Practical Spectrum Machine Code Programming

Your Spectrum

Tony Samuels

There are two fundamental approaches to the teaching of machine code. The first is to assume the reader knows nothing about computers at all, so everything kicks off from the very beginning; the other makes use of reference to Basic, as a way of putting over some idea of the concept behind the instruction being taught. Practical Machine Code Programming falls into the latter camp - a sort of 'soft' approach for those who already have a fair knowledge of Basic. Steve Webb opens his account with a description of what machine code is and how numbers are stored in memory and follows that with the de rigeur rundown of the 'ins and outs' of binary and hexadecimal. The first few chapters are obviously designed to teach the bare essentials of machine code programming. Things then get Spectrum specific, with descriptions of how the display and attribute memory is arranged, and also how you read the keyboard and create simple sound effects. But nowhere in the book is there any mention of assemblers or assembly language. The book now switches track completely and starts to describe the relevant processes that lie behind a few simple machine code games. Each routine is reasonably well described and accompanied by a nonstandard flowchart. And, although the programs are written in a rather non-efficient way, they are fairly easy to follow. As usual there's a selection of standard pixel and attribute scrolling routines. I can't say that overall the ideas in the book are my personal favourites... certainly the volume won't be one that comes high on my recommended reading list. On the other hand, at £3.95 what have you got to lose?

Read it at Your Spectrum Unofficial Archive