ZX81 still awesome after 40 years!

[@DanFre40]

My first computer was a ZX81 and this brought back lots of memories.... I remember standing the ZX81 on a book and having the ram pack lean off the back of it, so that it would maintain a good connection. I'm a database guy now so the ZX81 sparked a lifelong interest in computing, but I'm always in awe of people who can understand how things work at the hardware level and make tweaks and upgrades to computers like this!

[@SteveLawrance]

Awesome. My ZX81 set me on a path to a career in IT. What I learned most was to be efficient when coding, something I think has been lost, these days, you only need to throw a few more gig of ram or GHz of processing power to overcome performance issues instead of looking at the code and refining it... Showing my age now... Excellent vid, keep up the great work...

[@davidkempton2894]

I had one. Such a thrill to own a computer!

[@robingrosset6941]

totally!

[@paddycoleman1472]

The ZX81 was my first computer too. Yes the specs were poor but it was a computer and nothing else came close at the time in terms of price. Sinclair and his low cost computers did so much to make the UK a technology powerhouse in the 1980s and beyond.

[@barthonhoff5547]

Not only in the UK. Also in other countries, like the Netherlands. Me and many of my friends of that time made their carrier in IT later on. BTW they are still my friends.

[@raptorman0]

I bought mine with my paper round money. I wasn’t considered smart enough to do computing at school. This makes me so nostalgic👍

[@The65c02]

Same here, not considered smart enough as I was only targeted a C in maths. I left school and became a computer programmer, never looked back.

[@robm8809]

Same here too. I also went on to have a career in IT, including programming.

[@StarsManny]

How much did you get paid for your paper round? How many papers per round? I want to work out how many papers you had to deliver to buy your zx81.

[@carlo.studentsworld2904]

That was emotional! Man, you basically described my life as an Italian 8th grader while learning the basics of computer programming on my brand new ZX81 in 1981. Apparently we share the same amazing moments in our lives.

[@QLvsJAGUAR]

Happy to see other KZbinrs celebrating the anniversary! I had such a good party, all alone on my own (not only) due to Corona, celebrating the ZX81 to the max! I’m so happy to share my happiness with you folks! #ZX81IS40 It would be great if we all use this hash tag in the video title. Happy Birthday Zeddy!

My first contact with a PC was with the brazillian version of the ZX81 (TK-82C), in 1984, when I was with 11 years old. My father bought it to use, as an engineer, for his work (charts, graphs, programming to have some prognosis of the plant, etcetera), but he allowed me and my sister to use it, as an introduction for programming and personal computers. In the begginning I used it for games (writing programs from PC magazines or dedicated cassettes), and writing basic (literally) programs, like printing something on the screen. This made a lot of (positive) difference when I started studying programming at school and later at the university (Industrial Automation).

[@scotthannan8669]

Timex Sinclair 1000 was my first computer. Such a clunky thing but it was definitely a fair introduction to personal computing. Had the printer and tape and ram expansion. Had a ZX80 also but it was sooooo limited.

[@kensmith5694]

The ZX81 PROM would go in a ZX80 and make it work as a ZX81.

[@JimforbesRitte]

My first machine too! Got one with the 16k RAM pack and alphacom printer for my birthday in ‘83...

[@zapod20]

This was also my 1st computer, leading to an IT related career which I still do. My school was lucky insofar as we had access to Apple IIs, Acorn Atoms and a BBC Micro, a Commodore PET and a Cromemco, so my introduction to computers was quite varied for the time.

[@richretrotech9426]

ZX81 was also the first computer I owned. Awesome introduction to computers. I had the memopak memory expansion and hi-res pack along with the printer too!

[@ian_b]

I had the hi-res pack but I remember all the drawing routines on it were unusably, painfully slow. I sometimes wonder looking back whether that was a fault on my unit or they were all like that.

[@richretrotech9426]

@@ian_b that we’re all like that!

[@ian_b]

@@richretrotech9426 Thanks, I thought that was probably true but it always niggled at me :) I remember there was a "shoot" routine that would draw a vertical line up until it encountered another pixel and the manual said it was useful for games. Yeah, like if you want a frame rate of 2 frames per minute haha.

[@CptDangerous]

Hi Robin, I like your term "bodge wires"! When I was designing PCBs for bespoke data acquisition projects I'd nearly always miss the odd track or two and have to add "concession links" but, yep, they were bodge wires. :-)

[@wooferhound7571]

Also My first Computer, Learned BASIC and Assembly Language on it. Wish I had discovered the Hi-Res mode when I was messing with them.

[@nThanksForAllTheFish]

Thank you for this video - like many other commenters here, the ZX81 was also my first computer and I still have a working one... and some 62256 RAM chips :)

[@mrdebug6581]

ZX81 ... my source & forge of *EFFECTIVE* programming, until today ❤

[@jazzad]

My first too. Learning what to do out of it was incredible. My biggest achievement was coding a playable Tetris on is. It wasn't rubish. It was making things work with the least possible ressources.

[@TheSulross]

my first computer was a Commodore 64, which was gifted to me by my oldest brother (17 years older than me), so yeah, even the c64, which cost considerably less than an Apple II, was still rather more expensive than those Sinclair Z80 computers. My system had a composite monitor and floppy drive - less than a thousand dollars, but more than $500. Sinclair computers could be used with TV and cassette - where a family would already have a TV, and cassette players a lot less than Commodore floppy drives. It was a valuable first entry to computing for the masses.

[@dab42bridges80]

The first PC I owned, taught myself Assembler and Machine Code on it as well as BASIC.

[@kensmith5694]

I had the slightly odd Z80 assembler/editor that ran on the ZX80. It was a wonder to behold.

[@TimGilberts]

Lovely to see these videos starting to appear ahead of its 40th Birthday Friday. Like you it started my interest in Computers as it was all I could afford saving from my part time job. I recently restored my very original one but, due to a faulty regulator the original early ULA died. I now have a modern replacement ULA in it which saves fiddling with the CCB mod needed for early ULA's I had fitted previously.

[@robingrosset6941]

cool!

[@davepodolske5646]

I had the Timex 1000 version. SO cool to write programs on the keyboard at home, instead of writing them down with pencil and paper and waiting to use the Commodore PET at school the next day. That space invaders game had to be assembly, there's no way the BASIC was fast enough. Great video, brought back a lot of memories.

[@MeppyMan]

Thanks for this video. Love all the ZX81 KZbin content lately. It was also my first computer and I remember connecting to a composite amber monitor without any extra electronics when I was a kid.

[@chancanasta]

Great video, thanks for showing my HiRes Invaders game - love what you're doing

[@miikasuominen3845]

It seems, that people outside Europe just really don't get it. The 8-bit guy also totally trashed and laughed at it. True, it IS a shitty computer, compared to something like VIC-20 etc. But it made computing available to ALL here in Europe (specially UK) and teached people to program and so on. I have one, needs a little work still though ;)

[@ian_b]

Totally agree.

[@carlo.studentsworld2904]

Vic 20 (and C64) created a generation of videogamers. ZX81 created a generation of developers which is far better.

[@DeLorean4]

It's what got my father into computing back in the day as well here in Canada. The Timex Sinclair 1000 was fairly popular here, but everything afterwards was a flop and Amstrad didn't seem interested in keeping the Timex partnership going. It's a real shame because the T/S1500 was a perfected ZX81 and the T/S2068 was an enhanced 48k Spectrum. Timex did a fantastic job addressing some of the functional shortcomings of the Sinclair products but was seriously lacking in the styling department. I learned to program on the 2068 in the 2000s because I didn't have a modern Windows computer of my own. It was a great experience, and the keyboard stimulated my curiousity: "How do I make the computer DRAW? How do I make the computer BEEP?" etc. Good luck repairing your ZX81. I got my T/S1000 working yesterday for the first time since 1992. It's been a blast.

[@olaf_dreyer]

I *loved* this! I had the basic 1k version and it was the first computer that I owned (my math teacher had a small Sharp BASIC handheld that I could borrow and play with). Of course I was looking at the fancy Apple II but that was way out of my prize range. I was just thinking about that machine and comparing it to a Raspberry Pico with 256K that you can get for $4. Thanks for the video!

[@robingrosset6941]

Totally, this is also why I buy into what the Raspberry Pi Foundation is doing, price and good documentation for folks makes the difference between machines being accessible or not for people.

[@mymusic7262]

OMG I cant beleive that space invader graphics and speed could ever be possible. I thought mazogs was mind blowing.

[@j0hnf_uk]

Of course it's a, 'rubbish', computer, in retrospect of what was to come, even a few years after its release, but for many it was the first home computer most people could afford and was a perfect introduction into the world of programming. I spent my entire summer holiday off school in 1981 learning how to use one and, by the time I went back to school, was proficient in BASIC. Amazing how I would spent hours and hours on the thing, writing all kind of programs, mostly games, to try and emulate some of the arcade games that were around at the time. Of course, they were never anywhere as good due to the sheer limitations of the machine, but at least it got the creative juices flowing. I graduated onto a ViC-20 and then a C64 as the years went by, but I'll always remember using this machine on a little 12" portable black & white, alone in my bedroom with just the light from the TV due to being so engrossed in using it that I never noticed it getting dark!

[@desiv1170]

You can also repurpose that channel switch to a 50/60 hz toggle. Not totally required, but at least it makes the switch useful again. :-) Great vid.

[@horusfalcon]

I still have fond memories of my ZX-81 and the several TS1000s I had (most purchased at clearance for about $10 US). I no longer have any of them - time has taken its toll. The composite mod was a bit that needs to make the rounds! That was dead simple, and very effective. The 16k internal has me wondering (and searching for a schematic): how hard would it be to get to 64k? Thanks for a fascinating look into the past.

[@danielegasparini4391]

Very interesting video about ZX 81.

[@stephenwong9723]

So interesting to see you use wire-wrap tools on an IC pins!

[@dreamyrhodes]

Z80/81 was kinda like the old granny of the modern Raspberry Pi (especially the first versions): A cheap computer that lowers the entry level. It's not fast, it has its limits but it's affordable and relatively easy to use with it's BASIC (today we have Python, which is much more powerful but also a good entry-level programming language).

[@byteforever7829]

Love these, tempted to buy another

[@gazzaka]

Awesome, and that's a wrap !

[@sbmicro1896]

ZX81 for ever ! 👍

[@klave8511]

Real ZX81 programmers use N as the loop counter! The 7805 should really be changed for a switching regulator, it dissipates quite a lot of heat because the power supply voltages is so high, not as much as the ULA but it does run nice and hot. I would have tried to makes the wiring changes for the RAM on the board rather than directly to the ic, is that possible?

[@markaffleck4622]

Hi Robin I have watched several other videos on doing the RAM upgrade and they al show that pin 26 should also be bent out and connected to diode d25 as well. They also show that the link 2 should be closed. What is your take on this? Regards Mark Affleck

[@JCMayPE]

I'm always marvelling at the newer ZX81 and TS1000 boards. Mine (American, NTSC ZX81) was assembled Christmas Day, 1981. All the resistors were installed vertically... But instead of just bending one of the leads to fit, the assembler cut off one of the leads, soldered the cut lead into the board and then soldered the cut ends back together. So ugly

[@robingrosset6941]

Wow thats very unusual.

[@tenminutetokyo2643]

Also replace the 7805 power regulator with a TRS-1 2450 and you can dump the heat sink. Runs cool to the touch and is 96% efficient.

[@SusanAmberBruce]

Nice video thanks

[@kensmith5694]

I had a ZX80 that could run as a ZX80 or ZX81. I had the image of the two PROMs in two parts of a much bigger EEPROM. A switch worked the upper address line.

[@powderslinger5968]

No way you had slow mode without the 81's Ferranti.

[@kensmith5694]

@@powderslinger5968 I had the slow mode. Details are a bit fuzzy in my memory but the slow mode logic was not some strange thing. The standard logic chips could do it. All the slow mode did was run the code briefly in the vertical retrace time.

[@y2ksw1]

I got 2 and turned me totally on.

[@SiskinOnUTube]

I keep thinking about tackling the broken zx spectrum I have. Probably a big headache.

[@Zanaz728]

I wasn't born yet..( the 8 bit time) but I'm interested to play around with it. Where can I get one, thanks.

[@hagen-p]

If you have not seen it yet, please check out the ZX-Wespi-V.

[@yoonsikp]

don't know what you expected after sending it to Dave...

[@Togidubnus]

Anyone who poo-poos the ZX81 clearly had far too much disposable income. For me, it was a way into computing at (almost) pocket money prices. I used all the money from my paper round, plus Christmas money, to buy mine in 1982. I still have it and as far as I know it's fully functional. I later got a RAM pack, but it was truly terrifying.Despite the lack of sound output or cooling fan, it was curiously noisy: you could actually hear it calculating stuff.

[@tlmooney]

Hello. Have you any interest in a Pico edition of a zx system??

[@DnBclassictunes]

how do you know all this stuff? cool

[@ksportz66]

How do you load HI RES space invaders into the ZX81?

[@robingrosset6941]

You need the tape file (.tap) and a tape file player. There is an application that uses Java for Windows or Mac or Linux I think there is a phone app too. Check here www.zx81stuff.org.uk/zx81/tapeutils/overview.html What I found was playing the tape file on my laptop and recording to normal magnetic tape worked best as I could get the volume just right more easily when loading to the zx81

[@tlmooney]

Hello have you any interest in making a Pico version of a ZX

[@chrisrobson8540]

pity that wasnt how it came as standard......could have been so much more

[@bborkzilla]

It was rubbish computer in the same fashion a KIM-1 was. For $100 US it was a bargain and a cheap way to figure out if you were really interested in that sort of stuff.

[@martindejong3974]

I also had a KIM-1, my first full working computer, where I learned 6502 Assembly language on, the ZX-81 came a few years later and was the first computer I owned that ran BASIC, Later I built a LNW-80 computer, a copy of the TRS-80 model 1, but with Highres colour graphics.

[@rlk54]

I used to have a 64K Ram Pack

[@kensmith5694]

That was back when 64K was a lot of RAM.

[@dolst]

16K internal RAM upgrade? I mean, I guess if you *really* don't want to just stick that big old 16K brick on the back...... 🙄 Surf Wisely.