## Table of Contents **Chapter 1 – Basic Programming Concepts .......... 5**\ Introduction ....................................... 5\ PRINT, LET, programs and line numbers ............. 5\ Variables and Arrays ............................... 6\ Assignments ........................................ 6\ Labels .............................................. 8\ Using LIST, RUN and cursors to edit and run programs 8\ REM, NEW, INPUT and GO TO .......................... 9\ Using STOP, BREAK and CONTINUE .................... 10\ Error trapping ..................................... 13\ **ERROR** *[n]* .......................................... 14 **Chapter 2 – Decisions ............................. 16**\ Making decisions ................................... 16\ Using IF to make decisions ......................... 16\ ELSE ............................................... 17\ Case selection with ON ............................. 19\ Decisions with the ? operator ...................... 19 **Chapter 3 – Looping ............................... 21**\ Using FOR, TO and NEXT ............................. 21\ **STEP** ............................................... 22\ EXIT ............................................... 23\ REPEAT...REPEAT UNTIL loops ........................ 24\ WHILE ............................................... 25\ Error trapping within REPEAT...REPEAT UNTIL loops .. 26 **Chapter 4 – Procedures and Subroutines ............ 27**\ Branching .......................................... 27\ GO SUB and RETURN .................................. 27\ LOCAL keyword ...................................... 28\ PRIVATE and PRIVATE CLEAR .......................... 29\ Procedures (DEFPROC / ENDPROC / PROC) .............. 29\ Passing parameters by reference with REF ........... 32\ Reading parameters with DATA and READ .............. 33\ Trapping errors locally ............................. 33 **Chapter 5 – READ, DATA, RESTORE ................... 35**\ READ, DATA and RESTORE ............................. 35\ **DATA (function) .................................... 36** **Chapter 6 – Expressions ........................... 37**\ Mathematical operations +, - , \* , /, MOD .......... 37\ Order of mathematical calculations ................. 37\ Bitwise, relational and logical operators .......... 37\ Unary/Bitwise NOT (!) .............................. 38\ Bitwise operators <<, >>, &, |, ↑, ↑| .............. 38\ Expressions ......................................... 39\ Variable names and limitations ..................... 39\ Scientific notation ................................. 40\ Decimal, Binary and Hexadecimal numbers ............ 41\ More about Integer Expressions and Variables ....... 41\ Signed vs Unsigned Integer Expressions ............. 45 **Chapter 7 – Strings ............................... 49**\ Introduction ........................................ 49\ String slicing, using TO ........................... 49\ String multiplication using the \* operator ......... 50\ Transforming a string with trailing modifers ....... 51\ Tokenisation of strings ............................. 51 **Chapter 8 – Functions ............................. 52**\ Order of calculations using functions .............. 52\ String functions .................................... 53\ LEN ................................................. 53\ STR$ ................................................ 53\ IN .................................................. 54\ VAL and VAL$ ........................................ 55\ Numeric functions ................................... 55\ SGN ................................................. 55\ ABS ................................................. 56\ **INT ................................................. 56**\ SQR ................................................. 56\ User defined functions using DEF and FN ............ 56\ NextBASIC functions within integer expressions ..... 58 **Chapter 9 – Mathematical Functions ................ 60**\ ↑ and EXP ........................................... 60\ LN .................................................. 61\ PI .................................................. 61\ Trigonometry with SIN, COS, TAN, ASN, ACS and ATN .. 62 **Chapter 10 – Random Numbers ....................... 64**\ RANDOMIZE, RND and % RND ........................... 64 **Chapter 11 – Arrays ................................ 67**\ DIM ................................................. 67\ DIM function ........................................ 70 **Chapter 12 – Conditions ............................ 71**\ AND, OR and NOT ..................................... 71 **Chapter 13 – The Character Set ..................... 74**\ CHR$ and CODE ....................................... 74\ The graphics symbols ................................ 74\ Tokens .............................................. 75\ BIN and USR ......................................... 75\ POKE and PEEK ....................................... 76\ Alternative Character Sets .......................... 79\ Character Graphics Mode ............................ 80 **Chapter 14 – More about PRINT and INPUT ........... 81**\ Coordinate Systems .................................. 81\ Screen Modes and Pixel Coordinates .................. 81\ Changing the size of characters ..................... 82\ Using AT to print to a certain location ............. 82\ Using POINT to print to a certain location .......... 85\ SCREEN$ ............................................. 88\ TAB ................................................. 88\ CLS ................................................. 89\ Scrolling ........................................... 89\ Expanding on INPUT .................................. 90\ LINE input .......................................... 91\ Using Expressions for INPUT ......................... 91\ Using control codes with PRINT ...................... 92\ INKEY$ .............................................. 93\ Using INPUT for game controllers .................... 93 **Chapter 15 – Colours ............................... 95**\ An introduction to colour on the ZX Spectrum Next ... 95\ Basics of computer colour ........................... 95\ Colour organisation and representation .............. 95\ Spatial vs Colour Resolution ........................ 95\ Colour attribute display ............................ 98\ Extended colour attribute display ................... 100\ Palette-based hybrid linear bitmapped colour display 101\ Layer 3 colour storage .............................. 102\ Layer 2 priority colours ............................ 102\ More on the LAYER command ........................... 103\ BORDER, PAPER, INK, BRIGHT and FLASH ................ 105\ BORDER .............................................. 107\ INVERSE and OVER .................................... 107\ Using colour control codes .......................... 107\ ATTR ................................................ 108\ PALETTE ............................................. 108 **Chapter 16 – Graphics .............................. 113**\ PLOT ................................................ 113\ DRAW and CIRCLE ..................................... 114\ POINT, POINT TO ..................................... 116\ Using OVER and INVERSE with graphics commands ...... 117\ Using stippling patterns to generate additional colours 118\ Quick erase and fill using LAYER ERASE .............. 118\ Clipping windows .................................... 118\ Tiling ............................................... 119\ Accessing non-supported graphics modes .............. 120 **Chapter 17 – Time and Motion ........................ 121**\ PAUSE ............................................... 121\ Using POKE and PEEK at the System Variables ......... 122\ TIME (command/function) ............................. 122\ Retrieving information from the RTC ................. 122\ TIME$ ............................................... 123\ INKEY$ .............................................. 125\ Animation: a quick primer ........................... 125\ Mass Storage Frame Playback ......................... 125\ Memory Based Frame Playback ......................... 127\ Animation with the Sprite System .................... 128\ Creating Sprites ..................................... 128\ Putting Sprites on Screen ............................ 130\ Animating Sprites .................................... 132\ Moving Sprites on Screen ............................. 134\ Relative sprites ..................................... 136 Composite vs Unified sprites ....................... 136\ Batching ............................................ 137\ Automatic sprite movement ........................... 137\ Sprite functions .................................... 139\ Scrolling ........................................... 140\ The Copper .......................................... 140 **Chapter 18 – Sound and Music ....................... 144**\ Basic sounds with the BEEP command .................. 144\ Enhanced Sound and Music with PLAY .................. 147\ Using the PLAY command .............................. 147\ Constructing strings ................................ 148\ PLAY command summary ................................ 148\ Setting the pitch ................................... 148\ Note duration ....................................... 149\ The N Command ....................................... 151\ Note volume ......................................... 151\ Volume effects ....................................... 151\ Tempo ............................................... 152\ Repeated phrases ..................................... 152\ The H command ....................................... 153\ Comments ............................................ 153\ Channel selection ................................... 153\ Stereo control ....................................... 153\ Digital Audio ....................................... 153\ WAV ................................................. 154\ MOD ................................................. 154\ PT3 ................................................. 154\ Using the Pi accelerator for audio ................... 154\ External Audio Output ................................ 155 **Chapter 19 – NextZXOS and alternatives ............. 157**\ Guide to NextZXOS ................................... 157\ NextZXOS main features .............................. 157\ Files, Drives, Partitions and Disks .................. 158\ Working with files .................................. 158\ Filenames ........................................... 159\ LOAD ................................................ 160\ SAVE ................................................ 164\ VERIFY .............................................. 168\ MERGE ............................................... 169\ Using NextZXOS ...................................... 170\ Wildcards ........................................... 170\ Filesystems ......................................... 171\ Partitions .......................................... 171\ Storage devices and disks ............................ 171\ Mounting ............................................ 172\ Drive cataloguing ................................... 173\ Drive, Folder and User Area navigation and management 177\ MKDIR ............................................... 178\ RMDIR ............................................... 178\ CD .................................................. 179\ PWD ................................................. 180\ Managing files and their attributes .................. 181\ COPY ................................................ 181\ ERASE ............................................... 182\ MOVE ................................................ 183\ File attributes ...................................... 184\ The RAMdisk ......................................... 186\ Drive and Partition Management ...................... 186\ CAT TAB and CAT ASN .................................. 186\ MOVE ... IN, MOVE ... OUT and REMOUNT ............... 187\ Virtual filesystem management – .mkdata and .mkswap .. 188\ Printing ............................................ 189\ The SPECTRUM command ................................ 189\ Speed Control ....................................... 191\ NextBASIC Editor and Program support commands ....... 192\ The Browser ......................................... 193\ The Browser Window .................................. 193\ Using the Browser ................................... 194\ Configuring the Browser .............................. 196\ The Command Line ..................................... 196\ ROM Cartridge Loaders ................................ 197\ 48K BASIC ........................................... 197\ 128K BASIC .......................................... 197\ ZX80 and ZX81 BASIC .................................. 197\ NMI Menu ............................................ 197\ The NextZXOS folder structure ........................ 199\ NextZXOS dot commands ................................ 199\ Modifying the startup – Autoexec.bas ................. 200\ CP/M ................................................ 201\ Preparing your ZX Spectrum Next for esxDOS ........... 204 **Chapter 20 – Channels, Streams,**\ Drivers and Windows ................................. 206\ Channels ............................................ 206\ Streams ............................................. 208\ Using Streams ....................................... 208\ Stream control commands .............................. 208\ The Variable and Memory Channels ..................... 211\ Installable device drivers and Driver Channels ....... 213\ Driver Channel support ............................... 213\ Windows ............................................. 214\ System Windows vs User Windows ....................... 214\ User character sets .................................. 216\ Window input ......................................... 217\ Window definitions ................................... 217 **Chapter 21 – Optional Features ...................... 220**\ Overview ............................................ 220\ Installation (for Issue 2 mainboards) ................ 220\ Raspberry Pi Zero installation on the Issue 4 mainboard 222\ Testing the add-ons' installation .................... 222\ A. Testing the memory ................................ 223\ Using the Real Time Clock hardware ................... 227\ Using the RTC together with the WiFi module .......... 228\ Using the rest of the add-ons ........................ 228 **Chapter 22 – IN, OUT and the**\ Next Registers ...................................... 229\ IN and OUT .......................................... 229\ Hardware address decoding ............................ 229\ Accessing the ZX Spectrum Next features with NextREG . 232\ The Next Registers .................................. 234\ The Expansion Bus ................................... 246 **Chapter 23 – The Memory ............................ 247**\ Overview ............................................ 247\ ROM and RAM ......................................... 247\ The Memory Map ...................................... 247\ Memory Management ................................... 248\ Reading and Writing to Memory ........................ 249\ NextZXOS and NextBASIC memory allocation ............. 251\ Memory Areas and their use ........................... 252\ NextBASIC Data Structures ............................ 253\ PEEK, POKE and their variants ........................ 256\ CLEAR ............................................... 259\ Memory Bank management with BANK .................... 259\ Using BANK with graphics ............................. 262\ Using BANK with files ................................ 264\ Extending NextBASIC Programs with BANK ............... 265\ NextZXOS Paging Mechanism Overview ................... 265\ MMU-Based Memory Management .......................... 269\ Layer 2 Bank Switching ............................... 269\ Paging method interactions ........................... 269\ Paging out the ROM ................................... 269 **Chapter 24 – The System Variables ................... 271**\ Overview ............................................ 271\ System Variables ..................................... 271 **Chapter 25 – Using Machine Code ..................... 275**\ Using Machine Code ................................... 275\ Using CLEAR to Make Space ............................ 275\ Using USR to run machine code ........................ 276\ Calling NextZXOS from NextBASIC ...................... 278\ Opcodes Prefixes ..................................... 281 **Appendix A – Character Set, Z80N**\ Mnemonics and Control Codes ......................... 282 **Appendix B – Reference .............................. 288**\ Reports and Error Codes .............................. 288\ General Errors ....................................... 288\ Storage Device Related Errors ........................ 290\ NextBASIC Keywords and Functions ..................... 291\ The Decimal System ................................... 295\ The Binary System .................................... 295\ The Hexadecimal System ............................... 295\ Bits, Bytes and Words ................................ 296\ Using Binary and Hex in NextBASIC .................... 296 **Appendix C – Machine Personalities .................. 297**\ Overview ............................................ 297\ The Cores and their update procedures ................ 297\ Regular Core update .................................. 298\ AB Core update ....................................... 298\ Multicore (Extra Cores) update ........................ 299 Updating the firmware ................................ 299\ Updating the System/Next™ distribution ............... 300\ Selecting and configuring a personality .............. 300\ Troubleshooting ....................................... 302\ Other things to look for .............................. 302 **Appendix D– The Calculator ........................... 303**\ Selecting the calculator .............................. 303\ Entering numbers ...................................... 303\ Running total .......................................... 303\ Using built-in mathematical functions ................. 304\ Editing the screen ..................................... 304\ Assigning variables .................................... 304\ User defined functions ................................. 304\ Exiting from the calculator ............................ 305 **Acknowledgements ...................................... 307** **Table Of Contents ..................................... 309** **Index ................................................. 312** **Technical Specifications .............................. 317**\ Issue 2 ............................................... 317\ Issue 4 ............................................... 318