The number of introductory books to the Spectrum is legion and introductions to Spectrum machine code are not far behind, but books on machine code techniques for the more experienced programmer are much thinner on the ground. David Laine's Machine Code Applications For The ZX Spectrum is intended to fill this gap in the market and presents the advanced programmer with a number of useful routines.

Though it is not for the beginner, the book kicks off by explaining how you should approach machine code, and gives some timely tips on programming techniques.

Next is a quick turn through the instruction codes, number representation and addressing, and straight into a few listings.

Once you're further into the book and the machine, Mr Laine presents routines to handle floating point numbers, output to the screen, animated graphics and Basic block delete.

Of course, there may not be much more around yet, but by the time you've finished reading, you should really be writing it yourself, right?

John Lettice