If you've always thought that a monitor was an alternative to the family TV, you may think that a machine code monitor would be a fast version. In fact, Starmon is a piece of software stored on a micro chip. This type of software is sometimes called firmware and to be able to use it, you will need a sideways ROM card to plug into the expansion port at the back of your Electron.

A machine code monitor program like Starmon enables you to look at the contents of the micro's memory, both the 32k of RAM and the other 32k of ROM. The program is very easily loaded. Just type *ST and it's there - instantly.

Once loaded, you may well wonder what to do with it. Well, the clever part of Starmon is that it uses the memory normally occupied by Basic, so running Starmon will not interfere with the program in memory.

It is easily possible to study any program - even those unlistable ones. Of course, you do not get a Basic listing. It is the contents of memory you see, but Starmon will do its best for you. The contents of memory can be displayed in decimal, hexadecimal, binary or even octal. In addition, if Starmon thinks it detects an ASCII character it will print that. It can also disassemble code - that is, it produces a listing in assembly language.

This all sound very fearsome, but if you are a beginner to this kind of thing, don't be put off because you can quickly learn some skills. For example it is very easy to alter the contents of memory without spoiling the program. I have personalised halls of fame so that they load with my name.

For the advanced user, Starmon is a very full program. With it you can search memory for bytes or strings, or move chunks of code around from one area of memory to another. You can block fill memory, write directly to memory locations or alter the 6502 registers. There are also facilities to single step through programs, which can greatly help with debugging, or allow you to learn what machine code instructions do. It is also possible to dump Starmon screens to a printer for future reference.

Starmon comes with a well written 42 page booklet, which makes the program easy to use. This whole package would be very useful to anybody keen to program, or even just dabble in machine code. It is a thoroughly professional piece of firmware.

Rog Frost