ZX Spectrum Next

Sinclair ZX Spectrum Next is a modern 8-bit home computer, backwards compatible with the ZX Spectrum both in software and hardware, but also featuring enhanced capabilities.[2][3]. It is intended to appeal to retro-computing enthusiasts and also to "encourage a new generation of bedroom coders", according to project member Jim Bagley.[4]

Sinclair ZX Spectrum Next
DeveloperSpecNext Ltd.
ManufacturerSMS Electronics
TypeHome computer
Release dateDecember 2017 (Issue 1 development board), February 2020 (Issue 1 cased), August 2021 (Issue 2, estimated)
Units sold3010+ (3010 Issue 1 cased[1])
CPUZilog Z80 implemented in FPGA
Memory1 MiB (Issue 1, upgradeable to 2 MiB), 2 MiB (Issue 2)
PredecessorZX Spectrum 128

Despite the name, the machine is not directly affiliated with Sinclair Research Ltd., Sir Clive Sinclair or the current owner of the trademarks Sky Group. Instead the license to use the "Sinclair" name and "ZX Spectrum" trademark was granted to SpecNext Ltd. by the owner of the trademarks in exchange for a charitable donation to the Royal National Institute of Blind People[citation needed].


The Next started life in 2010 in Brazil, as a variant of the TK95 Spectrum clone. In 2016 Victor Trucco and Fabio Belavenuto announced the "TBBlue" board, named after the two creators and the colour of the solder mask of the motherboard, a bare circuit board implementation of the product for advanced hobbyists.

With the help of Henrique Olifiers the duo wanted to export the TBBlue to the UK, the ZX Spectrum's original home, having received moderate success with the board in Brazil.[5]

The Next was first announced as a distinct product in 2016 after the participation of original Spectrum industrial designer Rick Dickinson was secured. A crowdfunding campaign was launched on the Kickstarter platform in January 2017 with an initial funding goal of £250,000.[6] At the end of the campaign 3,113 backers pledged £723,390. While the campaign was successful in creating a userbase for the new platform, it wasn't a commercial success. Due to what campaign creators call "bad tax advice" the production of the machines ended up causing costs instead of revenue to the creators.[7]

Although initially intended to use the original ZX Spectrum's Z80 chip[8], the design was altered to use the Xilinx Spartan-6 FPGA[9], to allow "hardware sprites, scrolling, and other advanced features to be incorporated within the machine itself".[4]

The board-only computer was delivered to backers in December 2017[10]. After some design and production delays, the first batch of finished units were delivered to backers in March 2020.

A second Kickstarter launched on 11 August 2020 at 21:00 BST and reached 100% funding (£250,000) within six minutes (at least one report claims four minutes[11], while the project creator claims five minutes[12]). This performance earned it coverage from BBC News [13]. The campaign passed 400% funding (£1,000,000) on 14 August 2020[14].


Four models of the Next were produced in the first Kickstarter[15]:

Overview of the Next Issue 1 models
Model name Cased real-time clock installed Wi-Fi installed Raspberry Pi Zero "Accelerator" installed Board revision Notes
ZX Spectrum Next developer board No No No No 2A Only board revision which can fit in an original, modified, ZX Spectrum case
ZX Spectrum Next Yes No No No 2B Does not require modification, with a capacitor, to eliminate electronic "noise"[16]
ZX Spectrum Next Plus Yes Yes Yes No 2B
ZX Spectrum Next Accelerated Yes Yes Yes Yes 2B Accelerator will enable loading compressed tzx tape images from SD-card and provide emulation of the MOS Technology 6581 SID soundchip.

All models include 1024 kb RAM (768 kb free) and can be upgraded by the owner;

  • Adding two 512 kb chips brings the RAM to 2048 kb.
  • An internal "beeper" speaker can be installed.
  • Any of the higher models' optional extras can be installed.

The second Kickstarter offers just two models[17], though at the time of writing their details are being amended as the funding reaches "stretch goal" targets[18];

Overview of the Next Issue 2 models
Model name Raspberry Pi Zero "Accelerator" installed Notes
ZX Spectrum Next Plus No Wi-Fi module relocated to avoid audio interference
ZX Spectrum Next Accelerated Yes

Both models are cased, include a real-time clock, Wi-Fi, and 2048 kb RAM, use board revision 2C, and can be upgraded by the owner;

  • An internal "beeper" speaker can be installed.
  • A Raspberry Pi Zero unit can be installed as an "Accelerator" into the Next Plus.

All models feature a ZX Spectrum compatible expansion bus and c-cassette tape input/output ports, enabling existing ZX Spectrum peripherals, such as microdrive units and printers to be used with the Next. In addition the machine has built-in DivMMC-compatible SD card support, two Kempston/Sinclair joystick ports and a PS/2 style mouse connector.


The Next has received generally favorable reviews in the specialist press. In the official Raspberry Pi magazine "MagPi", Lucy Hattersley called it "a lovely piece of kit", noting that it is "well-designed and well-built: authentic to the original, and with technology that nods to the past while remaining functional and relevant in the modern age".[9]

In PC Pro magazine, columnist Gareth Halfacree called the Next "undeniably impressive" while noting that the printed manual lacks an index, and that some features are "not quite ready".[19]

Retro Gamer featured an 8-page interview with the creators of the machine about the highs and lows of creating a "true successor to the much-loved Sinclair micro".[5]

Clones and emulatorsEdit

The Next team actively encourages the manufacture of clone machines to promote and expand the userbase as much as possible.

Clones of the Next include;

  • ZXDOS+ (board) / gomaDOS+ (board with case)
  • A ZX Next/TBBlue Clone

Emulators of the Next include[20];

  • ZEsarUX by Cesar Hernandez[21]
  • #CSpect by Mike Dailly[22]

Visual DesignEdit

The Next's case design[23] is by Rick Dickinson who designed the original 48K Spectrum and Spectrum+, but died during the development of the keyboard of the computer.[24] It takes design cues from the Spectrum+ and Spectrum 128, not the later Spectrum +2 or +3 manufactured by Amstrad.

Operating System and softwareEdit

The default operating system of the Next is NextZXOS. The operating system provides a graphical file browser and menu based access to Next features. In addition the machine has extended BASIC interpreter NextBASIC, with commands and features added to support the capabilities of the Next, such as support for 9 channel AY-sound and built-in sprite graphics editor. The NextZXOS and NextBASIC are both released under Open/Closed-Source hybrid license called "The Next License", with all parts of the OS being Closed Source by default, unless explicitly placed under Open Source MIT License. The Next License prohibits selling the software and charging a duplication fee for it, but cost-free distribution is allowed under CreativeCommons Attribution/ShareAlike license. The OS and BASIC can be found from GitLab.

NextZXOS and NextBASIC were written by Garry Lancaster, and the machine is provided with printed manual covering the OS and BASIC in detail. The manual was upgraded to full colour print after the second kickstarter campaign reached £700000. The manual is also available on-line at https://www.specnext.com/zx-spectrum-next-user-manual-first-edition.

In addition to it's own native OS, the Next is able to run prior versions of Sinclair BASIC, such as 48K Basic and 128K Basic. Next is the first machine under Sinclair brand that is also able to run CP/M operating system. Due to licensing reasons, CP/M doesn't come bundled with the machine, but has to be downloaded separately. Although this does potentially open a sizeable software library of CP/M to the Next users, it is worth noting that CP/M cannot take advantage of the Next's advanced capabilities, such as large memory. CP/M software also in general tends to be rather old and perhaps outdated for most purposes.

Hardware SpecificationsEdit

Overview of the Next hardware specifications
Aspect Issue 1 revision boards (2A, 2B) Issue 2 revision board (2C)
CPU Z80N (Zilog Z80 compatible with additional instructions) implemented in FPGA TBC
Speed 3.5, 7, 14 or 28 MHz TBC
RAM (Memory) 768K (base), 1792K (expanded) TBC
Graphics From 128 × 96 to 640 × 256 pixels TBC
Colour Depending on mode and layer, 16 or 256 colours. No colour clash in certain modes. TBC
Sprites Up to 128 hardware sprites of 16 × 16 pixels. TBC
Sound Traditional "Beeper", 3 × General Instrument AY-3-8910 programmable sound generators, and 4 × 8-bit DACs implemented in FPGA TBC
Software NextZXOS Operating System + NextBASIC. TBC
Connectivity Tape in/out, Audio out, HDMI, VGA, 2 x Kempston/Sinclair joystick connectors, PS/2 mouse port, ZX Spectrum compatible expansion bus TBC

Other recreations and emulationsEdit

The Next can be used to recreate a number of other computers such as the Acorn BBC Micro, as long as their hardware will "fit" into the FPGA[25]. These recreations are known as "cores". The machine can also be made to boot directly into an alternative core. While the use of alternate cores is supported, the cores themselves are unofficial third-party projects. Among the notable collections of cores is GitLab repository Victor Trucco: ZX Spectrum Next Cores.

A selection of 8-bit arcade machines can be emulated with Rusty Pixels's RAMS (Rusty Arcade MachineS), a Next program, as long as the user has the arcade machine's ROM data.


  1. ^ Cadwallader‎, ‎Mike. "From my records, we made 3010 cased computers". Facebook. Retrieved August 14, 2020.
  2. ^ Bush, Steve (April 28, 2017). "ZX Spectrum rides again, with Z80 and optional Raspberry Pi Zero". Electronics Weekly.
  3. ^ Beschizza, Rob (April 30, 2017). "ZX Spectrum Next is an advanced version of the original 8-bit monster machine". BoingBoing.
  4. ^ a b Crooks, David (December 2019). "ZX Spectrum Next Raspberry Pi project showcase". MagPi Magazine.
  5. ^ a b Carroll, Martyn (January 15, 2020). "The Next Level - Introducing the ZX Spectrum Next". Retro Gamer (UK).
  6. ^ "Celebrate the Sinclair ZX Spectrum's 35th anniversary with… yet another retro console". Metro (UK). April 24, 2017.
  7. ^ "ZX Spectrum reboot promising – steady now – 28MHz of sizzling Speccy speed now boasts improved Wi-Fi". The Register. August 13, 2020.
  8. ^ Ridden, Paul (April 24, 2017). "Home computing classic reborn as ZX Spectrum Next". New Atlas. Retrieved August 13, 2020.
  9. ^ a b Hattersley, Lucy (April 2020). "ZX Spectrum Next Accelerated review". MagPi Magazine.
  10. ^ "Update 24: What's next for the Next (including full computers shipping estimate) · ZX Spectrum Next". Kickstarter. Retrieved August 13, 2019.
  11. ^ "Opvolger ZX Spectrum Next krijgt snellere cpu-modes en meer ram". Tweakers. August 12, 2020.
  12. ^ Olifiers, Henrique. "We Got Funded at 28MHz!". Kickstarter. Retrieved August 13, 2020.
  13. ^ "ZX Spectrum Next Issue 2 blasts through Kickstarter goal". BBC News. August 13, 2020. Retrieved August 13, 2020.
  14. ^ Bagley, Jim. "£1,000,161 thanks everyone". Facebook. Retrieved August 14, 2020.
  15. ^ "ZX Spectrum Next - Issue 1: Campaign". Kickstarter. Retrieved August 13, 2020.
  16. ^ Olifiers, Henrique. "Next Board 2A Capacitor Mod". ZX Spectrum Next. Retrieved August 13, 2020.
  17. ^ "ZX Spectrum Next - Issue 2: Pledge". Kickstarter. Retrieved August 13, 2020.
  18. ^ "ZX Spectrum Next - Issue 2: Stretch Goals". Kickstarter. Retrieved August 13, 2020.
  19. ^ Halfacree, Gareth (July 2020). "ZX Spectrum Next". PC Pro Magazine (UK) (309). pp. 48–50.
  20. ^ "Emulators". SpecNext official Wiki. Retrieved August 14, 2020.
  21. ^ Olifiers, Henrique. "ZEsarUX: Next emulator". ZX Spectrum Next. Retrieved August 14, 2020.
  22. ^ Dailly, Mike. The life of a Games Programmer http://www.cspect.org/. Retrieved August 14, 2020. Missing or empty |title= (help)
  23. ^ https://www.flickr.com/photos/9574086@N02/albums/72157685519763101
  24. ^ Halfacree, Gareth (April 26, 2018). "Industrial designer Rick Dickinson passes away". Bit-Tech.Net.
  25. ^ Dokos, Phoebus (April 27, 2020). "Multiple FPGA Cores Support". ZX Spectrum Next. Retrieved August 13, 2020.

External linksEdit