The Sinclair ZX Spectrum +3 manual is copyright Amstrad Plc., Amstrad has kindly given it's permission for the reproduction of this text.
Acknowledgements:
Cliff Lawson and Amstrad for allowing the reproduction of this text.
The text was taken from a transcription of the ZX Spectrum +3 manual by Russell Marks, with the help of
Thomas Ahn Kjaer and Ian Coates, he produced a text version of the manual. I've taken this text and produced this
HTML version. Here's the original readme that was distributed with Russell's version.
Unfortunately, Russell's e-mail address no longer works so I have been unable to notify him of this version
Still to do...
most of the chapters consist simply of the original text contained in <PRE> tags. These will be updated. Also graphics, diagrams etc.
| Introduction | Software compatibility, The BASIC, How to read this book, Precautions. | 
| Chapter 1: Open the box | Unpacking, Fitting a mains plug, Setting up. | 
| Chapter 2: Operating your +3 | Switching on, Tuning-in your TV, Using the +3, The opening menu. | 
| Chapter 3: How to load disk software | Disks for the +3, Loading disk software, Abandoning loading. | 
| Chapter 4: How to load tape software | Using tape instead of disk, Loading Spectrum +3, Spectrum +2 and Spectrum 128 software, Loading Spectrum 48 software, Abandoning loading. | 
| Chapter 5: The +3 disk drive | Disks and drives, Insertion, Write protection, Read/write indicator lamp, Eject button. | 
| Chapter 6: Introducing +3 BASIC | The editor, The edit menu, Renumbering a BASIC program, Swapping screens, Listing to the printer, Typing in a program, Moving the cursor, Running a program, Commands and instructions, Simple disk operations, Formatting a disk, Saving a program, Filenames, Disk catalog, Loading a program, Error reports. | 
| Chapter 7: Using 48 BASIC | Using the +3 as a 48K Spectrum Entering 48 BASIC mode The keyboard under 48 BASIC Program entry Editing the current line | 
| Chapter 8: The +3 BASIC programmer's guide | |
| Part 1: Introduction | General intro to program entry in +3, BASIC, how the keyboard functions, program entry. | 
| Part 2: Simple programming concepts | Programs, Line numbers, Editing programs using the cursor keys, RUN, LIST, GO TO, CONTINUE, INPUT, NEW, REM, PRINT, Stopping a program. | 
| Part 3: Decisions | CLS, IF, STOP, =, <, >, <=, >=, <> | 
| Part 4: Looping | FOR, NEXT, TO, STEP | 
| Part 5: Subroutines | GO SUB, RETURN | 
| Part 6: Data in programs | READ, DATA, RESTORE | 
| Part 7: Expressions | Operations: +, -, *, /, Expressions, scientific notation, variable names | 
| Part 8: Strings | Slicing, using TO | 
| Part 9: Functions | LEN, STR$, VAL, SGN, ABS, INT, SQR, DEF FN | 
| Part 10: Mathematical functions | ^, PI, EXP, LN, SIN, COS, TAN, ASN, ACS, ATN | 
| Part 11: Random Numbers | RANDOMIZE, RND | 
| Part 12: Arrays | Arrays, DIM | 
| Part 13: Conditions | AND, OR, NOT | 
| Part 14: The Character Set | CODE, CHR$, POKE, PEEK, USR, BIN | 
| Part 15: More about PRINT and INPUT | CLS, PRINT items, Expressions (numeric or string type), TAB numeric expression, AT numeric expression, PRINT separators (, ; '), INPUT items, Variables (numeric or string type), LINE string variable, Scrolling, SCREEN$ | 
| Part 16: Colours | INK, PAPER, FLASH, BRIGHT, INVERSE, OVER, BORDER | 
| Part 17: Graphics | PLOT, DRAW, CIRCLE, Pixels | 
| Part 18: Timing | PAUSE, PEEK, INKEY$ | 
| Part 19: Sound | BEEP, PLAY | 
| Part 20: File operations | Drives, FORMAT, Filenames, SAVE, LOAD, Disk catalog: CAT, Wildcards, MERGE, Deleting and renaming files, File attributes, ERASE, MOVE, COPY, The RAMdisk, Tape operations, VERIFY, Tape catalog: CAT | 
| Part 21: Printer operations | Parallel printers, Serial printers, LPRINT, LLIST, FORMAT, COPY | 
| Part 22: Streams | Streams, hannels, FORMAT, OPEN, CLOSE | 
| Part 23: IN and OUT | IN, OUT | 
| Part 24: The memory | PEEK, POKE, CLEAR, Memory management | 
| Part 25: The system variables | POKE, PEEK | 
| Part 26: Using machine code | USR with numeric argument | 
| Part 27: Guide to +3DOS | ROMs, +3DOS interface, File attributes and headers, Disk format and specification, Tracks and sectors, Disk parameter blocks, CP/M file compatibility, Changing disks, Logical to physical drive mapping, +3DOS messages and requirements, +3DOS routines | 
| Part 28: Spectrum character set | Control codes, Characters, Z80 assembler mnemonics | 
| Part 29: Reports | Reports and messages, CONTINUE | 
| Part 30: Reference section | Hardware | 
| Part 31: The BASIC | Number handling, Variables, Strings, Functions, Brief summary of keywords, Mathematical operations | 
| Part 32: Binary and hexadecimal | Number systems, Bits and bytes | 
| Part 33: Example programs | Renumber, Clock, Bustout, Telly tennis | 
| Chapter 9: Using the calculator | Selecting the calculator, Entering numbers, Running total, Using built-in mathematical functions, Editing the screen, Assigning variables, User defined functions, Exiting from the calculator | 
| Chapter 10: Peripherals for your +3 | Cassette unit, Printer, Additional disk drive, Joystick(s), VDU Monitor, Amplifier, Serial devices, MIDI device, Auxiliary interface, Expansion devices |