Many Commodore 64 owners will eventually want to sample the delights of machine code, and will approach the shelves of their local bookshop for succour. Beyond Basic On Your Commodore 64 claims to be the book for the job. The rather slim volume of 144 pages on such a large subject immediately gave me cause for concern. My apprehension increased when 70 of the pages were devoted to a rather incomplete list of the 6502 instruction set, and nine appendices of dubious merit.

The first chapter starts with general memory structure, RAM, ROM, pages, etc. The author recommends that the reader visualises memory as an array of pigeon holes, a typical analogy, but no diagram is provided. In fact, there are very few diagrams throughout, and a picture can paint a thousand ASCII characters.

Logical operators are introduced but the examples are vague, and the usual truth tables for AND, OR, EOR are noticeably absent. Some other processor commands are briefly covered in chapter 3, unceremoniously followed by the previously mentioned instruction set. The list contains references to addressing modes which have yet to be covered, and gives no indication of cycle times or out of page effects.

A very short program includes some of the commands already covered. It is listed in HEX with the appropriate mnemonic alongside, together with some comments. The author suggests that is POKED into memory, unfortunately without any clear explanation of how to do it.

Addressing techniques are briefly mentioned but with the use of trivial examples. The sections on Binary Coded Decimal and floating point manipulation are glossed over.

Interrupts tantalisingly promise uses for the function keys, but the reader is only frustrated by incomplete information. Several substantial assembler listings attempt to help explain split screen and scrolling effects, but it is unlikely that the beginner will be able to incorporate the principles into his own programs.

I could go on, but it doesn't get better. Any any price this book would be too expensive, but £6.95 is extortionate. Leave this one of the shelf.