The Sinclair ZX Spectrum Next


Back in early 2017, a new Kickstarter campaign was initiated by Enrique Olifiers to build what would be the successor to the Sinclair ZX Spectrum line of computers. His vision was to build something that would have been the next generation of Speccy - the '+4' if you like - a fully realised and fully compatible ZX Spectrum computer which could also create its own identity through its expanded capabilities. The objective then was to deliver a computer which could run up to twice as fast as the original Spectrum models, to increase its memory to a lofty 512KB RAM, and to introduce new video modes which would give the ZX Spectrum Next a palette and graphics capabilities worthy of its ambition and push into the future of the platform.

The Kickstarter was a resounding success, achieving over £720,000 backed by 3,113 individuals.

Designed by famed Sinclair Industrial Designer, Rick Dickinson and his business partner Phil Candy, it is very apparent where this new machine has its roots. From the black finish and oval keys to the modern equivalent of the rainbow stripe on the right hand side, this is 100% Sinclair.

From the Kickstarter campaign page:

"The ZX Spectrum was a revolution in personal computing whose impact is still felt to this very day, 38 years after its original launch by Sinclair. A generation of developers, artists and designers took their first steps into the art of software development using a Spectrum, a machine that broke out of a computing niche to touch the hearts of millions of people around the world.

Few memories are as powerful as finding a Spectrum under your Christmas tree or as a birthday gift, unboxing it to unveil an icon of design whose ease of use got people from all walks of life into programming and gaming. So powerful was the impact of the Spectrum that new games and apps are still produced for it to this very day, making it one of the most enduring machines of all time.".

With new video modes, co-processors, more colours, sound channels, faster speeds, large storage and networking capabilities, the Spectrum Next leads the way for a generation of new games and apps created with the same philosophy that made the ZX Spectrum an icon, and the most successful home computer in British history.

Since the original Kickstarter back in 2017, the team have refined the ZX Spectrum Next into what it is today - vastly expanded with many features not though of when their journey began.

The ZX Spectrum Next is fully compatible with the original Spectrum 48, 128, +2, +3 and even some clones such as the Russian Pentagon, allowing it to run virtually every piece of software available. Its hardware is implemented in FPGA technology, with no emulation in sight. It’s capable of running the original games with enhanced capabilities, such as faster processing speed boosting 3D titles, or even loading them from tape if you want the original feeling. It supports most expansion boards made for the original ZX Spectrum via its Expansion Port, and connects to several different types of monitors, including RGB (Scart), VGA and HDMI.

Its Origins

The ZX Spectrum Next was born out of the brains of Victor Trucco and Fabio Belavenuto, retro hardware developers who created the TBBlue bitstream upon which the Next is based (‘T’ from Trucco, ‘B’ from Belavenuto, and Blue because… well, because the board is blue!) Early ideas came about in late 2015 to create a spiritual successor to the ZX Spectrum - one that would have Sinclair's approval. In December Olifiers approached Rick Dickinson, the designer of the original ZX Spectrum, to see if he would be interested in taking on the role of Industrial Designer for the project, which he enthusiastically accepted. Work got under way and the team expanded to include firmware authors and more. The team had very little overall experience manufacturing a physical computer, but after almost 3 years their hard work paid off. On 6th February 2020 the first ZX Spectrum Next was delivered to the first backer. The next 3,000 followed, and once in the hands of reviewers and public it was met with great feedback and applause.

From left to right: Rick Dickinson, Victor Trucco, Fabio Belavenuto, Jim Bagley, and Henrique Olifiers

The ZX Spectrum Next is fueled by its community, and there are dozens of collaborators who daily improve what it’s capable of.


Kickstarter #1 Pledges

During the first Kickstarter campaign which was launched on 23rd April 2017 and ran to 23rd May 2017. The options to pledge were as follows:

Pledge Amount Description
£99 Just the Board - no case, no accessories
£165 ZX Spectrum Next Early Bird - The ZX Spectrum Next computer, at a special price for those lightning-fast at getting one!
£175 ZX Spectrum Next - 512KB RAM, HDMI out, 7 MHz, Accelerator port, SD card
£215 ZX Spectrum Next Plus - All the features of the normal version, plus Real Time Clock and Wi-Fi module added
£230 ZX Next Accelerated - All the features of the Plus version, plus the Raspberry Pi Zero accelerator plugged into the accelerator port
£250 ZX Next Yours Truly - Receive a ZX Spectrum Next Plus (RTC, Wi-Fi) computer with your name laser-etched onto it, making it a one of a kind machine.
£275 ZX Next Joystick Game Pack - ZX Spectrum Next computer + boxed Kempston Joystick signed by Jim Bagley.
£340 Next Bundle x2 - Two Spectrum Next, both with 512MB RAM, HDMI out, 7 MHz, Accelerator port, SD card
£375 ZX Next Jim Bagley Games - Signed ZX Spectrum games package by Jim Bagley + ZX Spectrum Next. Games are: Cabal, Midnight Resistance and Throne of Fire.
£1,000 Ultimate ZX Spectrum Next - The first 5 machines to roll out of the production line (pimped out with the Plus specs and the accelerator), internally signed by all members of the team, and an authenticity certificate. Your name will be featured on the BIOS of the Next, credited as a part of the effort, shown in the settings screen of the machine. Legendary! A framed, high-quality and signed blueprint of the ZX Spectrum Next to hang on the wall. You also get to meet Henrique Olifiers and Jim Bagley over dinner in London with the option of getting the machine hand-delivered at the occasion (photos galore!)
£5,000 There Can Be Only One - A ZX Spectrum Next numbered #0, fully expanded with all the optionals, internally signed by the entire team, with an authenticity certificate. Two historic collectible prototype boards Issue 0 and Issue 1 (only 10 of each were ever made) framed over a high-quality blueprint of the computer, all signed. Your name in the settings screen of the ZX Next as a member of the team who backed the project and helped make it happen. Join us for dinner with the backers of the 'Ultimate' tier. Feature on the tech demo of the Next included with every machine, showing its capabilities -- you get to brainstorm the demo with the team and chose how and where you're featured.

There was overwhelming demand for the 'Accelerated' version.

Kickstarter #1 Stretch Goals

The first stretch goal during the first Kickstarter campaign was £400,000. If this was to be met, all Nexts would be graced with an SLX16 FPGA chip instead of an SLX9. This, according to the official site meant "over 5,000 more logic elements for graphic goodness!". With 21 days to go, this was hit by a total of 1,743 backers.
Stretch goal #2 was £450,000. If this was met, RAM and Wi-Fi sockets would be added. This too, was met with the number of backers now at 2,000.
Stretch goal #3 was added on 12th May 2017, which would be Rex Next = a classic game remastered for the Next.
The fourth stretch goal was set at £500,000 which doubled the memory from 512KB to 1MB in each Next sold.
The fifth stretch goal was £550,000, which would mean everyone would get a printed manual.
At six, £590,000, and two games are unlocked: Dreamworld Pogie and No Fate!
When the funding reached £600,000 another stretch goal was realised. The Internet Toolbox which will provide the mechanism and a suite of programs for connecting the ZX Spectrum Next to internet services.
On 21st May 2017, the Kickstarter reached £625,000 and this unlocked another much wanted tier, the "Box of Memories". Now there would be a box you can be proud of!
On 22nd May 2017 moved it into the last 24 hours of the Kickstarter and what a ride it had been. Not only did the funding hit the £650,000 mark but it also unlocked yet another stretch goal. Twin joystick ports!  This would prove to be a difficult thing to deliver, as the original board design had a single port to the left-hand side. One idea was to have one of the ports on the left side of the unit, and the second on the left front of the unit. Provision was eventually made and it was determined the two ports were shifted along to the right, both on the front.


Kickstarter #2 Pledges

For the second Kickstarter campaign (called "ZX Spectrum Next Issue 2") which was started at 9pm BST on 11th August 2020, the goal remained the same as the first: £250,000. Within 10 minutes of the campaign starting, pledges were at £345,000 by 1,000 backers.
Retro Isle was backer #150 (we sadly missed out on the first campaign). Expected delivery is Aug 2021.
After 20 minutes pledges had reached £428K from 1,230 backers. At that time, 100 backers got the Early Bird one, 216 backers did the same as us with the Plus, 787 chose the Accelerated one, 10 chose the Plus x2 deal, and 54 chose the Accelerated x2 deal. It doubled its goal, reaching £500K and 1438 backers after 40 minutes.
At 8am the following morning, it was up to £683,756 with 1,950 backers.The options to pledge were as follows:

Pledge Amount Description
£280 ZX Spectrum Next Plus Early Bird (first 100 backers) - 1MB RAM, RGB/VGA/HDMI out, 7/14/28 MHz Turbo modes, accelerator port, SD card, PSU, Printed manual, Wi-Fi module and Real Time Clock
£300 ZX Spectrum Next Plus - as above
£325 ZX Spectrum Next Accelerated - Same as Plus but with Accelerator board installed
£590 ZX Spectrum Next Plus x2 - 2x ZX Spectrum Next computers. No accelerator board
£640 ZX Spectrum Next Accelerated x2 - 2x ZX Spectrum Next computers with accelerator boards

Kickstarter #2 Stretch Goals

As is normal for Kickstarter campaigns, there were some stretch goals added after the initial funding goal was reached. The one on the left was the initial set, and on the right is the one published on 14th August 2020, the day funding went over £1M.


The prices for Issue 2 are higher. According to the Kickstarter campaign, the reasons for this were:

1) Taxes. "While we didn’t charge taxes on the first campaign following advice that crowdfunding was exempt, the taxman said we owed them. The team footed the bill themselves at huge personal cost. This time around we’ve added tax to the price, which is the lion’s share of the price difference."

2) Components. "Some of the parts employed on the Next have gone up in price in the past three years, in particular the FPGA and the RAM chips. This is the second factor composing the price."

3) Assembly and Test. "Less than 0.3% of the Nexts from the first campaign had to resort to warranty or repairs of some kind, an industry-beating quality standard. This high watermark was achieved due to the Next being built and tested in the United Kingdom at cutting-edge facilities. The testing procedures we deployed were more thorough than originally planned, and their costs are now reflected."

Issue 2 machines would be built using the same build and test facilities as Issue 1 machines, to minimise risk to quality and delivery.


Board Revisions

The Spectrum Next board has gone through a number of revisions over its lifetime:

Issue 2 - Board design was completed on 28th June 2017. This allowed for a 'snap-off' daughterboard, depending on whether you bought the 'board only' version for installation into an original Spectrum 16K/48K case, or the cased version. With the cased version being wider than the original Spectrum case, this snap-off daughterboard was in place to the left side, extending the SD card slot and three buttons outwards. This daughterboard design meant a single mainboard could be manufactured that would work with both board-only and cased versions. Also in the Issue 2 board design, the Raspberry Pi Zero was relocated to the back of the machine. This aligned the ports front and rear, but did give rise to the eventual necessary case bulge at the rear.
Issue 2A - An evolution of the Issue 2 board, and the first public version, different mainly because it has the daughterboard section seperated onto its own PCB. The main problem with the Issue 2A board was the inclusion of RAM sockets - one of the many stretch goals that the project reached during its Kickstarter. The 36-pin original RAM sockets had long since stopped being manufactured, but a 40-pin variant was eventually sourced and used. This is the board revision most KS#1 backers have. One problem identified with this revision is noise/video interference caused by the PSU noise filtering through into the board's components. This interference may vary from no side effect at all (most users) to video noise to HDMI incompatibilities. In order to fix the problem, a capacitor must be soldered to the 2A board voltage input, thus eliminating interferences.
Issue 2B - Manufacturing of issue 2B boards began on 16th August 2018. This version added minor improvements such as the PSU capacitor, joystick port headers were added to the left side (for Next cased boards) in addition to keeping the ones on the right (for original 48K case fitment).
Issue 2C - The first boards designed for Kickstarter #2. At the time of writing this, KS2 is only 1 day in, so it's early days. Planned features are expansion port protection, repositioning of the Wi-Fi module for less interference and boosted signal, and digital port power feedback mitigation.



The Spectrum Next's base spec sheet certainly demonstrates a leap over the original, bringing it up to modern technological compatibility, and with future expansion in mind:

  Kickstarer Issue 1 Machines Kickstarer Issue 2 Machines
Processor Z80 3.5Mhz and 7Mhz modes* Z80 3.5MHz, 7MHz, 14MHz and 28MHz turbo modes
Memory 512Kb RAM (expandable to 1.5Mb internally and 2.5Mb externally) 1Mb RAM (expandable to 2Mb internally)**
Video Hardware sprites, 256 colours mode, Timex 8x1 mode etc. 256 & 512 colour modes, 256x192 & 640x256 high resolution mode
Video Output RGB, VGA, HDMI RGB, VGA, HDMI, 50Hz and 60Hz modes
Extra Hardware   Hardware sprites, DMA, Copper, Enhanced ULA, Tilemap, Layer2
Storage SD Card slot, with DivMMC-compatible protocol
Audio 9 channels via 3x AY-3-8912 chips with stereo, plus 2x 8bit DACs output
Joystick 2 ports compatible with Cursor, Kempston and Interface 2
PS/2 port Mouse with Kempston mode emulation and/or external keyboard
Special Multiface functionality for memory access, savegames, cheats etc.
Tape support Mic and Ear ports for tape loading and saving Combined Mic and Ear port for tape loading and saving
Expansion Original external bus expansion port and accelerator expansion port
Accelerator board (optional) GPU / 1GHz CPU / 512Mb RAM
Network Wi Fi module
Extras Real Time Clock
OS NextZXOS and NextBasic featuring expanded commands set

* 14 and 28 MHz modes were added to the firmware in June 2017 after further testing to ensure the hardware could cope.
** Standard memory was increased to 2MB due to $600K stretch goal being reached.

Plus vs Accelerated

The only difference between a Plus model and an Accelerated model is the inclusion of a Raspberry Pi Zero W installed into the 'accelerator' port and a 'NextPi' SD card. What does this add, you might be asking...
The Pi Zero acts as a co-processor to assist the Next's main processor, enabling it to utilise a 3D GPU (graphics processing unit), an additional 512 MB of RAM, and a powerful ARM processor.

The Spectrum Next Accelerated version has a Raspberry Pi Zero installed on its plastic standoffs at the rear of the computer


Currently the Raspberry Pi can be used to load digital .TZX files as analogue cassette tape (the Plus model only supports the loading of .TAP images), as well as SID emulation for playback of .SID files and hopefully in the future be used to provide better game audio, and other music format playback. There is also talk of USB joystick support being added through the Raspberry Pi Zero's micro USB port to the Next. Another possibility for the future is to use the Pi Zero's mini HDMI output to drive a second display. Other new features may come in the future through software updates and Next software making use of the Pi.

A Spectrum Next Plus can be upgraded to an Accelerated by adding your own Pi Zero with the correct header to the accelerator port.


Firmware and Cores

At its heart, the Next has an FPGA - a Field-Programmable Gate Array - instead of a CPU. This essentially allows you to install a 'core' which mimics certain hardware - the standard Next core mimics the original circuitry of the Sinclair ZX Spectrum: a Zilog Z80 CPU, ULA, Sinclair BASIC ROM, etc. You can store multiple cores in the Next's flash memory, and the Next's firmware, called TBBlue, can then run any of these cores. For example, you can put a BBC Model B core into the Next's flash memory and after a hard reset of the computer (or by running the .CORE command from NextBASIC) that core can be run instead of the standard Spectrum Next core. At the time of writing this article, a number of unofficial cores have already been developed and released, including:

  • Atari 2600
  • Arcade
  • Acorn Atom
  • Acorn BBC Model B and Master
  • Amstrad CPC6128
  • Colecovision
  • Intellivision
  • Magnavox Odyssey 2
  • MSX 1
  • Nintendo Entertainment System (NES)

The Spectrum Next comes with an 'anti brick' system that allows recovery of a machine in case of an unsuccessful firmware update.

New Video Modes and Hardware Sprites

Something the original line of ZX Spectrums never got was an upgrade to its graphics capabilities. The maximum screen resolution was 256x192 pixels [not including the border] from the earliest 16K rubber-keyed Speccy up to the final +2B and +3B systems from Amstrad. The screen is further divided into 8x8 "attribute cells", each of which is 32x24 pixels and can support only 2 colours within an attribute cell. The Speccy also retained a palette of 15 colours (8 colours + 7 of the same in 'bright') throughout its lifetime.

With the design of the Spectrum Next, this was an obvious area to bring it to the next level. The Spectrum Next has what they call an Enhanced ULA, replacing the original ULA which is responsible for [among many other things] video output. Whilst retaining the original 256x192 resolution, the Next can display 256 colours on-screen at once. It also supports other screen resolutions:

  • LoRes Layer mode: Reduced resolution traded off for more colours. Allows any of the 256 colours anywhere on screen, but reduces resolution to 128x96.
  • Timex Sinclair Hi-Color mode: Keeps the 256x192 resolution, but disables the standard attribute area such that each attribute byte is now applied to only one line of each cell. Reduces colour clash to areas of 8x1 blocks instead of 8x8 blocks.
  • Timex Sinclair Hi-Res mode: Horizontal screen resolution is doubled, resulting in 512x192. Attributes are disabled, though this means only 2 colours are supported.

In addition to the Enhanced ULA, Spectrum Next also adds 128 hardware sprites, Layer 2 and a Tilemap, all of which are not ULA-controlled. Sprites are 16x16 pixels and can be mirrored, rotated, and scaled 2x, 4x or 8x. Layer 2 provides a second 256-colour screen up to 640x256 resolution, in which every pixel can be individually coloured. This graphics layer can be behind, in front of, or above the ULA screen. Tilemap is a screen mode similar to hardware text modes, able to display 40x32 or 80x32 16-colour 8x8 tiles.

Better Audio

The Spectrum 128 and beyond enhanced the original Speccy's audio from a simple beeper to 3-channel monoaural sound via the Yamaha AY-3-8912 chip. This was a huge leap at the time, bringing the Spectrum closer to its 8-bit rivals for sound output.

With the Spectrum Next things are much enhanced again. In what is dubbed Turbo Sound Next, the Next's audio system has no less than three Yamaha AY-3-8910 chips, able to output 9-channel stereo sound to either HDMI, 3.5mm audio jack or an optional internal speaker. Coupled with this are four 8-bit DACs (digital-to-analog converter) - two for the left channel and two for the right channel. Furthermore, with the optional Raspberry Pi Zero W accelerator, audio generated by the Pi can be mixed in with the internal next audio stream, or can be mapped to EAR for tape loading.