ZX81 Classic PC

ZX81 overview and demo! The Sinclair ZX81 (known in the US as the Timex Sinclair 1000) was my first computer, and here I look back to its revolutionary hardware and programming. I also run some ZX81 games that I published in the magazine “Sinclair Programs” in 1982.
The ZX81 emulator shown in this video can be found on Simon Holdsworth’s fantastic website at: www.zx81stuff.org.uk
The listings for the two programs I demonstrate can be found on this page: explainingcomputers.com/zx81_v...
If you like this video, you may also like my report on early PCs at the National Museum of Computing: • Early PCs at the Natio...
More videos on computing and related topics can be found at: / explainingcomputers
You may also like my ExplainingTheFuture channel at: / explainingthefuture

[@3dduff]

the ZX81 was also my first computer. My father would ask me "How are you failing MATH, but programming games?" Thanks for the trip down memory lane, and keep up the great work!

[@DarronBirgenheier]

In our cabin in Northern Vermont in the early 1980s, after I and my cousin had spent a LOT of time programming something fun on my TS1000, my father turned off a light switch that controlled the AC outlet that the computer was plugged into. Poof! Bye, bye, meager programming efforts!

[@rickappling5470]

I has a similar problem. It was back in the sixties. Only the question was how I was failing basic arithmetic. But had taught myself the slide rule. And a little algebra and trig. There was now program for gifted students. And I don't even know if ADHD was even known back then.

[@ian_b]

"Because the school maths isn't in base 2!"

[@lordpitnolen2196]

The ZX81 was made in Dundee, Scotland, more usually assembling clocks and watches. The staff were encouraged to buy one and could do so at a very good discount to the retail price (£99 I think). Staff take up was high as staff were selling them on to other locals, like myself, for less than £99 but often for a bit more than they paid. It was my first adventure into computing and I enjoyed the hobby. I bought an external keyboard kit, having to solder every key separately. I also fitted a memory extension unit but these products were very unreliable. If the unit moved slightly the computer crashed. I fitted all the bits onto a piece of plywood, adding some extra support for the external memory unit. I enjoyed many hours on my ZX81, but not to typing programs from magazines that always resulted in typos. Very nostalgic to read about the ZX81, thank you.

[@pintokitkat]

It was my first one too. Brilliant! Although the biggest headache was not the lack of ram, colour or sound, but the need to continually answer the question from bemused family and friends, 'Ok, so it's a computer. But what is it for? '

[@richardhince9764]

Crikey, do I remember that question! I used to tell them that it couldn't do much (although there was the famous quote from someone that it was capable of running a nuclear power station - do you remember that?!) but that one day computers in the home would be commonplace, and that we would be able to do things that we couldn't imagine at the time. Now look where we are!

[@stevemichels5608]

Yes... my Dad ridiculed for me for my refusal to "stop wasting my time" on those "worthless" computers! LOL!!! He lived long enough to own one himself, and of course, I helped him learn how to use it (and set it up for him). I experimented with digital circuitry when I was only 11 and had only J-K flip-flops and Nixie tubes to work with, and drew block diagrams of what computers became a few years later. All water under the bridge now! Yes, the "questions"... Maybe not as bad as what Leonardo Davinci had to put up with, but daunting, nonetheless. Steve

[@billfusionenterprise]

sending spam?

[@oleimann]

We had ZX81 in school for voluntary computer ‘class’. But my first self-bought computer was a Commodore VIC20 (VC20, the german edition) More RAM less Mhz😁

[@billfusionenterprise]

but ran better by the ways, the way back machine has all the old magazines for the commodores

[@MeesterVegas]

My first computer too! I actually got it in kit form, and soldered all the components together. I still remember typing in programs from Byte magazine for hours, only to see them disappear late in the morning hours because I didn't have a cassette storage unit yet. This really brings back memories. Thanks for the video!

[@gerrytemple5044]

For me the VIC-20 was what the ZX-81 was for you. A fantastic machine that taught me programming and made me creative. Still love Basic today. Thank you for this beautiful retrospective!

[@ExplainingComputers]

We share an era I think! :) Great times those.

[@MarsMountain]

I can't thank you enough for bringing these memories back! The ZX81 was my first computer as well, and I remember those books and magazines. Sadly mine had a problem saving programs on cassette, so I stuck to the shorter programs. I also remember the feeling entering a longer program, and then accidentally touching the very sensitive RAM pack. It always led to a hard reset. Finally the keyboard gave up so I sold the mainboard to a friend who needed it for repairs. To sum it up I had a couple of very joyful and educational years with my ZX81.

[@IanHodgetts]

I recall one magazine listing in machine code that took about half an hour to enter. You ran it (obviously without saving it to tape first) and it displayed "APRIL FOOL!" and then restarted the machine! :-D

[@RubenCarlosCalderonValladares]

I had the privilege to use both the Sinclair ZX81 and the Timex 1000. My father and his brothers sold them in the early 80's in Peru,my home country. I was a very lucky 7 year old kid: I got the ZX81 for Christmas! It was a defining moment for me, I learned about computers and programming with these amazing machines!! 😀

[@simonkerridge]

Now I feel old! My first computer was the Sinclair ZX80, and I followed that up with the ZX81 and then Spectrum (and even the Sinclair QL eventually). This video makes me quite nostalgic for those old days.

[@kensmith5694]

I still have a ZX80. Maybe I will fire it up to see that it still works

[@Robert-Dusek]

They were very popular in Eastern Europe. I did get my ZX81 in 1987 as present from my US friend, while studying cybernetics at University in Pilsen, Czechoslovakia. It liberated me from my dependence of signing up for time on PDP computer at the university and a typewriter to write my papers. Now I was able to work at home and print on a converted teletype as printer (the whole house was shaking). We also developed a battery backed CMOS RAM to instantly load all software after crash, to avoid loading everything from tape when crashed. It was like a miracle at the time.

[@todddunn945]

That brought back memories. In 1982 I was writing my Ph.D. thesis and used a Timex Sinclair 1,000 to analyze infrared spectra using a fast fourier transform using gaussian curves. It was a real challenge to program that with the available memory and VERY tedious to enter the IR spectra to be analyzed. However, it was a huge step up from my TI59 calculator.

[@TheWildsourdough]

Timex Sinclair ZX 81 was my first. Drove 100 miles in the summer of 1982 to get it. Read the mags and taught myself BASIC- By fall, got a job as a programmer of IBM system 23s and 5120s.- Bigger, but not really better. Fond memories- Thank You !

[@mickkeeble3079]

1981. I was a Systems Programmer working on IBM mainframes and had an electronics hobby (which I still have!). I used to build ZX81 kits for a number of people. The only personal computers we had at work were 2 Superbrains (running CP/M and enormously expensive) in the Finance dept. Anyway a lot of computer and other office staff were interested in this new affordable technology from Uncle Clive so I saved them a few quid by building the kits they ordered (by post!). They all worked fine but I remember the 16K expansion packs (or the connectors) were extremely flaky. So I used to modify the packs and replace the connectors to make them more stable ... and then came the Speccie ... I know I still have a working ZX81 in the loft. I think I'll be playing with that for a couple of weeks now!

[@LMacNeill]

The cool thing about these early computers is that the limited resources forced you to be creative in order to get anything done on them. Today the closest comparison is writing software for mobile devices - but even our mobile devices have *tons* of resources compared to these old machines. Kids who learn to program today are missing out, frankly. I like looking back at these old computers and remembering all the fun I had back then. :-)

[@Loundre3]

Not really, if your doing programming for 8bit or 16bit microcontrollers, atleast from my experience. These old computers do look tempting to program, however (atleast for me).

[@DocMicrowave]

I totally agree. You had to get real creative to get something to work within the memory space confines of these early machines. I was amazed at the kind of sound and graphics programmers squeezed out of the Commodore 64. Shifting and banking memory around. Even making use of memory in the floppy disk drive which had it's own memory and processor.

[@rickappling5470]

The same here, I have never really gotten use to partially unlimited resources. It was quite the challenge fitting something useful in 256 bytes.

[@ian_b]

@@Loundre3 Yes, for me 8/16 bit microcontrollers bring back that feel. I enjoy assembler on PICs more than I rationally should!

[@PhilipBallGarry]

Totally agree. I can't help but think that today's programmers are a bit lazy with seemingly unlimited resources 👍

[@TheronGBurrough]

Thanks for this excellent video. I'm a little older than you (born 1962) and had read about computers first in science fiction, and then in early computer magazines in the 1970s. So buying my first computer, a Timex-Sinclair ZX81, was a big deal. Many thanks to Uncle Clive for his genius, and for bringing me a computer for $99. The ZX81 immediately engrossed me and I regret circumstances separated me from it after some weeks or months. In later years, I owned a Commodore Vic-20 and I think a Commodore C-64. Then a Victor 9000, a beautifully designed and equipped MSDOS PC. When IBM released their IBM PC and its open architecture, I of course became a PC Guy. Well, at work we got IBM PCs. My first IBM clone was an AT&T PC-6300 made by Olivetti, another fine machine. To my recollection, I have not purchased a prebuilt PC since the AT&T, but have built my own from found or purchased parts.

[@your_utube]

What a trip down nostalgia lane. I bought a Timex sinclair 1000 in the mid 1980's at a flee market in downtown Johannesburg in South Africa. I was so shocked to see it standing there with perhaps two more, and fearing that they will disappear quickly, I ran to the nearest ATM and bought one. The T1000 was not my first foray into the world of computing/IT. I first encountered them in the form of a programmable calculator in the early eighties. My eldest brother was studying civil engineering and had to use one of those and it had a red LED screen and all of 50 lines you could program. Using his BASIC manual and trying out the HP calculator's own instructions (not BASIC) I wrote simple programs. By the time I encountered the T1000, I had an idea of the implication of these things. I later got a 48 ZX Spectrum and write a word processor for it in BASIC. One of the very useful features of the BASIC on the ZX Spectrum was the ability to assign a number t o a variable, and use that variable like a lable in a program. SO instead of writing 20 GOTO 200, you could write GOTO/GOSUB printdata where printdata was given the appropriate line number. That was incredibly powerful. I ended writing a decent 3-line wordprocessor that could print, save to tape load from tape and do all the needed edits. Pretty neat. Wow what a time that was. From there I ended studying Computer Science and Maths through UNISA (University of South Africa) and in 1995 I was amongst the first of about 250 people who finished the Microsoft MCSD qualification and becoming the first in Africa to Present MCSD courses as a qualified MCSD trainer. That is so long ago now. Thanks for reminding me of a pioneering era in my life. Love your channel Chris.

[@ExplainingComputers]

Thanks for this, great post. :)

[@nunyabiznez4408]

I'm in the USA but I managed to get directly from Sinclair a proper ZX81 kit delivered to my home via the Scientific American magazine ad. This was pre Sinclair selling to Timex. We didnt have access to a great many Sinclair resources in the USA so we had to build homemade keyboard and memory expansion boxes. It was good time though and the Sincair ZX 81 forced me to learn Z80 assembler, which turned into a wise career move back in those days.

[@stanpatterson5033]

A few of my friends got (Timex)Sinclairs... and I went the VIC-20 route :/ Oh well, I had color where they did not... and thanks to a neighbor up the street, I got a `blocked` 32kB expansion cartridge, and the `rabbit` system for compressing data, so that instead of taking 10-15 minutes of tape drive, it compressed it into about a 30-second wait :) Had tons of rabbit-ized games being shared around, too. Being that I was an audiophile and owned a few tapedecks, I could make quick copies from my tape to other blank tapes, even though the so-called experts said it wouldn`t work. Soon the kids who didn`t yet have a computer were going the VIC-20 route, too. Little did we know...

[@LazyCookPete]

Also my first computer. Pure nostalgia. By '86 I had graduated to a ZX Spectrum with a bog roll printer, tape deck and connected to BT Prestel - an early forerunner of the internet, using a clumsy phone cradle modem.

[@pintokitkat]

Ah yes, 300/50 modems. 300bits per second download and 50bits per second upload. And bulletin boards. Fond memories.

[@moeshickenyay]

Pete Thomas There still are still some bulletin boards out there usually remote locations with no cell service.,

[@MaraldBes]

Ow, I was so jealous of people who had the printer. It looked like such a neat device. :) I had the interface 2 (with Jetpack, the only cartridge ever made I guess) and a DK Tronics speech interface. Had to load tape for half an hour, but then I could have my speccie singing and talking.

[@und4287]

What, a printer that prints on toilet paper???

[@stevemichels5608]

I owned a ZX-80 (Sinclair 1000) - wish I still had it today! I also bought an IBM PC at the beginning of production (had to wait 6 weeks for delivery). I modified it after a few years to run a Z80 processor at 20 Mhz. I still have that MB, but it does not work any more either. Thank you, for a great look into the beginnings of Micro-Computing. My bench is now covered with PI's, Teensy's, and other Arduino compatibles. I also have a UDOO NEO and their newest X86 Ultra (just fabricating it). We have come SO FAR! Thanks again! Steve Michels, Kansas, USA

[@phillipharris758]

Was bought a ZX81 for my 7th birthday by my parents, way back in 1984, remember them giving it to me with a black and white TV and a cassette recorder. My favorite games at the time were 3D Maze and Space Invaders. Many an hour were spent reading those very magazines and trying out the different programs.

[@frank124c]

You brought back memories. I had a Timex Sinclair computer way back when. I learned how to program in BASIC with it and I wrote programs for my own use and I bought some programs on tape cassettes to play. I had a good time playing Backgammon. Great fun those old timey computers!

[@ForViewingOnly]

Thanks for this video, C.J. Barnatt of Worcester! That's an Issue 1 motherboard you have there too, with beautiful hand-drawn curved PCB traces. The 80's were a wonderful time to grow up in the UK if you were into computers.

[@chrisdechris6752]

Indeed !

[@BillAnt]

I second that! :)

[@cpcnw]

In 1982 I went to Stonehenge Free Festival - I suspect that experience expanded my mind more than technology at the time.

[@gregbarton4332]

My first computer - the Timex Sinclair 1000. I remember seeing it in an ad in Popular Electronics back in the early 80's for $99 and drooling over it. Purchased one and was off to writing my first programs! I remember getting the 16K Ram Pack for the back and thought I"d died and gone to heaven with that much computing power! It was definitely money well-spent and thanks for this video - definitely feeling a pang of nostalgia here! Keep up the great videos!

[@jeffbird2983]

The Timex Sinclair 1000 was my first PC. Even though it had no audio output. It could play music. You would run the music programs with the TV volume turned all the way up and hear the sound of the computer working. I forget the name of the person who wrote these. But they and their programs were brilliant.

[@Mrcometo]

ZX81 was my first computer too. Nice video

[@jeffdingle9677]

The Commodore Amiga 500 & 500+ were my introduction to more serious computing, after playing around on the old Commodore 64 first. Also got introduced to the BBC computer which was interesting, however preferred the Amiga 500 / 500+ as I could use Wordperfect 4.1 and print to my HP Deskjet 500. Great stuff for its time and great memories....

[@waynecyr8213]

I had the TS1000 as my first computer. I spent hours messing around with programming games into it from whatever magazines I could find. From there, I upgraded to a Tandy TRS-80 Color Computer and then to the computer that truly changed my life...the Amiga 500.

[@stevesm2010]

My first computer was a indeed ZX81 which I bought second-hand at the age of 16. I had previous experience of computers at school with the BBC Micro (in fact I was told that our school had the very first BBC Micro at the time). These machines sowed the seeds of interest that led me to buy a Sinclair Spectrum and start a life long interest in Computers and later to become Desk Side Technical Support at Reuters.

[@resrussia]

Thanks for an awesome video. My first computer was also a ZX81 which cost $99 (1983 dollars) and 16 KB RAM was $49.00. I purchased the computer sight unseen from an add in science magazine (I think was Discovery magazine published by Time-Life) from I saved from washing dishes at a summer camp between my third and fourth year of high school. Like you, the ZX81 was the computer which launched my passion for computer and using computers for instructional purposes. I was a finalist in a 1984 science fair (and recipient of an award from the local chapter of ACM) for creating simulations of Boyle's Gas Law and bacteriophage reproduction. What caught judges' eyes was the fact that the programs were written in machine code (no assembler). While developing the program, POKEd about 100 bytes instructions and data into individual memory locations by hand. Later I figured out to type use put characters represent the hexadecimal values into a string and load the machine code that way. Thanks for nostalgic trip back to a less complicated time in my life.

[@ExplainingComputers]

Thanks for this. I too coded programs on the ZX81 (and then ZX Spectrum) in raw machine code, and also got to a point where I entered characters via strings (although as I recall some hex values would not display or enter this way). This was real computing! :)

[@resrussia]

I wanted Spectrum, but the computer was never available in US. Eventually, I moved up the Timex-Sinclair 2068. I was also interest the Sinclair QL but couldn't afford the $500 price. Thanks again for the wonderful video. Keep up the good work!

[@mickelodiansurname9578]

Tom M At a time when it was possible to memorise the memory locations too...

[@flyonthewalls]

Such a legendary piece of equipment

[@DocMicrowave]

Indeed it was. I still have mine! After seeing this video I feel like digging it out, putting some voltage into it and seeing if it still boots up.

[@Clell65619]

And here, I thought we were of similar vintage, for some reason. My school district had a PDP-8 that mostly did admin and payroll functions, but they timeshared it 3 hours per week for 'computer classes', where we would happily draw out our programs on graph paper, carefully sit at the key punch and build our 'decks' (I think the largest I ever produced in class was 35 cards, next to nothing) and then wait until the next week to get our results. Then I joined the Navy and they trained me in Mainframes, maintenance/repair, not programming. My first 'personal computer' was an Altair 8800 that a buddy and I bought to play with on offcrew cycles, with the advantage that the ($400!) tape reader it had read in the same format as the MARDAN inertial nav computer, so we could build our programs using the ship's tape punch system when it wasn't being used for mission related things. Then my buddy went Apple fan boy when the Apple II came out and I went TRS-80 with a series of machines until I got a modern PC in 92 or so. God, I'm old.

[@kevinstrade2752]

Being an American growing up in the 70's & 80's I never heard if this machine. my first computer was an Atari 65XE. I learned some very basic programing, very basic. I am not that good at it at all. but still, computers were a type of canvas for young kids of the day. kids could build and create something entirely with thier own creativity and hands. back in the day there seemed no limit. as an adult I have grown an appreciation of these early computers. I do still have my Atari line of computers of course, but I have expanded beyond to see what others had to offer at the time. I have watched and read articles on Sinclair and thier early efforts. I found the history fascinating. we didn't have much of a micro market here but they are still interesting. Clive Sinclair put computing and endless futures into the hands of 2 million Brits. I recently picked up a timex 1000 and look forward to seriously giving it a try.

[@lwaves]

Hi, my name is lwaves and I'm a ZX81 survivor. ZX81 was my first computer too but I may have had a very different experience than most of you. Let's call this my therapy session. It may be wordy for some. In Oct of '82 a mate got a ZX Spectrum 48K. It was great and by then the ZX81 was something of a joke (basically a door wedge), it was already infamous compared to others at the time. So, I constantly mentioned it to my parents in the hope of getting one for Xmas. First Xmas came and went but the following ('83) I started unwrapping and when I saw Sinclair my heart skipped with excitement. Then I saw ZX81 and my world fell apart. I don't know if I hid my disappointment well or not but they said that it cost them a lot so we (it was a share with my younger brother) had to be careful with it. Inside I already hated it and the fact that they'd bought me what was effectively crap compared to the Speccy. Part of me also realised that they knew nothing about computers and had probably been ripped off by the seller as I don't think it was brand new. Eventually Boxing Day came around and I knew that I had to set it up and use it, partly because my brother was asking and he was none the wiser about computers too. So I did, programmed a few games in over the afternoon and 'played' them as much as you could within the limitations. But I knew the worst was still to come. A couple more days go by and I meet up with my mates where I have to tell them what I got. I can still hear the laughter now. I had the piss taken out of me for so, so long after that. Worst. Xmas. Ever. I hated that I felt forced into using it for quite some time after that. My parents were (are) good and I didn't want them to feel bad for buying crap. Thankfully, by the next Xmas I managed to still mention that I wanted a Speccy and espoused the virtues of the better machine, so that when the Speccy+ arrived in '84 we recieved one for the following Xmas and all was right again with the world. Some people mocked the plastic keys (isn't that strange?) but even then I much preferred it to the rubber keys. I finally had a Speccy and this led to Amiga's and eventually PC. This is my story. The end.

[@RobA500]

The ZX81 was my first computer as well and was upgraded to 16k using a Memotech ram pack. It also got a full sized keyboard, hi-res graphics & sound curtesy of Maplin kits. Best of all I still have it and it still all works.

[@ExplainingComputers]

Fantastic to hear that it still works! :) I have not heard the word "Memotech" for such a long time . . .

[@robwebnoid5763]

Here in 2023. As a teen, I remember playing around with these (in the US), as they were floor demos at department stores, for a little bit in the early 1980's. As much as I was tempted to get one, because of the price, I eventually just did a bit more research & eventually got the C-64 for $299usd (bought by my parents), which in those early days was unbeknownst to all of us that the C-64 would eventually hold the Guinness record title of being the world's first favorite multi-million sold personal computer. I did see all those Memotech expansion paks for the Timex Sinclair in some computer magazines of the day & those too kind of made me drool of the potential of expanding a TS1000, but in the end, I just focused more on the C-64 & then to the Intel PC. I still have 3 C-64's in my possession, with one of them being my first C-64 & first computer ever. Glad that I did not throw it away. But I still respect the TS1000 for being an early consumer mass market computer. But sometimes, trying to be cheaper in price but also cheaper in features doesn't always add up to what buyers would want in a computer, thus why the Intel/IBM PC eventually won the war. Hopefully the ZX81 in the video has since been repaired.

[@prawnmikus]

The ZX80 was my first computer, built from a kit. I've kept all my other machines since then -- took the Commodore route -- and seriously regret selling the '80. It got me into programming at a very young age and once I'd made the leap to the C64, I was ready to dive right into machine language. Fun times, but man, I wish I could teleport some money back to my young self! To think of all the fun gadgets I could have played with rather than drooling onto magazine pages over.

[@davidlovy1271]

One of the first computers I used extensively was the TRS-80 Model I, but the first computer I owned was the Sinclair ZX81. I spent hours, days and weeks during college making it do things the bigger computers could do. My favorite was solving equations using matrices. I could solve a 5 x 5 matrix and display the result in 1K RAM by minimizing the display output. I eventually got the 16KB RAM pack and bought the flight simulator program for it. I was impressed that with such low resolution, it provided a very realistic and accurate experience for landing on a runway at night. I still have it stored somewhere and it worked last time I used it, but I need to find a power supply and an analog TV to use it again. Thanks for the link to the simulator.

[@joseph7858]

Chris, thank you for this contribution! And yes: the ZX81 was my first, too! Fond memories, me sitting in front of that machine, figuring out programming hickups! :-) Warm regards, Joseph

[@srg0075]

The ZX81 did it for me too, but I had to walk to school for several months, and for go lunch, to save the bus and lunch money to get mine, actually I was saving up for a ZX80, I was about 70% there, when the ZX81 was released (ready made as well) and it was 30% cheaper, so I ordered it that first week - It's now in my display cabinet! Thanks for the great videos.

[@GabrielDubatti]

I'm 51 now. I learned how to program in assembly in the very old RCA COSMAC VIP: oldcomputers.net/rca-cosmac-vip.html (with just an hexadecimal keyboard, who needs more?) when I was 15. A friend of mine had a ZX81 and I remember being very impressed when I saw it. Later I had a Radio Shack's COlor COmputer. In 1985 I bought my first PC clone (12MHz NEC V20, no hard disk, 512MB ram, 2 floppys, Hercules graphics card) ... so many good memories! Love your "classic" videos.

[@MicrobyteAlan]

In 1981 I was a field service engineer fixing DECsystem 20’s. My big influence was Star Trek, first run back in the mid ‘60’s. You’re a great explainer. Thanks

[@stuartofblyth]

My first computer, which I still have, was the Rolls Royce of the genre in the early 1980s - the BBC Model B. It wasn't until 1990, though, that I got a program published (a lunar eclipse predictor) which earned me £98 - a considerable sum in those days. www.acornelectron.co.uk/mags/mu/ills/090/sc-p043.jpg I have a ZX81 languishing in a cupboard upstairs. I bought it to automate our central heating system. The wall-mounted boiler was in the kitchen so that's where the ZX81 had to go. Regrettably, the spark ignition on the nearby cooker hob caused enough electronic mayhem for it to crash every time, so that was the end of that particular project.

[@xaba_simracing]

ZX81 was also the first computer I encountered. That moment influenced my whole life. Currently I am a Java programmer but in my kid ages I wrote games and demos in Assembly on ZX Spectrum and later Enterprise 128k and finally on Amiga 500. 😀 Nice memories!

[@darkstarnh]

My first computer too. Bought it on my 21st birthday in 1981 and fitted it into a Memotech after market keyboard case. I found the old original case recently and, with the addition of a clock mechanism it now makes a stylish wall clock!

[@geertvancompernolle2586]

Seeing this makes me "melancholic nostalgic"... ZX81 was also my first "encounter" with something related to computers. I even made my thesis based on a Z80 microprocessor. The Z80 was not a microcontroller, oh no... You had to connect PIO's (for parallel I/O) and SIO's (for serial I/O) to it to get something from or to the outside world. Later on, I bought the ZX Spectrum and waaw.... That was colour!!! Unbelievable at that time. That one had a slightly bettery keyboard (rubber buttons they were) but still, I had to make a keyboard myself since also the "slightly better" keyboard (compared to the membrame one of the ZX81) went to walhalla after a while... Still remember vividly the hours I spent playing with those toys. Also still remember my parents didn't understand anything of it while I was programming the thing... "What on earth are you doing with that black box" was a question they constantly asked... Never gave a reasonable answer, I must admit...

[@paulchamberlain8636]

Brings back memories of my first computer the Timex Sinclair 1000.

[@FlemmingDidriksen]

I started on the ZX81 too. My father purchased it (1983) in a bookstore and not long after we bought a 16Kb expansion. I bought a lot of magazines and typed into the ZX81. At the end of its run, the keyboard was tired down and one wrong touch could reset the computer. Not fun when you had typed a lot of code. :-) I moved on to the C64 in 1984/85. The biggest game I typed in was "Phoenix Tower", from a magazine. Maybe somebody remembers that one ;-)

[@c0y0teX]

The first computer my grandpa brought home was a Commodore vic 20 back in 1988 I still have it, after that he brought a Commodore 64. We learned Basic together, also from magazines, I was 8 years old and Guatemalan, l was so lucky to have access to that technology.

[@MarkKeightley]

The Sinclair ZX Spectrum was my actual first machine, but I consider my second machine, an Atari STE to be my first ‘real’ machine. It was the first machine I programmed in the C language on.

[@aemvasconcelos]

I used Hisoft Pascal for the spectrum quite a lot, much faster than BASIC for drawing Mandelbrot graphics. I tried Hisoft C but I wasn't able to "decode" the language from the manuals. "The C programming language" book was quite a few years in my future.

[@MaraldBes]

I wish I picked up C when I had my ST/STE/TT's . Would have helped my C# issues I have nowadays. I used GFA Basic a lot, which was the first programming language I learned that didn't have line numbers :)

[@DocMicrowave]

Ah, an Atari User! I remember some interesting debates between Atarians and Commodorians. I was among the later.

[@r.a.monigold9789]

I had one. Cassette storage was super hi-tech, providing hours of fun waiting for the programs to load. Nice memory flog. Thanks for sharing...

[@raccoona.matata1039]

This was also my first computer and also bought by my parents as a Christmas present. I still have it in the original box with the manual. (Timex Sinclair). I've also got a number of Commodore 64's, although I ended up working with mainframes for many years. Now I'm back in school learning new technologies and I've recently acquired a Raspberry Pi which brought me to your videos in the first place. Thank you for the videos and happy surprise of finding someone else who remembers the initial excitement of having the doors of possibilities flung wide open.

[@ExplainingComputers]

Great post -- thanks for sharing this.

[@aldebap]

Back to 1984, in my 14th anniversary, my dad gave me a TK-83, a brazilian version of ZX81, with 2K of memory and a 16K expansion. In that very day, prior to finish reading the whole BASIC manual, I wrote my very first computer program. Using this awesome computer I also learned Assembly Z80 and Forth languages. These were the first steps to a 30 years successful carrer in computer science. Thanks a lot for the video to revive those memories.

[@RetroBerner]

We had a c64 growing up. My mother and I scrounged together parts from the trash and we figured out how to program it together.

[@thomjones9719]

Steve Martino Tell us more! Sounds like a great story! (C64 was my 2nd - still can name my fav games 😅😂)

[@TheNZJester]

My 3rd computer was a C64 after the Sinclair ZX81 and Sinclair ZX Spectrum computers I had.

[@CJ-rf9jm]

My 1st was also a C64 in fact I went out n got another 15 years ago to tinker with in spare time, have more for it now than I did when it was new. btw to the person who had the Ohio Scientific I have heard of those, people were into those a fair bit where I lived.

[@brokensilence6790]

Steve Martino, So you're not making this up? Your Mum went through skips (dumpsters if you're american) and knew exactly which chips to choose in order to put a computer together? and then 'figured out how to program it together' BULLSHIT.

[@PeteVanDemark]

I suspect they probably scrounged working modules like a power supply, printer, or other peripherals. I don't think Steve implied they did a board level build. But who knows? Maybe his Mum worked at IBM or NASA and was an EE. You never know...

[@AtomicShrimp]

Ahhh, I had that exact same keyboard for my ZX81 - I initially only bought it because I first installed an add-on that made the inverse text characters user-definable (like they are on the Speccy), but this add on board just sort of sat off to one side of the ZX81 with a ribbon cable entering the side of the machine (so the Fuller keyboard had space for everything inside) I miss that computer.

[@olebak0]

My first computer was a ZX Spectrum 16K, later upgraded to 48K. I spent a lot of my teenage time with that machine. I started out learning Basic, and succeded in selling a simple game written in Basic to the bookstore in my local town, which was running as a demo in the store window :-) Later I got into Z80 assembler coding, and bought The Complete Spectrum ROM Disassembly, learning all about the "OS". One of my friends was good with hardware, and one of our most advanced projects was getting the Spectrum to work as a MIDI drum machine. He designed a MIDI interface and DA converter, which was plugged into the expansion port, and I wrote a program that could play 2 drum sounds simultatiously. I had to use only the upper 32K for program and sounds, since the lower 32K was apparently shared with some hardware reading the display buffer, which made it implossible to maintain a specific pitch when playing back sounds through the DA converter. Thanks for the blast from the past, I really like your channel. Kind regards, Ole, Denmark

[@olebak0]

My Specrum also underwent a transplant to a full keyboard, since the rubber keys tended to wear down the keyboard membrane. I still have the computer, and have put it back in the original case, but alas, it does not seem to work any longer.

[@slodown3670]

Many thanks Chris. This took me back 40 years to when my son was born. My 'programming' was done in the middle of the night while he slept!

[@ExplainingComputers]

:)

[@MartinBgelund]

My first home computer was a Lambda 8300, which was a ZX81 clone, so I could actually use ZX81 programs. Those were the days!!

[@ManuRu1z]

My first computer too!! BTW, what a wonderful channel. Greetings from Spain Chris.

[@AllyJC]

My ZX81 would crash constantly thanks to the dodgy memory pack. Copious amounts of sellotape were needed to make it function. Despite moving on to a CPC, I always was fond of the ZX81. It's so awesome to hear of someone who has submitted type ins. I was always in awe of the people who sent in that voodoo code for us to chug away with. The most hated message I can always remember was "Data Error", usually caused by "User Error". Thanks for the video.

[@frenchytravel]

My first computer was also a ZX81 with RAM extension. A lot of memories ... second computer was an Apple IIe ... Unfortunately they didn’t survive. Thank you for bringing us back in time :)

[@giovannip.1433]

A friend of mine had one- back then it was eye opening stuff- especially because you could get it to 'do stuff'..

[@richardcreese]

Wow, this brings back (1k) memories.

[@ExplainingComputers]

We had to remember things more efficiently back then! :)

[@your_utube]

I bought a TS1000 from a flee market in Johannesburg, South Africa in the mid '80s with a 16k ram expansion module. A year or two later I bought a brand new Spectrum 48k. I had the UHF modulator disabled and bypassed and the pure composite video output could be used via an AV connector to a PAL (625 line) monitor I also bought later. Still later I bought a printer and a parallel port connector cable, but had to buy a Centronics interface connector to be able to connect the printer to it. I had to write my own 3-line word processor editor in basic. I called it my periscope editor. A full screen editor was to slow because you had to watch it build up the screen line by line so slow it was. I could insert lines words, make them bold and delete letters, words, lines. In addition, I could save and reload my files to and from tape and print them. It was unbelievable. It launched me into my former career in IT and as first qualified MCSD trainer in Africa. I feel such nostalgia today. Thanks for bringing back those memories.

[@ExplainingComputers]

Great post, thanks for sharing.

[@chroniclesofbap6170]

The genius of making the power-in socket the same form as the headphone and mic socket. No danger of anything going wrong there.

[@brokensilence6790]

BBC Micro Model B. I was 13, and my Dad worked on big Ferranti Mainframes for the MOD -Winchester Disks and Banks of Processing in rows filling up huge rooms to drive the Ship Simulators for the Royal Navy. My Mum and Dad wanted my Sister and I to learn programming (BASIC and Assembly Language), but I just learned enough code to hack Machine Code 'protected' games; anyone remember *OPT 1,2 *OPT LOAD "(Program Name)"?, it was a way around that 'SAVE=BAD PROGRAM' issue. Then 'Elite' came out, and I was emerged in that until I left school, at which point I spiked my hair up and got a guitar and was away from computers until about six years ago. Now I record music on my self build PC, and play Elite Dangerous -kind of a full circle really.

[@MalcolmCrabbe]

I too had a ZX81 as my first computer. I purchased it in kit form for £49.99 from WH Smiths, built it and it worked first time. I too ended up fitting a "real" keyboard, and placed the PSU and 16K ram pack (3rd party not the awful OEM one) into a case purchased from Maplins. I ended up buying a few more kits, and then flogging them to friends for £5 less than the £69.99 retail price in Smiths... which made enough cash to buy a few games. The game I played the most was Startrek, which had the full 8x8 galaxy, Klingons, Bases, and even black holes... all in 1K !!

[@gregthompson7793]

My first computer was the timex Sinclair 1000. Loved learning to program on that little machine.

[@highcountryrider]

I think the machine that got me hooked was an HP 9100A programmable desktop calculator. It was loaned to my high school somewhere in the 1967-69 period. I was fascinated that I could figure out how to solve a physics or math problem, write some code to do that, and the machine could solve the problem repeatedly for different variables. It took away the tedium of doing the calculations for each set of data. It had conditional branching, allowing complex programs.

[@BjoernMueller]

woohoo ye olde ZX81 .:) Was my first computer as well. Got my dad's old ZX81 in 1984 for my 6th birthday when my dad moved on to ATARI 600XL. Mine was in a "lovely" vomit-green plywood case my dad built with 16k or 64k ram. Fun times... one day i'll find the transport-simulator type game i played the most on that one.

[@MrTabs64]

Yes, my first computer too. And lets face it, the price was a huge influence. I learned basic on a commodore pet at school and wanted something I could use at home. I eventually went on to a spectrum and even the ill fated QL. This all lead to a 25 year career as a programmer.

[@ExplainingComputers]

Great to hear. I too went ZX81, Spectrum and QL. The latter was a great machine. A pity the BBC skewed the market.

[@r0bhumm]

@@ExplainingComputers I never did get hold of a QL though I was desperate for one at the time, instead I ended up with an Atari ST as the next computer after my spectrum which I don’t really regret.

[@joehumblestud9513]

The TS 1000 was the first PC I ever bought back in college, on closeout. $20 USD for the TS 1000, and another $20 for the 16K expansion pack. I programmed on it a lot, and eventually wrote a weather simulation program that took up almost all the memory. It was great fun, and I eventually moved on to the Commodore 64 before beginning to repair actual IBM PCs and clones for a living.

[@stanwbaker]

TS-1000 was the first computer I owned. I am always charmed and nostalgic when they pop up, mostly on KZbin these days. The survival rate was tragic. When mine was resigned to the attic, the next time I saw one was at the Dell Museum in Austin, Texas in the late 90s.

[@rafalg2113]

Who would ever need more than 16kb of RAM? That would be insane ;)

[@mhamedali2181]

I see what you did there

[@mserogul]

Why not; first I had 16K, started to write Z80 Assembler in Basic, 16K was not enough so I got 64K Memopack :) by design 0-8K was occupied by ROM, 8-16K unused, user area was 16K up. Wrote small usr's which moved to 8-16K area at first boot and used 16-64K area as 3 16K partitions to load 3 different programs, swap partitions and run. It was fantastic at 1982-83.

[@stevemichels5608]

Quite interesting projects you were doing mserogul! Yes... I thought I would NEVER run out of RAM when I expanded my 4K IBM PC with a 12K expansion board to raise the bar to 16! Now I,m distressed if I do not have 8 or more Gigs! Amazing! Oh, and don't even mention the 8 TERRA-BYTE RAID system I now have for 1 of my systems. I thought that 500 Meg was HUGE, once upon a time! LOL!!!

[@AndyWJP]

Yeah. I started with a ZX81 with a 16K RAM pack and now my current PC has 1 million times more RAM (16GB).

[@BillAnt]

Or one could NEVER fill up the C64's 64KB memory, it was expansive!! lol

[@andrewsmactips]

I had a ZX81 for a short time. I remember taking it apart and burning my finger on that innocent looking heat sink.

[@IanHodgetts]

My first computer too (at age 10) and I recall typing in "Laser Cannon" from that very magazine! I wish I still had a copy for the nostalgia. I did end up writing a few of my own games but never thought of getting them published.

[@jlfqam]

ZX81 was also my first Personal Computer. With it I learned basic, assembler, binary and hexadecimal arithmetic, and pascal. After filling up the original 1K of RAM with basic code, I had to buy the 16KB expansion. The knowledge of how a simple computer works, gave me an extra sense that helped me in the use and especially to troubleshoot more complex software and advanced computers. In the 1980s, working with computers was so hard and time consuming that few people could imagine such gadgets could change the way we live nowadays. Thanks for this posting.

[@karllaun2427]

I started out on a TI-99 4A, then TRS80. After that, a long series of Commodores; C-64, C-128, Amiga 2000, 3000, 4000.

[@ExplainingComputers]

Wow, that is a long series of Commodore machines. They were nice computers.

[@billfusionenterprise]

no sx-64?

[@karllaun2427]

or VIC-20

[@billfusionenterprise]

my buddy had that with the cassette drive

[@RobertLock1978]

The TI was my first machine, too. Quirky thing ;D

[@AnimalFacts]

That aftermarket case would be fun to put a Raspberry Pi into.

[@TheNZJester]

I wonder if the keyboard could be hooked up to the GPIO header to support using it for the ZX Spectrum emulator in RetroPi?

[@ufohunter3688]

For sure.

[@medworthy]

+Animal Facts, Funny you mentioned that. I was passing a seconded hand electronics store about a week ago and actually saw a ZX81 case with a Raspberry installed within it. The store was asking around £45 (GBP) / $60 (USD - approximately) for this device.

[@AnimalFacts]

@TheNZJester Don't see why not with a little programming. You'd just be simply scanning a matrix.

[@AnimalFacts]

I've been itching to get my fingers on a broken VIC20 or C16 for that.

[@djsherz]

Our first family computer was a ZX81, and like yours, it was re-mounted in a better case along with a 16K RAM pack and some sort of graphics expansion gubbins. By the end of the 80s I'd acquired a broken Spectrum off a mate at school, the rubber keyboard was knackered and it didn't power up. I replaced the 5V regulator IC, and mounted the board inside the ZX81 keyboard case, before re-wiring the keyboard to make it compatible with a Speccy motherboard. Sinclair made some great innovative stuff, but sometimes too many corners were cut to keep costs down. The factory keyboards were legendarily cack, and the voltage regulators were notorious for failing, due to not enough heatsinking inside the case, something which was addressed in the later spectrums. An extra lump of aluminium bolted onto the heatsink kept mine running cool for years.

[@robintst]

The Timex Sinclair 1000 was my brother's first computer. His dad ordered it for him out of the back of a magazine to see if he was really going to stick with learning computers and that pretty much set his future career path in motion, he's worked for several software companies including IBM. He still has that TS1000 and keeps out as decoration on his desk.

[@ptonpc]

ZX81 first but i much preferred the Spectrum 48K.

[@chrisdechris6752]

Oh hell YES!!!!!!! Those games 😍😍😍😍😍😍😍😍😍😍😍😍😍

[@exeqt]

I have to say C64, not so much programming, but som gaming. I still have a robotarm you could connect to C64 joystick or to an interface to be run by the C64 and programmed by the user.

[@redrobbosworkshop]

Excellent video Chris. I had a XZ81 as a boy and together with the slightly later ZX Spectrum learnt BASIC programming at school using these machines. I have fond memories of loading up the cassette tape based software, less fond memories of typing pages and pages of code from those magazines! IIRC the very first computer I used at school was a Research Machines 380Z - a large 19" rack mount case unit which would be connected to one of those old B&W school TVs - the ones mounted atop a tall poll with fold out doors to cover the screen. Happy days! Rob

[@zebratangozebra]

Bought one of these back in around 1982 in the US. It was for sale in Popular Electronics magazine as a kit for $99.99. Learned how to program in basic and a fair amount about assembly although I couldn't figure out why I couldn't write to some memory addresses, (it was the ROM memory) LOL. We didn't have those magazines you showed here in the states but we did have one magazine that I bought every copy of (can't remember the name). I learned a lot from the ZX81. Thanks Clive.

[@BrokeMansPC]

80s Raspberry Pi? Nice!

[@maicod]

this one was non-edible

[@innstikk]

For me it was the Memotech 512 that I got when I was 10 years old. Remember that I wrote a program to help me memorise English words that we learnt in school. Learnt coding in BASIC and later in better languages :-)

[@seraphinberktold7087]

My first computer was a ZX Spectrum with a whopping 48 kB. It started my career as a software developer and project manager. I still have to publish my Latin verb grammer trainer to the unsuspecting public. I acquired a German ZX81 package some 2 years ago. It's a fascinating machine, too. An exercise in minimalism and a triumph in engineering. RIP Sir Clive!

[@ilovealbundy]

Wow, nice to see this little computer again! This was also my first computer and I still remember how fascinated I was with it. Later I bought a memory expansion and the printer. Thank you for creating and uploading this video. This video is again a real highlight, like all your videos by the way. I love your channel!👍

[@ExplainingComputers]

:)

[@123rkss]

that was a pretty rare thing. the cleaning lady almost fainted when she saw that connected to the tv in our hotel room during a vacation. she thought my dad was a spy or something

[@DimusTech]

Well sadly my first computer wasn't that cool. When I was in second grade (age 8) I asked my parents for my birthday a new Lego set as I really loved Lego, but my parents decided it will be better for me to get a computer and got me a Pentium 1 which had back then Norton Commander installed, a friend of the family that new how to use computers installed some games for me and few weeks later I had Windows 95, then 98 and then I collected enough knowledge to install OS's myself, and got my hands somewhat dirty with hardware as well. Sadly I didn't have such good educative opportunity as the ZX81

[@herrfriberger5]

Yes. The Pentium of 1993 was a super computer compared to the Z80 or 6502 (Sinclair or Commodore). I mean it literally, it was thousands of times as fast.

[@DocMicrowave]

@@herrfriberger5 Funny thing though, through the 80s into the early 90's, even with PCs starting to take root with consumers, the Commodore 64 was still the most popular consumer computer on the planet!

[@elektron2kim666]

I bought the ZX-Spectrum in '83 or so as a teenager. It helped me in life to value a hobby.

[@kennethflorek8532]

The first computer I owned was built from what used to be called a development kit. (I was in the midst of a 4 year course in electronics.) The wonderful advantage in that era (about 1977) of development kits to experimenters having a normal income was that that it cost less than just the the CPU chip it included. (To stimulate designing with microcomputer chips.) The CPU in this one was an F8 by Fairchild, although the chip was manufactured by their second source, Mostek. This kit with 1K of memory, where you soldered sockets on circuit board and plugged in the chips, had been selling for (I think) $250, but sales had not gone well, and a mail-order electronic parts dealer (Jameco) picked them up as surplus, selling them for (I think) $80. ($80 would be something like $300 today.) They also sold the other things needed to minimally get the thing going (if you didn't have a teletype): surplus CC monitor less any case ($120?), bare keyboard($60?), and power supply ($30?). What used to be called a "monitor" program was in ROM, so you could enter hexadecimal into memory and watch the F8 execute instructions, dump registers, etc. Optionally, you could buy BASIC on paper tape, and an optical paper tape reader, and have the monitor program load it into memory as you pulled the tape through. I should say that I, like most experimenters, already had conclusively determined, reading Popular Electronics about things like the Altair 8080, that computers were essentially useless for any purpose to an average person, so this kit did NOT come as a disappoint whatsoever. I had learned (in technical school) the basis of computers as being a logic machine. Being able to directly manipulate such a device with my own hands, and watch it in all detail, was what drew me. I had no interest in getting it to do anything as boring and senseless as a computer game (pong?), or anything of that sort.

[@sausage4mash]

we had a zx80 none of that new fangled memory mapped screen

[@TheTechGuyYT]

I stiĺl need to get a ZX81

[@12dollarsand78cents]

I still have one I built in 1983.

[@lihourj]

My first computer. My dad bought a second hand ZX81 in 1982. I think we got the 16k RAM pack eventually then bought a new ZX Spectrum with 16k. We later got a used 48k RAM pack and the Sinclair printer which used the silver coloured thermally sensitive paper. I remember trying to type in programmes from magazines but don't recall ever getting them to work. Nor did we ever manage to successfully save and retrieve data with the cassette recorder. Nevertheless this was a great introduction to computers and I enjoyed playing games on the Spectrum.

[@johnvirgin405]

Hi Chris, Just a quick message to say a huge thanks for the all the content you post. My introduction to computing was the ZX81 and I have fond memories of copying out Basic computer code from magazines such as Sinclair programs. Now rapidly approaching my half century I have used the enforced lock down of the past year to rekindle the enjoyment of making/coding stuff for myself through the raspberry pi. I am currently taking inspiration from your weather station project. So again big thanks for all your content. J

[@ExplainingComputers]

Great to hear this. Good luck with your Pi projects.

[@ypey1]

I was an atari xl boy

[@Djuntas]

10:56 Damn slow down, last bit blew my mind ^^

[@tonyelsom6382]

When I saw a friend showing off the ZX81 in 1982, I wanted one right away, but he told me to wait for the ZX Spectrum that was due in a month or so..I duly went ahead and bought a small color tv anticipating the release.Three years down the line I had it in a dktronics keyboard, Disciple disk interface with two stiffy drives, large Epson compatible printer, joystick interface, Currah microspeech etc, etc..all interconnected though my hi fi sys of the time..I stuck to this until my first pc xt/at compatible in the late 80's.. 😁

[@DuhBiggestDog]

Been a subscriber of yours for several years. Don't know how I missed this goodie. ZX81 was also my first computer. Had the expansion memory block plugged into the back. Wrote a bunch of stuff and stored it to cassette tape. My best was a Destroyer dropping depth charges on a sub. Even displayed "Boom" when you hit it. I don't remember what I did with my Sinclair. Now you have me on a hunt. Great stuff and professionally done. 👍👍

[@ExplainingComputers]

I hope you find it -- and that, unlike mine, it still works. Thanks for being a long-term subscriber.