Games That Push the Limits of the ZX81

#Pushingthelimits #ZX81
No colour, no sound, no joystick port, the ZX81 was not made for gaming, but somehow it still became popular games machine. I talk a stroll down lack of memory lane and uncover some games that pushed the limits of this machines tiny capabilities.
Embusca Dos Tesouros (In Search of Treasures)
www.embuscadostesouros.com.br/
muriloq.com/ebdt/ebdt-en.html
The first site is in in Portuguese but Google Translate does a good job.
The second site has downloads for both the original game and a hacked version with infinite lives.
Games Featured:
1K Chess
spectrumcomputing.co.uk/index...
3D Monster Maze
spectrumcomputing.co.uk/index...
Forty Niner
spectrumcomputing.co.uk/index...
Rocket Man
spectrumcomputing.co.uk/index...
Em Busca dos Tesouros
muriloq.com/ebdt/ebdt-en.html
Against the Elements
www.fruitcake.plus.com/Sinclai...
Nohzdyve
spectrumcomputing.co.uk/index...
Q-bert
sinclairzxworld.com/viewtopic...

[@Distinctly.Average]

Does anyone ever remember the ZX81 playing music of sorts? I do. It was a brilliant bit of lateral thinking. What you had to do was slightly off tune your TV then run the program with the volume up. Because of the way TVs worked back then, interference created different sounds. So by changing the image on the screen you could change the buzz from the interference. One chap wrote code to play about 15 different tunes. Just brilliant

[@scality4309]

Richard used to do this. The window licker dude.

[@kensukadventures628]

yes i wrote into a magazine about that, not sure if it ever got published in the letters pages.

[@robsawalker]

Yep, using the fast and slow commands.

[@Colt45hatchback]

Not on this, but i do remember that "feature" on the atari 2600, hes multi cart games often had some sound noise in their menu

[@jasonross6727]

Reminds me of HAX on the PDP-1.

[@supertouring22]

This little machine triggered my 30+ year career in IT. Fond memories.

[@ksportz66]

And kids today would never understand how you adjusted the volume on your tape recorder to get perfect Black/White stripes on TV while loading from tape.

[@robintst]

Never played 3D Monster Maze in my life but, come on, look at that... that is straight up survival horror. Even in it's very simple nature, it nails what makes horror effective: The unseen. The tension of the T-Rex hunting for you and all you get for feedback is messages at the bottom is why it works so well. He's around you somewhere and you don't know where or when he'll get you. The minimalist visuals also means your imagination fills in the blanks which compounds the feeling of tension.

[@jaysinha0]

3d monster maze scared the c r a p out of me with jump scares.

[@widearchshark3981]

It was the first game I ever played on the ZX81. And it was TERRIFYING! Getting away from the T-Rex was near impossible (but not impossible).

[@binarydinosaurs]

One of the best games ever. These days I laugh more than jump but there's still the occasional YARG when I get chomped.

[@davekendall5273]

I was surprised at how easy it is to avoid the T-Rex when playing 3D Monster Maze on an emulator. I remember it being really panic inducingly challenging to escape after he'd spotted you on the actual ZX81. Looking back, I think a lot of the difficulty came from the ZX81's terrible keyboard. In the heat of the moment, watching the screen for the ominous words "REX HAS SEEN YOU", it was easy to slip off those flat buttons and waste precious seconds faffing around with the controls as Rex came closer.

[@CZ350tuner]

I had a plug in Memotech keyboard. That made life so much easier.

[@neilwilson5785]

I just freaked each time. It's like the first cinemas that showed the train coming, and audiences ran away,

[@fergusdenoon1255]

yeah, the pads sometimes weren't too responsive and lining up turns was an issue, not as much an issue as pressing too hard and the entire thing crashing.

[@BertGrink]

I think you should have included the game MAZOGS; I clearly remember seeing it for the first time, it was literally a jaw-dropping experience for me, seeing how fast those monsters were animated.

[@Nation1A1List]

Absolutely the best ZX81 game ever!

[@dennishatton1337]

@@Nation1A1List Yes, remember ordering Mazogs from a magazine in 1981. I would have included Sega's Frogger as well.

[@ByteRotation]

Definitely agree. Mazogs is a great game with it's comparatively huge sprites in a large scrolling maze which I had never seen before.

[@thirdstar9255]

Holy cow. These are amazing. I remember spending hours typing junk in from magazines, and could never imagine something like this on my Timex Sinclair. (I'm in the States) I think the most advanced game I had was some low res version of Centipede. I remember seeing Flight Simulator on an in-store display, and it blew my mind.

[@amckeown]

Still to this day I'm amazed at seeing how coders problem solved with these memory restrictions. True pioneers

[@minsapint8007]

Totally agree. They are legends. It was stunning to learn that the ZX81 could actually play thr user at Chess.

[@WaynesWorld69]

Wow. Bringing back so many memories! A time when computers themselves were interesting. A time when school lunch was a discussion about games played, typed in out of magazines or wanted asap. Those were the major concerns in life. I feel so old lol. Thanks for the video.

[@weon_penca]

3D Monster Maze was all about panic and adrenaline. Great, great game indeed, I don't know why weren't more versions for other computers.

[@theannoyedmrfloyd3998]

Programming for limited capability machines like the ZX81 aka Timex Sinclair 1000 or the Atari 2600 is a practice in artwork.

[@Mat-Ellis]

Amazed you didn’t include QS Defender, which was iirc the not only first hi-res game on the ZX-81 but also ran perfectly on the ZX-80 which was just grand for us paupers who had to make do with cast off ‘80s and couldn’t even afford a ZX81. Thanks for a big nostalgia trip!

[@gambini_modding]

I have a broken ZX81, my grandfather bought it loooong ago and tried to learn computer with it. He was going to throw it away because some keys weren´t working, but i took it and had it there for decades. I once detached the keyboard membrane thinking the problem would be there, just to later learn that the keys not working was a commonn issue related with the bottom of the case shortcutting the thermal isolator, or something like that. But at some point it didn´t work anymore. I dream with fixing it and fixing the tunner of an old black and white 12´ televisor i have and to play these games with them. I know the knowledge to solve those issues is down a long road, but I dont lose my hopes. Archaic analogic electronics have an irresistible charm for me. It´s so nice to know i am not alone!

[@joinedupjon]

good to see 3D monster maze again - It looks how I remember but it's surprising to believe how thrilling and immersive it seemed at the time. The other one I remember was Bomb BA ... which had its brief moment in the sun during the Falklands conflict.

[@kaminutter]

Brilliant video, it is amazing what you can do with text only machine when you can modify the character set. The ZX81 processor was in charge of generating the video signal while the ZX Spectrum had circuitry which did this instead allowing the processor to do other tasks. The difference in clock speed is not much at all - only .25 mhz I think.

[@wightmand]

Well done for including 1k Chess. Whilst its certainly not pretty it's no mean achievement fitting a viable chess program in < 1k (not unlike fitting Elite into

[@Sharopolis]

How could I miss that one?

[@347573]

That version was pretty limited in playing capabilities and was playing just a very limited version of chess. Still an achievement, but there is a newer implementation able to play the full FIDE rules (even under promotion) at decent strength. All still in 1k (and in fact much less since there are also system variables and screen memory inside it!). Pity that was not mentioned...

[@drivingmemad7640]

Hey, I'm from Portsmouth! How are you doing there, over the water? I did have tickets to the festival this year, so I may see the lovely island next year then (or the year after).

[@Electrozonelectronic]

Great memories and really well put together video. I loved my ZX81, learning Z80 machine code at about 14 to make my own games gave me the skills to make a good living doing something I enjoy. Clive Sinclair is a living legend!

[@robsawalker]

3D monster maze is one of the most significant games ever. It is an absolute masterpiece in 16K.

[@neillmitchell6470]

I spent I don't know how many hours playing Invasion Force back in the day. Still one of my favourite games. There's something about it that is just so compelling. Shows that simplicity is sometimes best!

[@speccysrule3678]

You missed out Sea Mines, a Hi-Res submarine game I played a lot in the 80's. And still play to this day. What a wonderful machine the ZX81 is.

[@BertGrink]

I haven't played that game myself (yet) but i do remeber that it was a type-in in Your computer.

[@kelpkelp5252]

Finally, found the complete opposite of the rising inflection.

[@chrismingay6005]

Recently stumbled upon your channel and I've been binge watching your Push The Limits content. Absolutely love it, thank you very much!

[@dorianeroars666]

Oh my God i was specificaly looking for a video about the Rocket Man and 49ers, a friend lend me a tape with these games, it just blow up my mind with the "high resolution stuff" ... so cherished memories ...

[@suprememasteroftheuniverse]

Your reading of Brazilian names is perfect.

[@cameralabs]

Excellent work! I now feel slightly unfaithful abandoning my 81 when the Spectrum arrived, so the best i ever saw from it was 3D Monster Maze...

[@ksportz66]

I wrote a program to print league tables (football , old 1st division) Had to poke some address to get bottom two teams on screen 😇

[@alittlepeaceandkarma]

My first computers were a ZX81 and then a Commodore 16. Now I retro game playing Spectrum games on my Chromebook.

[@BastetFurry]

TT GO VGA32 emulating a VC-20. A frigging sub 5€ microcontroller having software defined video, much like the ZX81, and emulating a whole computer. What a time to be alive...

[@Livinghighandwise]

Almost the same with me except the C64 was my second machine. The local Big Lots was closing down in my town in the early 80s and they had one last Z81 on clearance for about $80 which was a crapton of money for us at the time. I am in great dept to my parents today as both machines helped put me on track to a lucrative career in software development later in life.

[@becconvideo]

Impressive what the ZX81 is capable of. I remember a having played a single game (with some block graphic spiders) - but maybe I played the maze thing as well. I used my ZX81 mainly to learn to program in Basic and Z80 machine code. I even did so longer than necessary as the ZX81 comes with the VAL("x+y") function which allows to evaluate mathematical functions on the fly - nice for numerical algorithms. I still have my machine and most cassettes - probably they can still load somehow. (if I can find a tape working recorder and TV) - just to find the spider game and to see if I have the maze thing.

[@JimforbesRitte]

“(Lack of) memory lane” - priceless!

[@gabrielirlanda]

06:25 I love how the programmer used the V for the teeths and the O for his eyes, very clever. Amazing games, it's a pity I never had any game for that computer. 😢

[@ericdickison7995]

I remember playing Flight Simulator on my ZX81, it was great.........for its day..... Of course the Flight simulator on the Spectrum was infinitely better. Happy days!

[@bennypagesaunders6895]

Thanks for this trip down memory lane. I remember forty-niner. It was one of around 15 games I had for my (already) old zx81 in 1984. It was also the game that would never load, in hindsight probably down to a faulty cassette tape head alignment.

[@paulanderson7796]

Christmas Day 1981. I was eleven years old at the time. Magical.

[@antonnym214]

In 1981, I was 21. I didn't have a ZX-81, but I was programming professionally in Z-80 and 8080 Assembly. (Writing an inventory control program for hospitals to fit in 48K of RAM!) That Chess is amazing! The Z-80 was robust and luxurious, compared to its 8-bit competitor, the MOS 6502. Very nice video! I especially enjoyed Rocket Man and The Monster Maze. That farrow game, Against the Elements, is jaw-dropping. Certainly as good as many offerings on much stronger machines, like the Vic 20 or C64

[@sebafa0911]

so you're 62 now

[@grainyday]

fucking legend - I was 7 year old boy - typing meticulously games from my book . i didnt know shit about computers and no english - but had ton of excitement and fun . great days

[@rog2224]

J K Software did a rather steely 16k game - 3d Space Invaders. I remember playing it quite a lot in 1982, along with Trader.

[@Fuuntag]

Always loving your upbeat tone and delivery!

[@b0rg1010]

Yep, I remember that when I was 8 year's old. Every time you knocked the table it would reset. Lol It's what got me excited for micro computers of which I now do as a career.

[@arnierc4]

Lol I thought that was just mine due to age. I actually have the timex rebranded model sold here in the us, but the same machine. Gotta be careful punching in basic programs

[@Hologhoul]

Wow! I owned a ZX81 but had no idea it was possible to programme some of these games, really impressive. I was always fascinated by Scramble (or whatever name they gave it), just seeing a port like that on the '81 was great.

[@Blitterbug]

Yah, machine code programming was it's little-known secret. I was inducted into its dark arts by a pal at technical college and never looked back - like you it blew my mind that actual arcade games were possible, until I understood how it was done. The penny dropped and I was suddenly in love with programming like never before.

[@Hologhoul]

@@Blitterbug I would have loved to have done that, but although I programmed a few games in BASIC, I think that was likely my level!

[@Blitterbug]

@@Hologhoul Mine too til my friend showed me the manual had all the z-80 instructions, and how to use POKE to stuff a machine code program into RAM from a bunch of DATA statements in a FOR-NEXT loop. Was all black magic at first!

[@Hologhoul]

@@Blitterbug It must have been fascinating and really satisfying when something worked! I'm intrigued by the Atari VCS as well. how they programmed that, sounded unique and complicated!

[@donaldklopper]

Solid job on this video. This was great fun to watch.

[@Peter_Scheen]

I once build (in Basic) a game called "Star eater" on the Z81. I put a V as the ship in the first line, placed objects on the last line and used the Scroll command to scroll it up. Used Peek command to look in video memory if I hit something. It worked. My first Basic program that worked. Noteworthy is that it was Spaghetti programming.

[@ericbernard8864]

My first love as a computer! I begun programming on one like this,with ram module and printer! Such memories...

[@Tore_Lund]

Oh, that single needle thermal printer!! Could print a receipt sized page in 10 minutes.

[@dogwalker666]

@@Tore_Lund the smell of the thermal paper after printing a long listing.

[@Tore_Lund]

@@dogwalker666 That too, and yes, it was the most convenient way to save your programs for later retyping.

[@timwilcox5158]

Excellent video. i have a lot of love the the old "81".

[@jonsmith1271]

Thank you for the memory recall :). Ocean trader captured many of my hours as a 11/12yr old. (But nothing of a technical game, by comparison )

[@_misnoma_]

A nice trip down Lack-of-Memory Lane! Later, the ZX Spectrum's capabilities and commercial games far outshone home-grown efforts. But in the early days of the ZX81, the playing field was level. Our own efforts in BASIC, or input laboriously from magazines, could compare. I'd challenge my younger sibling to a new home-made V-dodging-asterisks challenge without shame, and fun was had.

[@robinbrowne5419]

Back in the 80s I used to play Monster Maze on my ZX81 with my 2 kids watching. They would hide their eyes every time the monster showed up :-)

[@tetraquark2402]

Had great fun coding in a bit of assembly using the memory block instructions to make falling text.

[@smd1uk]

I seem to remember that the advertising blurb in Personal Computer World implied that you could run a power station with it!

[@BertGrink]

Ah yes, I remember that ad too! 😁

[@carstenweiland7896]

Since there are new commentary's on a 3 year old video, I have to confess that as a child I always wanted the ZX81, when I finally got a Computer I managed to get my hands on a VIC 20. Since then the urge to get a ZX81 never left my mind and I still resist to buy one. Maybe build one from scratch would be fun.

[@ShroudedHand]

awesome video. although, can emulation ever provide the true experience without the screen flickering and the whole thing crashing if you jog it too hard

[@withlessAsbestos]

Wow I’ve never seen you in the comments.

[@ShroudedHand]

@@withlessAsbestos sup!

[@withlessAsbestos]

@@ShroudedHand not much just trying to make videos for Christmas

[@ksportz66]

Only crashed if you had wobbly 16k RAM pack.

[@TheT0nedude]

@@ksportz66 just use some blue tac to keep it stable...

[@JohnnyWednesday]

I love your content man! you really know what you're talking about and you've clearly got a keen eye for a gem! - I'm a programmer to the core, love the machines we grew up with and couldn't fault your views or terminology even if I wanted to. Which I don't - keep up the amazing work!!

[@Sharopolis]

Thanks very much, more to come!

[@BigCar2]

Great work! There are a lot of games I'd never seen. Amazing what people can do with the old beast.

[@Sharopolis]

Thank you!

[@rachel.mcgowan]

That grinning maze monster is genuinely disturbing.. it's the mouth

[@Sharopolis]

It sure is!

[@Michael-im5mq]

@@Sharopolis Proof that even such a basic microcomputer can still make some immersive games

I loved the flight simulator on the ZX-81 (TK-82C in Brasil). Played (a lot) the T-Rex labyrinth, too. That's a time travel video!!! Thanks a lot for it!

[@BollingHolt]

Cool. This was my first computer (as a Timex Sinclair). I was only two years old at the time, but as I grew, I do have a few memories of it. It's fair to say that I really cut my teeth on my CoCo2 I got for my 5th birthday. I didn't know that tiny machine was capable of such!

[@ThoughtandMemory]

I played miner in the 80s. Met the guy who programmed it in the 90s. In Swindon of all places. Very smart guy.

[@twotone3471]

3D Monster maze was one of my favorite Atari 2600 games (1983's Tunnel Runner), didn't know it was a port from another console though.

[@johankoelman2996]

May 2020: 74 1K hires games from Dr Beep. Latest project 10 1K lowres games and a new version of the ZX81-emulator for the 48K ZX Spectrum.

[@Sharopolis]

Is this the man himself? Thanks for stopping by! Looking forward to seeing more from you in the future.

[@johankoelman2996]

@@Sharopolis, yep it is me. As said soon 10 games on tape at Cronosoft. I have an idea for a new 1K game. Thinking if it should be 1K hires or 1K lowres with Chroma-characters.

[@philjohn2649]

“Games of a silent era” that’s a great description.

[@SiskinOnUTube]

Crazy Kong was my fave zx81 game. Other than that I spent ages typing in basic software from a book I had got with the machine. Great fun.

[@mwienzek]

Fantastic - thank you for sharing!

[@CooChewGames]

Really enjoyed the video :-) Big fan of the ZX81 and have very fond memories of 3d Monster Maze, 1K Chess and Mazogs; which I reckon pushed the hardware with the procedural generation of mazes and excellent (large) animation. I also covered those games in The History of Computer Games (Abridged) which was made for a competition a few years ago (when I had hair). I missed the high resolution stuff though as I had, as you mentioned in your video, gone onto great things with the Speccy :-)

[@johankoelman2996]

Last week I scanned MAZOGS for delayroutines and I think the program is crosscompiled and therefore has a lot of overhead. Mazegeneration is not that hard to do on a ZX81.

[@Cornz38]

Remember opening my ZX81 on xmas day, the first program i ever typed in was the "plough" program from the manual. BTW, PRINT USR1+USR1 will cause a 1k zx81 to produce audio through the tv. I kid you not.

[@michaeljonas3165]

I recently found a 1999 BASIC-only implementation of Minesweeper and after I optimized the BASIC a bit (reorganized code, give % feedback on setup, and simplified the cursor update by using a string array of graphics vs 6 lines of if/then's) to speed things up and it actually is very playable speed-wise. It takes a bit of time to clear out half the screen if you are so lucky to select and open spot but if you are busy doing stuff then you can play it sort of in the background and get a few good games in during the span of an hour. Someone mcoder'ed the original version but the BASIC-only was slower. Maybe we need a list of top playable BASIC only ZX81 games :-/

[@johankoelman2996]

kzbin.info/www/bejne/paaXpWd8gcuhotU

[@thefurthestmanfromhome1148]

THE machine that got me into gaming. 3D Monster Maze just blew me away at the time. But hat tipped in direction of Mazogs 49er 3D Defender

[@paddycoleman1472]

First time I have ever heard the ZX81 described as a “Platform”! 😀 My first computer was a ZX81.

[@Sharopolis]

More of a drinks coaster than a platform I suppose!

[@GreenAppelPie]

There is no way in hell I'd call that a platform.

[@scality4309]

Was my first also. First console was videopac.

[@herrbonk3635]

To me, a platform is where the trains leave.

[@SANS_THE_SKELETON666]

I remember that when my Grandparents had a ZX81, I used to play 3D Monster Maze ALL the time.

[@looneyburgmusic]

3D Monster Maze was definitely out in '81... that was the year I broke my arm into a half dozen pieces and was hospitalized, and when I came home there was a brand new ZX81 waiting in my room with 3DMM and some other racing game as a present...

[@mmaldonadojr]

The ZX81 was a miracle of its time, even without any program loaded it already pushed the limits of its CPU (a 3.25MHz Z80) since it had no video controller and the CPU had to do the video signal synthesis. I learned to write sofitware in this machine, BASIC at first, and Z80 machine language afterwards. Good old hacking times!

[@-Steven-]

It's amazing what real coders can do in just 1k of memory, compare that to today's games it seems impossible. BTW just for reference denuvo drm adds about 300 megs to the size of an average game (it's the only thing i could think of to compare lol).

[@danmanx2]

Very true. kkrieger was I think 64kb in a FPS! FYI, Denuvo was defeated successfully by the Doom community. Rip and Tear, brother!

[@Mostlyharmless1985]

Not much, actually. You sure ain’t fitting AES in 1k.

[@big0bad0brad]

AES? The encryption? 1K would be tight but doable. I've fit it in 4K (UPX compressed) along with a minimal 8088 BIOS (custom for Sanyo MBC 55x series). You would probably have to only hold one substitution table in RAM at a time and might have to generate subkeys on demand. My implementation needs 1,129 bytes but if I dropped one of the substitution tables it would work. But to do anything useful at the same time you probably have to go further.

[@bukster1]

I've coded a jewel drop game and a Sudoku solver on the 1K ZX81

[@michaelgallimore3707]

My very first home computer! Great memories. I was just a kid 👍🏻😁🤘🏻🤘🏻🤘🏻🤘🏻

[@burbercat3558]

There's a ZX81 port of Manic Miner of the first 8 or 9 levels. played it some years ago, proper good it is.

[@DoItMyselfGarage]

I hand programmed in hammurabi into my ZX81. Had to store it on tape. Was a great way to learn programming.

[@richardoakley8800]

I had a zx spectrum 48k.. simple and cheap.. and with so little memory compaird to an IBM you learned to write very efficient programs.

[@philoffhistree6700]

this is uncanny that you did a zx81 right now, over the last week i had a sudden urge to buy several zx81s off ebay, i never owned one the spectrum was my machine in 83 but i already collected about 20 of those, so anyway I now know hwat games to start on as i havent a clue when it comes to the zx81, i also got over the last 2 weeks a few Oric 1s an Oric Atmos an Acorn A3000 and 5 zx80s, no idea what games im going to get for them all, oh yeah i also got an Atari 2600 an Atari 800XL an Atari st 520 a stfm 520 and a stfm 1040, so you better come up with some more videos for that lot as i need some good game ideas now.

[@philoffhistree6700]

Oh and now today i just picked up two vic 20s yet another zx spectrum and a ti99 colour computer ? as they were in a job lot on ebay and got my eye on a few more things in the next few days, so come on get making them videos Sharopolis

[@philoffhistree6700]

god i need to stop i just got 3 commodore +4s as they were going for a song, all in mint condition but only one is known to work

[@bernardfender5147]

Arcadia on the Vic20 was damn near impossible!

[@philoffhistree6700]

@@bernardfender5147 ooo i will get hold of that then love hard games

[@dcocz3908]

I can tell you, next up is the breakdown and then divorce

[@ancipital]

just got suggested this video - that is cool! Thanks

[@Sharopolis]

Glad you liked it!

[@Bethos1247-Arne]

THAT THING CAN DO GRAPHICS!!! OMG, I never knew. Even though restricted by lines of pre-defined characters, the graphics which were achieved are insane for this level of tech. I though ZX80/81 had really only text and blocky "graphics" using full 8x8 chars.

[@heyhonpuds]

Cool vid, although I was expecting to see Mazogs. It’s where Don Priestley cut his teeth before making even larger sprites for the Spectrum.

[@Sharopolis]

There's a great colourised version of Mazogs that I might put in another video if there is any interest.

[@heyhonpuds]

I’d watch it.

[@ZXFruitcake]

@@Sharopolis And now also a native colour version of 3D Monster Maze that runs using the Chroma interface on the ZX81!

[@richretrotech9426]

My first computer was the zx81. I'm just discovering now emulation and playing games I never did as a kid!

[@RetroSegaDev]

Another great video 😁

[@Sharopolis]

Thanks!

[@temporarilyoffline]

Great Video, now I have to buy that color kit for my ZX81

[@Sharopolis]

Thanks! I just checked out your channel, you should get one and do a review!

[@temporarilyoffline]

@@Sharopolis next on the list after I build the #sixtyclone!

[@ksportz66]

I did.. was a sheet of green platic film I stuck on my TV. I spent hours getting all the air bubbles out.

[@drxym]

Probably the most technically amazing game ever written for the ZX81 was Chess - someone coded an entire version of Chess into 1Kb of RAM. There are articles about it even today geeking out about how it was done. As for 3D monster maze I remember seeing it in the computer lab at school and being amazed. However when I saw other ZX81 games being played I was less impressed. Even the the graphical games that appeared were impressive as a technical achievement but compared to the ZX Spectrum games they weren't at all great.

[@wisteela]

Excellent video. It did actually have graphics, but from what I can remember it was basically pixels a quarter of character size.

[@johankoelman2996]

Correct, you can see a lot of them in 3D Monster Maze.

[@gwishart]

Officially, the ZX81 only supported character graphics. However, the character set included block graphics characters that could be used to simulate a 64×48 pixel bit-mapped screen.

[@cst1229]

I'd like to see the non-pusedo true high res explained.

[@EamonBJWyse]

I remember seeing the Sofware Farm games and freaking out back then, buying them by mail order and was so excited. Pretty sure I bought one of theirs and it never got released, but can't remember it's name. 49ers and Rocket Man? I had.

[@DeathRaven.]

Imagine the creators of the 1k Chess reacting to how massive games are now

[@G7ennx]

Mazogs was the game I put most time into playing. I’m not sure how much it pushed the system, I know it was part (mostly?) basic but there must have been pretty efficient machine code to update the whole screen as quickly as it did. Also arguably some of the best animation on the zx81

[@lorifairhead8124]

This video seems to focus on high resolution graphics games but you can do so much with the simple native graphics of the ZX81.

[@Larry]

Were you tempted to put that port of Dragon's Lair on this list? But there's also the Chris Sievey (Frank Sidebottom) music video, Camoflague that ran on a ZX81 that's quite impressive too. though obvioully not a game :D

[@Sharopolis]

I couldn't find a copy of the Chris Sievey one, it pops up on ebay from time to time, but there's no image of it online that I could find. I was going to put Dragons Lair in, but A) I couldn't find a copy at the time and B) It does seem like it's cheating a bit using the extra hardware it requires. If I do another ZX81 vid it'll be in there though!

[@ecernosoft3096]

0:27: "And so first off.." Me: It's 3D monster maze! 0:36: "but 1K chess" Me:

[@interghost]

Impressive for the system!

[@PrivateSi]

Seems to run an early version of Crysis fast enough.

[@GeneralThargor]

I remember typing games into it from a magazine feature was called 1k corral in, it was in every month.

[@bobpert4030]

No mention of the infamous "rampack wobble". Could make a grown man cry.

[@10tonhamster]

REALLY surprised there was no City Patrol. By Don Priestley, who went on to make Trapdoor, Popeye etc on the Spectrum.

[@Keeping_IT_Simple]

A very great trip down memory lane for those of us old enough to remember the era. Any change of the link to the Brazilian pitfall style game please?

[@Sharopolis]

Argh! Good point! I forgot that, thanks for pointing that out. It's in the description now.

[@iwanttocomplain]

There was Flight Simulator. A fully 3d flight sim made of some dots. Riveting stuff.

[@gwishart]

All computer flight sim graphics are made of dots, just some are bigger than others.

[@greenaum]

The ZX81 didn't have a slower CPU, it was exactly the same speed (and handily meant Uncle Clive didn't have to shell out for a second clock crystal, hooray!). It's also not unlikely it took as much time to puke out a pseudo-hires screen as a traditional text one. In either case, the CPU is occupied during the in-use scanlines. It's just punting out rearranged bytes rather than the traditional ROM arrangement. I confess I haven't read any pseudo-hi-res code but I'd imagine all the vertical byte-slicing is done offscreen, using the "SLOW" period of the CPU's time, during the borders, etc. I would also imagine (it's how I'd do it) that a character-sliced version of the screen is stored in RAM, and the character-converting is done as part of the dot-plotting routine. You'd read the byte of screen you wanted to draw to, then alter it with the new pixel you were adding. Then from there, take the byte thus produced, and look up in a table of 256, one for each possible arrangement of the 8 bits. That table would match the 8 bits you wanted to put into screen RAM, with the closest character available that matched that. That would be what you'd then plop into RAM for that location. How you'd work out which vertical slice of the characters you'd use, I don't know. I imagine you'd look through the Speccy character set and choose 1 slice that had the most variation, and stick with that one for every line after. Anyway... dot-plotting on the Spectrum involved reading bytes, ORing and ANDing them, then writing them back. So the ZX81 method not that much slower, and then the main screen-draw routine no slower than the ZX81's default. So all in all, pseudo-hi-res not really slower than ordinary ZX81 operation.

[@chrispenn715]

i remember trying to get the 1k chess to work on my ZX81 - never did succeed and I couldn't afford the memory expansion for better programmes. I later traded up to a Dragon 32 - oh the luxury. My hobby also got me my first management job - implementing the first computerised sales system in a large company (not based on ZX!) Every other manager was scared witless of computers - so I just got stuck in. :-)

[@damianvila]

This video will benefit greatly from chapter being added to it... Great video, though.

[@bukster1]

I was hoping to see some of my programs here such as ZX81 Jetpac or Tractor Beam which is a Galaga clone. Perhaps if there is a second video like this I'll get a mention.

[@shadowside8433]

Watching this sort of thing reminds me how lucky I was to have my Vic-20!

[@UnboxRacing]

A calculator pushes the limits of the ZX81. Some of these programs were astonishing re-engineers of the entire system.

[@TrockeyTrockey]

'AGAINST THE ELEMENTS' is amazing :) It is funny because it is 2016 production. Coders from 80. was not so talented, as today :)

[@andrewnorris5415]

Great vid! ANd loved all the humour in there! 10's of pounds lol.

[@Sharopolis]

Thank you 😁