LATEST UPDATE 18th December - Chapter 10 to 12 downloads added.
NEXT TECH is a book for readers who treasure the creative aspects of the pre-PC home micro scene of the late 1970s and early 80s. It helps Spectrum Next owners to progress beyond the manual that came with their computer, providing them with inspiration, expert guidance and enthusiasm spread over 500 pages. It's written for the people for whom Sir Clive Sinclair created his computers in the first place.
The Sinclair ZX Spectrum Next packs 45 years of British home computing into a nifty designer case. It combines brilliant ideas from Sinclair, Amstrad, Acorn and the Amiga in a modern system made by industry professionals who never forgot the thrills of the early micros, and who had the vision and community spirit to develop that technology further for the 21st century. It's a lot to get your head around. So Simon N Goodwin, creator of Crash magazine's Tech Tips column, has written a specialist book to help you make the most of this amazing machine.
This is what Phoebus Dokos, author of the official manual included with every ZX Spectrum Next, says about Next Tech: If you've read the Spectrum Next manual and want more, this is it! Simon has been my Sinclair reference expert for more than thirty years - now he can be yours, too.
NEXT TECH is a celebration and source of inspiration expertly researched and written over six years. From simple hardware hacks to intricate, carefully explained software components - from BASIC commands through a structured cascade of POKEs, USR calls, custom chip registers, VHDL, pointer control, sprites, graphics and sound layers, coprocessors, DMA and Z80n machine code - NEXT TECH guides the reader down a fascinating trail from 1970s DIY culture and historical accidents to the FPGA silicon that powers the Next's cores and personalities.
NEXT TECH explores the creation stories, inner logic and endless potential of classic computers that do just what you ask of them... flexible, interactive, accessible micros designed for quick learners and creative minds, now enhanced with speed, memory and storage options unimaginable in the 1980s, not forgetting modern WiFi and HDMI.
Simon N Goodwin wrote and published hundreds of clear, informative articles about the heyday of home micro-computing as Technical Editor of Crash magazine, a frequent contributor to Your Spectrum, a writer for most other UK Sinclair magazines, Personal Computer World, Computer Shopper, Amiga Format and Wireframe columnist. Simon's programs have been marketed by Atari, ATD, Codemasters, Digital Precision, Dk'tronics, EA, Quicksilva, Sega and Zynga. Simon has contributed to the system software and design of Sinclair-based micros like MGT's SAM Coupé, CST's Thor and ZX Spectrum Next.
* Includes N-GO, Xberry Pi, a bit of ARM, lots of Zilog, and (almost) no Microsoft!
Next Tech is a 500-page book printed in clear, 11-point type with over a hundred illustrations, a comprehensive table of contents, and an eleven-page index at the back. The first chapter is an introduction and overview. Here's a rather condensed summary of the contents of the other chapters.
Chapter 2 delves into the details of Spectrum versions and compatibility, Next personalities, Configuration menus, Kickstarter 1 and 2 hardware differences, mouse and track-ball input options. It's mostly about hardware.
Chapter 3 explains why your modern monitor or telly might not entirely be an improvement on the one you shared in 1982, and what do about it. It discusses the pros and cons of SCART, VGA and HDMI displays, analogue screen testing, Screen capture, Composite video converter devices, and graphics configuration commands.
Chapter 4 covers hardware connections: recognising and making compatible tape leads, power supply issues, joystick choices and set-up, DIY optical input and output via the controller ports, adding a second SD slot, printing, configuring floppy discs and other plug-in interfaces. It's a chapter for hardware tinkerers, but you don't need to be able to solder to benefit from reading it, or to follow up on some of the hardware projects.
Chapter 5 turns towards software, and NextBASIC in particular. It explores BASIC benchmark speed-ups and remaining bottlenecks, program source tokenisation, variable-name look-ups, memory leaks, stream and esxDOS file operations, backups and file comparisons. It also discusses programming the Copper co-processor from BASIC for sound and graphical effects.
Chapters 6, 7 and 8 demonstrate recently-added features of NextBASIC. They present a carefully-designed text editor, while exploring the history of BASIC programming from Dartmouth College to NextBASIC 2.09, by example. The editor demonstrates how to program mouse selection and menus, keyboard polling, character sizes, integer optimisations - and the practicalities of splitting large programs and data into banks. In its own right, the text editor is a handy utility for configuration files and short texts, ripe for further customisation.
Chapter 9 details the history and development of Next systems, including ways to identify particular hardware and software versions and detect the availability of the Z80n processor. This will help you decide whether or not to upgrade your Spectrum Next and which older versions you might want to keep on spare SDs for backward-compatibility testing.
Chapter 10 dives into Z80n machine code with the first of two open-source drivers, capable of regularly running up to 64 'slot' routines in parallel with NextBASIC. This driver is written on Next with the Odin assembler. Chapter 11 demonstrates some driver 'slot routines' in action. The Z80n programs vary in length from three to almost 200 instructions. All are explained, step by step, without presuming machine-code expertise.
Chapter 12 builds substantially on the 'slot' driver and automatic sprite update system introduced in NextBASIC 2.06, with support for smoother movement and more complicated paths, including fast fixed-point arithmetic routines which take advantage of Z80n processor extensions.
Chapter 13 is all about Next's memory, explaining the difference between BASIC Banks and MMU Pages, with programs to read any RAM page and replace system fonts. After that it shows by example how to augment the Z80n by using the DMA co-processor for animation and audio streaming.
Chapter 14 tunes into Next's three built-in AY-3-8912 programmable sound generators, providing procedures to emulate BEEP better and play multi-channel audio without stopping the main NextBASIC program. It explains subtleties of program timing, and how to compensate for them in advance or on-the-fly.
Chapters 15 and 16 introduce a second driver, this time written to demonstrate the NextBASIC inline assembler. The TileDriver extends NextZXOS to allow BASIC programs to set up and PRINT Layer 3 hardware TileMap graphics, for larger (320 or 640x256 pixel), faster (0.5 or 1ms CLS) displays and animated fonts, plus sprite-like tile rotation and mirroring in hardware. all from NextBASIC and accessible to existing programs as well as new ones.
Next's FPGA is reprogrammable in hardware as well as software. Chapter 17 introduces Virtual Hardware Design and VHDL, contrasting synthesising an FPGA core with conventional programming, using examples from Next's own circuits and logic design. It shows programmers and old-school electronics hackers the principles of FPGA design, by comparison with familiar hardware and software, including contributions by SpecNext core maintainer and VHDL expert Allen Albright.
Chapter 18 demonstrates how much Next still has to offer beyond SpecNext's default configuration. It shows ways to run BBC BASIC inside NextZXOS, giving a massive increase in floating-point performance, comparing Sinclair and Acorn languages and operating systems.
NextZXOS can be temporarily replaced with alternative cores that implement Acorn computer hardware, including very capable audio and graphics add-ons, and the 'tube' co-processor interface which runs extremely fast and capacious programs on the Pi0 in parallel with Next's FPGA, with hardware display acceleration in megapixel 24-bit colour via the second HDMI port, controlled from Next through BASIC or other languages. Delivering on the 'accelerator' concept, the PiTubeDirect option brings decades of Acorn and Archimedes goodies to Next, RUNning unmodified BASIC programs thousands of times faster than an original BBC Micro, hundreds of times faster than any native Next BASIC. Programs to explore disc images and convert source between Sinclair, Acorn and Z80 BBC BASICs are included and explained in the book.
And of course there's a substantial index, right at the end. And as we find typos, we'll list any significant ones that affect the meaning here, and update the programs on the links below. Otherwise the book would never have got 'finished' ;-)
The text of Next Tech is not downloadable or currently available as an e-book, though parts can soon be previewed on the Amazon website, but it is planned as a series. Volume 1 will be made available digitally when the planned Volume 2 is printed, but not before 2026.
Page 23: fast RAM should read fast ROM (later, -> stands for 'should read')
Page 54: other lead is the anode -> other lead is the cathode. I got anode and cathode swapped over in the first proof, then 'corrected' it to refer to the anode twice, whoops. The bottom plate is the cathode.
Page 60: bug plug -> big plug
Page 72: the heading BM7 appears twice; the first should be BM6
Page 78: for Next board read KS1 or N-Go board
Page 97: one addition and -> two additions and one
Page 228: Just 93 should be just 83
Page 261: radius between 35 and 50
Page 328: StreamModule2 has a different base address and has been added to the downloads
Page 379: updates and updates -> output and updates
Page 382: EDIT -> TAB
Page 384: ESC -> ESC, CHR$
Page 397: TimeMap -> TileMap
Page 457: This program is for BBC BASIC V; the binary download has been adapted to suit BBC BASIC 2 (slowly)
Page 459: SID chip -> SID imitation
Page 461: The word Pixels is missing from the end of the INK line in Table 11
Page 5 (index) and
Page 68 - for uttons, read Buttons (thanks TJ)