Sinclair ZX Spectrum 30th Anniversary

The ZX Spectrum is 30 years old. Sinclair ZX Spectrum 30th Anniversary is today. Happy birthday Spec. ZX Spectrum, the microcomputer launched in 1982 by Sinclair Research (Cambridge, UK) is seen by many today as the inspiration for a generation of eager young programmers, software and game designers in the UK. It has inspired many people also outside UK, including me. My first computer was Sinclair ZX spectrum. The successor to Sir Clive Sinclair’s ZX81 – at the time the world’s best selling consumer computer – it introduced colour “high resolution” graphics and sound. The design was sleeker than anything else on the market and price was good too. That allowed adverts at the time to boast: “Less than half the price of its nearest competitor- and more powerful”. ZX Spectrum’s chief designers reunited 30 years on article gives some background how this computer was created. Read also Happy 30th Birthday, Sinclair ZX Spectrum – The story of an historic micro.


I remember starting my ZX Spectrum computing 1983 by first playing Jetpac game that was cool game at the time (check Jet Pack remake for web browser if you want to try). I remember playing that game so much that quite shortly I broke down the keyboard because of too much playing. After some time I started programming, first with built-in Basic. Later also Assembler (the manual had the assembler commands and their coded listed on the end which was cool) and some other languages. Then I did also some hardware hacking, including installing a better keyboard and adding my own joystick interface to it (my own design compatible with Interface 2 joysticks). It 80′s was fun hacking time.


  1. Tomi Engdahl says:

    ~10 euros ZX Spectrum Emulator [eng subs]

    [Update] Added 128K sound, .Z80 format, 4:3 / 16:9 aspect ratios, microSD card.

    For about 10 euros, you could have a ZX Spectrum emulator on a ESP32 based board. No need for complicated pins or soldering, just connect an VGA monitor and PS/2 keyboard.

    You will need to load the emulator software (available on a GitHub repository) and the desired games (in SNA format).

    Emulation speed has been adjusted for code in repo _after_ making of this video.

    Spectrum 48K / 128K / +2 / +3 emulation modes supported.

    Supports Wiimote (v1) controller as control method (see repository documentation and/or my previous video about Spectrum emulation on ESP32).

    We will need the Visual Studio Code development environment with the PlatformIO extension, but the steps to follow are simple.

  2. Tomi Engdahl says:

    The ZXBOX Sinclair ZX Spectrum Emulator Machine Fully Loaded (Rasp Pi Zero) 48k 128k 128k +3

  3. Tomi Engdahl says:

    Restoring a mouldy ZX Spectrum micro computer from the ’80s

  4. Tomi Engdahl says:

    ZX Spectrum Game Loader Has Joystick Pass-Through
    TZXDuino is hardware for loading software onto vintage computers, and JamHamster built a version with a joystick pass-through.

    Today, you can load software onto vintage computers by playing the right audio file from a digital source, like a smartphone. TZXDuino is a dedicated hardware device for the job, and JamHamster built a version with a joystick pass-through.

    A TZXDuino is a small Arduino Nano-based device that pumps selected program audio files out to vintage computers, such as the legendary ZX Spectrum.

  5. Tomi Engdahl says:

    CSS Electronics’ ZX Nucleon Is an Eight-Bit Clone-of-a-Clone Designed with Russian Software in Mind
    Cloning the Pentagon, which cloned the ZX Spectrum, the ZX Nucleon runs “the best-quality software [from] the countries of the ex-USSR.”

  6. Tomi Engdahl says:

    In his video, [Keith] goes to great lengths detailing the impact that Roger Dymond had on the early home computing scene. After being let go from his council apprenticeship, Roger turned his attention to developing games for the ZX81, and later the ZX Spectrum. With the help of his family, he went on to run a moderately successful mail-order games publishing venture for several years. Increasing advertising costs and a crowded development scene saw Roger’s business become nonviable by 1983, but not before developing several gambling-style games and a standout Space Invaders clone.

  7. Tomi Engdahl says:

    Home computing pioneer Sir Clive Sinclair dies aged 81

    Creator of the landmark ZX Spectrum and the less commercially successful C5 died after a long illness

    Sir Clive Sinclair, the inventor and entrepreneur who was instrumental in bringing home computers to the masses, has died at the age of 81.

    His daughter, Belinda, said he died at home in London on Thursday morning after a long illness. Sinclair invented the pocket calculator but was best known for popularising the home computer, bringing it to British high-street stores at relatively affordable prices.

    Many modern-day titans of the games industry got their start on one of his ZX models. For a certain generation of gamer, the computer of choice was either the ZX Spectrum 48K or its rival, the Commodore 64.

    His first home computer, the ZX80, named after the year it appeared, revolutionised the market, although it was a far cry from today’s models. At £79.95 in kit form and £99.95 assembled, it was about one-fifth of the price of other home computers at the time. It sold 50,000, units while its successor, the ZX81, which replaced it, cost £69.95 and sold 250,000.

    In 1982, he released the ZX Spectrum 48K. Its rubber keys, strange clashing visuals and tinny sound did not prevent it being pivotal in the development of the British games industry. Much-loved games – now in colour – that inspired a generation included Jet Set Willy, Horace Goes Skiing, Chuckie Egg, Saboteur, Knight Lore and Lords of Midnight.

    Sinclair became a household name as his products flew off the shelves and was awarded a knighthood in 1983.

    The Sinclair TV80, a pocket TV, was another device, like the C5, that did not catch on, although people now regularly view programmes on their mobile phones. And although they do not look like the Sinclair C5, which later acquired cult status, electric vehicles are, of course, all the rage today.

  8. Tomi Engdahl says:

    Ferranti’s Ghost Tours The Chip Factory That Made The ULA

    Former Ferranti Electric engineer [Martin Mallinson] recently posted a 1980s documentary on YouTube (see the video below the break). It shows in some detail the semiconductor plant at Gem Mill outside of Manchester UK, as seen through the eyes of the ghost of founder Dr. Sebastian Ferranti. This dramatic device seems a little silly at times, but the documentary still provides a very interesting look at the industry at the time.

    The Gem Mill plant was one of the first semiconductor facilities, having begun operations in the 1950s by Ferranti. In 1959 they made the first European silicon diode, and went on to commercialize Uncommitted Logic Arrays (ULA) in the early 1980s. Most famously, Ferranti ULAs were used in many home computers of the day, such as the Sinclair ZX81 and ZX Spectrum, Acorn Electron, and the BBC Micro. Much of the factory tour in this documentary is depicting the ULA process, and they hint at an even more advanced technology being developed by the (unnamed) competition — an FPGA? CPLD?

  9. Tomi Engdahl says:

    A Redesigned ZX Spectrum Desktop Computer That Works Surprisingly Well

    What if – The ZX Spectrum Desktop / OPC (One Per Child) Design and build.

  10. Tomi Engdahl says:

    In the ’80s, spaceflight sim Elite was nothing short of magic. The annotated source code shows how it was done
    Load new commander (Y/N)?

  11. Tomi Engdahl says:

    When A Single Bit Was Enough, Into The Sound Of The ZX Spectrum

    For Sir Clive Sinclair the 1-bit audio must have been welcome as it removed the need for an expensive sound chip and kept the Spectrum to its low price point, but on the face of it there was little more it could do than create simple beeps using Sinclair BASIC’s built-in BEEP command. The video gives us an in-depth look at how interleaving and PWM could be used to create much more complex sounds such as the illusion of multiple voices and even sampled sounds.

    Understanding Computer Sound. 5. ZX Spectrum

  12. Tomi Engdahl says:

    Sinclair’s Wonder – The Science of Cambridge MK14

    In the United Kingdom in the late 1970s, times were tough. Buying a computer was simply unaffordable for many families. Enter Clive Sinclair, with an assist from Ian Williamson. A consummate engineer – Clive’s company, Science of Cambridge, came up with a simple, but complete single board computer based on the National Semiconductor SC/MP microprocessor. Offered for just 39 pounds, the new computer opened the door to home computing for millions.

  13. Tomi Engdahl says:

    A ZX Spectrum? In a cassette? “Yes”.

    ZX Spectrum Raspberry Pi Cassette

    Stuart Brand was between jobs and decided to concentrate on pushing his skills by building Raspberry Pi projects: “I headed to the garage and embraced my inner nerd!” exclaims the maker of the ZX Spectrum Raspberry Pi Cassette. “I wouldn’t have had a clue how to build any of this stuff before lockdown. It goes to prove that you never know what you’re capable of until you give it a go.”

  14. Tomi Engdahl says:


    This isn’t a throwback. If nothing, it’s actually a throw-forward. Designed to show how far we’ve come in a span of 4 decades, this cassette has a fully-functioning Raspberry Pi computer inside it running a ZX Spectrum emulator inside it.

    Stuart would write programs on the ZX Spectrum and store them on cassette tapes. 40 years later, the entire ZX Spectrum computer can practically fit inside the same cassette’s plastic body, with a few minor adjustments made to allow the parts and ports to line up perfectly.

    The 5mm interior of the cassette meant Stuart had to hack together his solution. To ensure that the PCB of the Raspberry Pi Zero W didn’t end up peeking out through the cassette’s two holes, he ended up carving out a portion of the PCB, ensuring the illusion was complete. Thankfully, this didn’t affect the functionality of his computer. “I lost some GPIO ports, but it was well worth it to get the tape looking right.”

  15. Tomi Engdahl says:

    ZX Spectrum – 40th Anniversary Restoration – 4K

    For the ZX 40th Anniversary I created a restoration and hardware history video going over this mighty computer which became Britain’s best selling microcomputer.

  16. Tomi Engdahl says:

    ZX Spectrum’s 40th Anniversary! | Documentary

    This year is the 40th anniversary of the release of the Sinclair ZX Spectrum. In this episode of Computers Like These, we go behind the wall of history to explore how and who and why someone made the ZX Spectrum computer.

  17. Tomi Engdahl says:

    ZX Spectrum | Cheap as Chips

    Update: The Spectrum is repaired, but all it took was some new capacitors before I attempted any interesting fault finding. So this series will now be taking a different direction exploring what made the system unique.

  18. Tomi Engdahl says:

    ZX Spectrum | Ghetto Graphics & Colour Clash

    Today we’re focusing on the distinctive graphical style the ZX Spectrum had, including the famous colour clash, why it looked like this, and how game designers overcame the limitations.

    3D functions in BASIC (ZX Spectrum)

  19. Tomi Engdahl says:

    ZX Spectrum – Four layer smooth parallax scrolling from a short BASIC type-in?

    Still tweaking my BASIC scrolling technique.
    This one is simplified to work with just 8 UDG, rather than 16. Next job is a version that auto-generates / pre-shifts 16 UDG scenery.
    The listing in this video won’t run on a 16k Speccy. Only because I was avoiding the use of USR.
    It would take a few seconds to fix :)

  20. Tomi Engdahl says:

    Timex Sinclair 2068 – The American ZX Spectrum

    This was the last Sinclair computer sold by Timex in the USA, but it was not the last Sinclair computer sold in the USA — Sinclair Research in Nashua, NH sold a U.S. version of the Sinclair QL via mail-order in 1985, although obviously it was another failure in the marketplace. Sir Clive’s Cambridge Z88 portable computer was also sold here and was somewhat more successful.

    There’s something incredibly cool about playing a wave file on a modern laptop and having an old computer able to load a game from that.

    You know what’s cool? Since every ZX Sprectrum software is stored in a sound file, this means that you can load a game from pretty much anything. Phone? Yes. Computer? Yes. Walkman? Yes. Kinda cool ngl.

  21. Tomi Engdahl says:

    ZX Spectrum – Bad Video Repair

    In this video I repair a ZX Spectrum with bad video output caused by a faulty transistor.

    I bought this Spectrum a couple of months ago, and had been waiting for replacement parts to arrive before making this video.

    Apologies for some of the camera work in the soldering portions of the video, my face was right next to the camera, and I wasn’t using a separate microphone. I’ll be trying to do this better next time.

    I’m very much an amateur at all of this, so any tips or suggestions are always appreciated.

  22. Tomi Engdahl says:

    Pico ZX Spectrum 128K Is a Recreation of the Sinclair Classic Computer
    Powered by a Pi Pico and surrounded by a beautiful circuit board enclosure.

    The latest enclosure-less computer design from Peter “bobricius” Misenko is the Pico ZX Spectrum 128K. And as its name suggests, it emulates the 8-bit ZX Spectrum 128K using a Pico Pi with modern interfaces.

  23. Tomi Engdahl says:

    8 Games That I Think Are Better On The ZX Spectrum Than The C64! | Retro Or Bust!

    Growing up, I had a Commodore 64 & my mate had a ZX Spectrum and I hated the Spectrum! 30 years later, I get a Spectrum & find that some games are actually better than on the C64…..

  24. Tomi Engdahl says:

    Clever engineering on a budget – ZX Spectrum Interrupts

    How clever engineers made a cheap computer powerful

    How do you make an underpowered 8 bit CPU seem a bit more capable than it really is? Interrupts! that mechanism where the CPU can be poked and told to do something completely different, then resume whatever it was originally doing as if it’d never stopped.

    On the Spectrum – and in this instance I mean the original 16K Spectrum – this was done in a typical Sinclair way – cheaply, with as few components as possible, leaving the majority of the work to the programmer. I’m sure Sinclair HQ must have had a sign on their wall saying “if you can do it in software, we can build it cheaper” or something.

    Let’s look at how those devious hardware designers crafted a cheap and functional system that didn’t exactly follow the Z80 specs.

    You see the Spectrum was made to be cheap, like super cheap. Cheaper than any other home micro. And unlike cheap computers of the time, it was designed to be a usable computer.

  25. Tomi Engdahl says:

    The Spectrum Show EP 121

    It’s the new series!
    In this episode I look at the Konix Liberator interface.
    I review Ninja Spirit, Rally Driver and Beethoven’s Revenge.
    Geoff and I chat about extras in games and in a new multi-part feature I try to run a business using the Spectrum.

  26. Tomi Engdahl says:

    The Great Escape Walkthrough, ZX Spectrum

    A walkthrough of the ZX Spectrum game, The Great Escape. For more ZX Spectrum walkthroughs, go here:

  27. Tomi Engdahl says:

    Cloning Cobra, a Romanian Computer That Cloned the Spectrum 48K
    This design uses period-correct components to clone a clone!

    During the eight-bit computer era, it was commonplace for engineers (and hackers) in European countries to sell clones of computers from other regions. For example, Cobra was a Romanian clone of the Spectrum 48K with a few improvements. In the late 1980s and 1990s, students often built their own version of the Cobra design — clones of clones! Drawing on their inspiration, Thomas Sowell set out to clone the Cobra.

    The original Spectrum 48K had a Z80 microprocessor running at 3.5 MHz with either 16K or 48K RAM. It could draw bitmap graphics and make beeper sounds.

    Cobra had a similar base design with a mod available to increase the RAM to 80K. It also added a floppy disk interface. That addition, plus enabling additional address modes for the Z80, meant that Cobra could also run CP/M software. (CP/M was a prevalent cross-machine operating system at the time.) However, unlike the Spectrum 48K, Cobra did not have a ULA. Instead, an array of 7400-series logic chips implemented the 48K’s ULA functions.

    As Sowell notes in his blog, it is rather remarkable that people were even able to reverse engineer the ULA, and overall Spectrum design, without (decent) oscilloscopes or logic analyzers!

  28. Tomi Engdahl says:

    The Z80′s secret feature discovered after 40 years!

    For years, it’s generally accepted that 8 bit microcomputer CPUs does not have hardware support for protected mode. However, my recent discovery shows otherwise. In this video, I will show you how to implement memory and I/O protection on a z80 with minimal external circuit.

    0:00 The Z80 has a protected mode
    0:32 Literally the worst intro video ever
    0:52 What is Z80
    1:52 Why is protected mode important?
    3:10 Undocumented? Really?
    4:10 How to implement protected mode
    10:34 Final Conclusion
    12:10 Clickbait?
    12:54 Applications of the protected mode
    14:27 An interesting story

  29. Tomi Engdahl says:

    Yesterday’s Future Is Brighter Today

    The demoscene never ceases to amaze. Back in the mid-80s, people wouldn’t just hack software to remove the copy restrictions, but would go the extra mile and add some fun artwork and greetz. Over the ensuing decade the artform broke away from the cracks entirely, and the elite hackers were making electronic music with amazing accompanying graphics to simply show off.

    Looked at from today, some of the demos are amazing given that they were done on such primitive hardware, but those were the cutting edge home computers at the time. I don’t know what today’s equivalent is, with CGI-powered blockbusters running in mainstream cinemas, the state of the art in graphics has moved on quite a bit. But the state of the old art doesn’t rest either. I’ve just seen the most amazing demo on a ZX Spectrum.

    Elysium State by Stardust (final version)

    Release date: 04-12-2022
    Release party: CAFePARTY2022
    Compo: ZX Spectrum Demo
    Platform: ZX Spectrum
    Ranked: 1st


    Elysium State by Stardust
    rollerbob – kowalski – diver – n1k-o – sq – psndcj

    Phew! After one month and a few days we havefinally made a final version of this demo!

    It took us too long to make all the fixes we wanted and needed, and we know that, so, sorry and that’s why here is the brief list of the changes:

    - Autodetects and fixes for the most common ZX models (128K/+2/+2a/+2b/+3 and Pentagon)
    - Some bugs were fixed
    - Sync was improved a lot in almost every part
    - Some parts were refactored for stable working
    - Pictures and effects were polished a bit
    - New credits screen was added
    - A lot of small details were fixed and updated

    Although Elysium State should work properly on all classic machines, it makes heavy use of our custom Beta Disk trackloader. Thus it’s quite impossible to make a .tap version not ruining the whole demo flow. So you would need to have Beta Disk interface or DivMMC to run the demo. Sorry for that.

    Please also note that the “Selfie Girl” part may look strange on some hardware or emulators due to inaccurate timings emulation (e. g. Fuse) or inner hardware processing pecularities (e. g. ZX Evolution). In some cases this could be circumvented, but we decided to leave it as it is.

    During our tests, we found a flaw in the WD1793/VG93 emulation on ZX Evolution/Baseconf, due to which the demo didn’t run from the SD card, but worked fine with real disk drives (and Gotek). We have informed the authors and the flaw was immediately fixed in the latest firmware. So, if this demo doesn’t run on your ZX Evolution/Baseconf, please update your firmware to the latest version.

    And at the end as the most important thing we desperately want to say our HUGE thanks to the following people we adore and respect:

    - iq (Inigo Quilez) for kindly permission to use his incredible Selfie Girl picture: (yes, it’s a tribute to that amazing shader!)
    - rook and wbcbz7 from SibCrew for competition and supporting around
    - personally wbcbz7 for bughunting and on a real machine
    - introspec for helping with model detection and interrupt alignment routines
    - savelij/NedoPC for quickly fixing the firmware
    - jtn/4d for testing on a real machine
    - Ized/Quite for support
    - George Patsouras for original “Medusa” picture
    - Oxygene for STNICCC2000 (yes, you recognized it right!)
    - nodeus for helping with video capture
    - CAFePARTY organizers and visitors for such a great party
    - And you for the patience in waiting this one!


  30. Tomi Engdahl says:

    ZX Spectrum Turned Into A USB Keyboard

    ZX Keyboard

    An Arduino based project to convert an old broken ZX Spectrum computer in to a USB keyboard.

  31. Tomi Engdahl says:

    Recreating The ZX Spectrum Unboxing Experience By Manufacturing A New Boxed One

    Why scour the internet for a rare-as-hen’s-teeth new in box ZX Spectrum computer when you can instead order up some parts, assemble a basically all new ZX Spectrum along with the box, instruction manuals and more?

    Why scour the internet for a rare-as-hen’s-teeth new in box ZX Spectrum computer when you can instead order up some parts, assemble a basically all new ZX Spectrum along with the box, instruction manuals and more?
    Building a new ZX Spectrum from all new parts

    This series of posts will be documenting my quest to building a ZX Spectrum using as many still available parts as possible, I am not sure yet if it’s completely possible, but due to the work of people like Charlie Ingley who created a brand new replacement ULA chip, I am feeling confident.

    I was going to redraw the board and get it printed, however my initial research alerted me to these reproduction Issue 3B boards available on PCBWay from PABB – the Issue 3B board was the most common board for the 48k Spectrum, and is a good place to start.

  32. Tomi Engdahl says:

    Building a brand new ZX Spectrum with nearly 100% new parts, reconstructed box, manuals & tape

    I grew up with the Spectrum but never actually unboxed one, this is an attempt to build not only a Spectrum from completely new parts, either still manufactured, modern replacements or modern recreations such as the vULA but also the box, manuals, tape and everything else you would have come home with in 1984.

    00:00 Intro
    01:39 PCB
    02:19 The Resistors
    05:47 The Capacitors
    06:32 Diodes
    07:05 Transistors
    07:29 Crystals
    08:01 Mic and Ear Ports
    08:26 Sockets
    09:55 Chips
    11:03 Speaker
    11:10 Video
    12:13 Jumpers
    12:59 Initial Tests
    14:06 Case
    15:59 Post Build Tests
    17:57 Manuals
    20:22 Horizons Tape
    26:25 The Box
    27:47 Final Thoughts

  33. Tomi Engdahl says:

    ZX Spectrum | The Six Most Important Games

    ZX Spectrum | The Six Most Important Games Sinclair Research Ltd. released the ZX Spectrum, an 8-bit personal home computer, in the United Kingdom in 1982. The Spectrum was one of the first mainstream home computers in the United Kingdom, comparable to the Commodore 64 in the United States. The advent of the ZX Spectrum resulted in a surge in firms developing software and hardware for the system, and some credit it with launching the UK IT industry. Head Over Heels, Jet Set Willy, Skool Daze, Renegade, R-Type, Knight Lore, Dizzy, The Hobbit, Way of the Exploding Fist, and Match Day 2 were amongst the top 10 ZX Spectrum games.

  34. Tomi Engdahl says:

    A Pico-Based ZX Spectrum Emulator

    The ZX Spectrum was a popular computer of the 8-bit era. Now, it’s possible to emulate this machine on a microcontroller so cheap that it’s literally been given away on the front cover of magazines. Yes, we’re talking about the Pico ZX Spectrum project.

    The project consists of all the necessary code to emulate a ZX Spectrum upon the hardware of the RP2040 microcontroller that makes up the Raspberry Pi Pico. The community has then taken this code and run with it, using it as the basis for all manner of different ZX Spectrum builds. If so desired, you can go barebones and use the Pico to run a ZX Spectrum off a breadboard with HDMI video output. Alternatively, you can build something like the PicoZX from [Bobricius]. The handheld computer features a PCB-based housing, along with an LCD and an integrated keyboard. Other configurations support features like USB keyboards, VGA outputs, and working sound output.

  35. Tomi Engdahl says:

    Unless you were lucky enough to be able to afford a floppy disk drive, you probably used cassette tapes to store programs and data if you used pretty much any home computer in the 1980s. ZX Spectrum users, however, had another option in the form of the Microdrive. This was a rather unusual continuous-loop mini-tape cartridge that could store around 100 kB and load it at lightning speed, all at a much lower price point than a floppy drive….

  36. Tomi Engdahl says:

    Derek Fountain’s Stringy-Floppy-Free Sinclair ZX Microdrive Is Powered by Three Raspberry Pi Picos
    An unreliable but much-loved piece of 1980s data storage technology lives on in this open-hardware solid-state alternative.

  37. Tomi Engdahl says:

    My first computer as a childhood. Sinclair ZX spectrum. So many memories.


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