Title: A Practical Guide to
Machine Language
Programming on the
Timex/Sinclair
Author: David B. Wood
Pages: 250+ii (Softcover)
Machines: ZX80 & MicroAce w/ 8K ROM
ZX/TS (Usable w/ Spectrum
and TS2068)
From: SIRIUSWARE,
6 Turning Mill
Lexington, MA 02173
ISBN: 0-926848-00-3
Price: $14.95 + $1 P&H
I like this book. It’s well written, stays on point, applies directly to your ZX/TS, includes operable program listings and lets you learn painlessly.
Using only 16 chapters and 8 appendices, Dave takes you on a guided tour of the Z80 in Sinclair country, distinguishing the CPU properties from the system behavior with clarity and flair. Your tour guide is an expert whose practical experience includes writing the word processor “WORD*” on which this book is written. Appendix 4 contains Dave’s assembler, written in BASIC, for you to type in and use to try routines.
Appendix six catalogs the ROM routines into nine functional areas and then provides address, exit and entrance conditions, plus a concise operational description for each.
Other appendices collect widely available reference material and organize it for use with this book.
From the following list of chapter titles you get an insight to what’s covered:
1 Bridging the Gap
2 Locating Machine Code
3 Software Tools
4 Organization of Memory
5 Finding Your Way Around
BASIC
6 Getting at the Variables
7 FAST and SLOW Mode
8 Manipulating Memory Space
9 Aborting
10 Writing to the TV Screen
11 Communication and Passing
Parameters
12 Reading the Keyboard
13 Scanning BASIC
14 The Floating Point Calcu-
lator
15 The INs and OUTs of Tape
Read/Write
16 Programming and Debugging
Hints
Every chapter contains program listings that do real things–for example read a tape into a space above RAMTOP–that enable you to do something more with your machine. You don’t need a lot of knowledge to use these routines, but as you use them you’ll find other MC books making more sense. If you already know Z80 code, you’ll get the ROM environment and utilities straight.
One of the strongest features of this book is it’s accuracy. All routines were re-entered from the galley proofs to make sure they did not contain typos. The assembler listing came directly from Dave’s computer and 80-column printer. I found only line 6990 difficult to enter–use shift Q for the quotes enclosing the right parenthesis.
Privately, Dave told SYNTAX that most of the 8K ROM functions exist–using the same code–in the TS2068. Only the display and tape handling differ substantially. He figures about half the book applies to the 2068. By extension, a like fraction should apply to your ZX Spectrum or to the emulators.