Advanced Spectrum Machine Language

Your Spectrum

Tony Samuels

PHEW - WHAT A SCORCHER! Some time back, Melbourne House published Super Charge Your Spectrum - in effect, a heady selection of ready-to-run machine code routines (multi-directional scrolls, useful sound effects, program re-numbering utilities and so on). Now from the same stable (and author) comes Advanced Spectrum Machine Language, a book containing far higher grade routines that cover areas of the 48K Spectrum that have never before been explored. Right from the word go, author David Webb boasts things like animated loading screens, all you never knew about interrupts, the lowdown on pixel animation techniques, an interrupt-driven print processor with full screen horizon generator, and true Hires colour; all in all, pretty impressive for a mere book. And what's more, most of it is actually as good as it sounds; the only exception for me was that animated loading screens turned out to be the Manic Miner kind - as opposed to real animated characters that move across the screen while a program loads. Several chapters of the book turn attention to the design and development of a sprite routine which is absolutely flicker-free. In fact, though this is probably the only part of the book to fall below the standard of the best arcade games; all the same, you still end up with a sprite routine worth having. At times, David Webb tends to babble on a bit, but he always gets there in the end. Overall, Advanced Spectrum Machine Language is clear and well thought out, and it's also excellent reading for the most experienced of programmers. It's probably the best Speccy book of the year so far and, without doubt, receives the YS seal of approval.