consider lowering the price of the Smart Cartridge. It is, I feel, rather expensive at present. Also, they should most certainly supply decent documentation. The four sheets of computer printout supplied at present are badly written and quite inadequate.