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