ZX Spectrum | Cheap as Chips
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Update: The Spectrum is repaired, but all it took was some new capacitors before I attempted any interesting fault finding. So this series will now be taking a different direction exploring what made the system unique.
I was donated a rather handsome 48KB ZX Spectrum by Mrs ManCave's father this week. Owing to its cosmetic condition we can hardly make this a "Trash to Treasure" series, but it is in a none-working condition. Let's start by taking a look at the system before we move on to repairs, and the use of the machine in the modern day.
Music Credits:
"U make me feel" - MK2
"See you soon" - Otis Mcdonald
Dance, Don't Delay by Twin Musicom is licensed under a Creative Commons Attribution license (creativecommons.org/licenses/...)
Source: www.twinmusicom.org/song/303/d...
Artist: www.twinmusicom.org
"Secret Conversations" - The 126ers - Věda a technologie
My first computer. The buzz on Christmas Day in 1983 when I unboxed my Spectrum hasn't been beaten. I'm going to cry.
And mine as well. I got the dreaded blue smoked power supply about 2 years in.. then the keyboard went.
I also had a “weird” keyboard which seemed three times stiffer than all the machines my friends owned (6 others that I tried) wonder whether that was unique to mine…?
@@mhoppy6639 Was it a 128K? I know some of the grey models had a different spring length for the keys
Using one half of broken RAM chips is hilarious and amazing, the cost-cutting measures on this machine are legendary. And it's amazing how much could be done with a few off the shelf parts, a single custom IC (or a ULA, close enough) and a whole lot of smart engineering.
Price was the magical ingredient that made it succeed, they did get to 128k eventually.
I think the boys over in Wales did something similar with the Dragon 32.
Used to run a computer repair shop back in the 80’s.
Loved the Sinclair products as they provided a constant stream of work.
Biggest problem with the ZX Spectrum was the ZTX651 transistor that provided the negative supply to the RAMs, this would frequently blow and one or more RAMS would fry as a consequence.
Tremendous clear photography. Thanks for the tour of this classic beast of a machine.
I had a 48K Spectrum back in the day and I still have a Plus 2 in the loft (along with a BBC Model B). I still fire up the emulator from time to time. Sir Clive was known for his cost cutting (I think it was his ethos) and he passed his savings on to the customers. The rubber keyboard never bothered me back then.
That sound instantly turns me 10 years old again! Glorious!
Wonderful days. I used to fix these and the C64 at a local computer shop in the late 80s. My speccy in the 80s had ic sockets fitted, so upgrading from 16k to 46k was so easy. My dad worked for Crosfield Electronics in Peterborough, so ic's were so cheap (even free). Great video. Precious memories. Subbed!
y_m_o i remember crossfield, i used to operate their scanners , kevin and Gary were a couple of the engineers there :)
The Spectrum was true ghetto technology on every level.
Amazingly, that didn't stop it from being the most popular UK home computer in the 80's.
+reggiep75 I think that's the best description I've ever heard of a Spectrum
Look at the raspberry pi, when we engineer down to a cost we make things extremely popular.
First video from your channel I watched. I like that you take the time to explain everything well, have a nice voice to listen to, and that the background music is exactly that - background music. I'm certainly watching more!
Thank you and welcome to the cave
Great stuff! Your videos are at the top for vintage computers as far as im concerned.
Well done, great high quality content for this cute loveable little bugger of a system!
Great tour of the speccy, thanks for doing this! I grew up on the ZX Spectrum (or rather, a Portuguese Timex 2048 clone), from the time of Crash and Microhobby magazines, so this brought back memories :) Awesome restoration videos, subscribed and looking forward to seeing more!
Superb video thank you Mr RetroManCave, I've had a 16K Issue 2 Speccy since new and always wondered about the transistor on the Z80!
It looks mint! Beautiful! It's a great review you did here.
This is the GOAT of British micros.
Brilliant wee film - very insightful, thanks.
Those transformers gave approx 14 Volts (unloaded) already in the 1980s, so not faulty. On the other hand, the 220V was raised to 230V and then again to 240V where I live (and probably in other countries as well). So these 14 volts then became approx 15 volts, giving that old 7805 regulator in the ZX's even more headache than before. (The best you could do is to replace that 7805 with a modern switched regulator in a similar casing.)
I love your channel , very educational.
Oh how lovely to find this channel. I came over from EEVBlog, which I noticed I never watched a whole video through anymore, which can happen I guess. This channel goes where I hoped EEV went more often. Thanks!
Thank you that's kind. Love EVBlog. That is one very excited man
He is very excited and I do love the tech, just not the other stuff. This channel seems more relaxed I noticed. :)
This channel deserves to grow!
Very kind thank you... Part 2 of this is now in progress
What a beauty. Shame we never got the ZX in the US. For what it is, it's a great little machine, and the creativity the game programmers had to use to bypass it's limitations was incredibly impressive. I do have a Timex Sinclair, though. Gotta get me a ZX some day.
To get it running in the US you'll need a 9V power supply (centre pin negative) and you'll need to change the crystal oscillator and something else, there's NTSC kits for the Speccy on the web that are cheap, you can also buy harlequin kits to custom make your own with new parts since someone has managed to reverse engineer parts and remade cases, keyboard membranes etc... I can help you if you do get one some day. I own 3 myself.
The british home computer market from the 80's is a sight to behold.
A large majority of the best home computer games from the era, even for the American designed systems like the Atari 8 bits, c64 and Amiga were from the UK or parts of Europe.
Though the PAL systems had a weird accidental technical advantage... The consequences of which were especially apparent in the Amiga...
But it was a quirk common to everything from the c64 and Atari 800 to even the 16 bit consoles like the Mega Drive and SNES.
The Amiga developers in particular abused the hell out of that advantage, which made ports from PAL to NTSC machines a nightmare.
The home consoles meanwhile tended to optimise for NTSC systems, which left PAL gamers with slowdown, and black bars on their graphics. (even though, like the Amiga and c64 and most other systems, the 16 bit consoles had their own version of the PAL technical advantage.)
The PAL advantage is entirely accidental but quite significant - It comes from PAL being 625 interlaced lines 50 hz, and NTSC being interlaced 525 lines, 60 hz. (for non interlaced display, which is possible due to abusing the signal standard it turns into 312 and 262 lines respectively)
The lower framerate is a minor contributor, but the big advantage is extra lines.
Since the line count includes the screen blanking time, but the resolutions of both systems are usually the same for most home computers, you find that the PAL system has a much longer blanking period than the NTSC one.
This means you have way more time in which the CPU can mess with the system's graphics than you do on NTSC.
What this translates to and how you can use it varies enormously per system, but in some cases you have more than 3 times the effective memory bandwidth to cram graphics from the CPU into the graphics memory...
This makes a big difference when doing things that exceed what the system's graphics chip can do independently.
Which for most of those systems is really quite limited.
Ah... Going off on a tangent again.
I miss those old systems.
Probably why I'm in the middle of writing games on retro hardware right now. XD
actually, we kinda did..it was called the Timex/Sinclair 2068
There also was a upgraded version of the Timex/Sinclair 1000 called the Timex/Sinclair 1500....basically a T/S 1000 in a Spectrum case(without the color legends-just like the 1000, this was a monochrome machine).
I have a PAL Spectrum and it works just fine with a new power supply and a composite modification. It feeds into my U.S. Spec. LED flat screen TV. The TV automatically adjusted to the computer output and displayed it normally, unlike my CRT TV which would not do so.
Excellent video. Very clearly explained.
Nice comprehensive overview =D
Just got a spectrum and an apple II europlus with my own background being more amiga and dragon 64 based, this video will be really useful when i take a look inside the unit.
I wish there was more content online about the europlus....
That is one beautiful Speccy. Even in a non-working stat a gem.
Not bad at all is it. It also came with the ZX Printer which hasn't ever had a plug put on the power supply. I'll hopefully demonstrate that soon
Never had one. I had the mighty Sinclair (*cough* Amstrad *cough*) Spectrum 128k +3. Which I loved and will be re-buying one. But I always loved the 48k my mates had. Oh that rubber keyboard. Nothing else is like it. I may buy one as well.
fantastic video. so glad i have subscribed!!
I had one of these. Manic Miner was the best game ever! I've still got mines. It's in great condition as well.
Great video. Didn't know much about this computer and all of it's (character giving?) flaws. No wonder Sinclair wasn't popular outside the UK.
The Spectrum was very popular outside of the uk.
Oh another channel that covers the Great Speccy Yay :D
(subbed)
Regarding the Horizons tape: my first speccy was a +3 which didn't come with this tape, so i bought it separately because i liked the programs on side 2.
OMG I am so jealous. One of these has been on my "wish list" for the longest time.
I have to be honest, I was an Amstrad CPC man at at the time, but I enjoyed a lot of Speccy gaming at friends houses. I've ordered a treat for episode two which I think you'll enjoy :)
Great video. I like how you explain things.
Sinclair's tech is full of all sort of bugs then :D
Well this was the 2nd of 8 revisions so the bugs were ironed out, they just made sure they used up all supplies first!
I remember destroying a Spectrum by plugging in an Atari Disk Drive Power adapter - little did I know as a kid that voltage and plug shape were not the only parameters to be aware of - the Atari PSU was AC output, not DC. According to the repair company that diagnosed it, every chip on the board was fried! :-)
Ouch. That's the stuff I was always paranoid of as a kid. Guess the paranoia paid off since I've never destroyed anything that way.
Supposedly SNES consoles are also vulnerable to this foolishness because the US and Japanese versions use the same plug and voltage, but the US console runs off AC and the Japanese one off DC.
Quite why anyone was insane enough to make that change when the hardware internals of those two models are otherwise identical, I'll never know.
When I was 11 I destroyed an Atari 600XL by plugging a C64 power supply into it (destroyed the C64 power supply too.. A little while later I tried to get the C64 running again using the Atari supply - hacked the connector off the C64 supply and found it had 4 wires connected whilst the Atari supply only had 2. So I bunched them together (so I was joining AC wires and DC wires together!) then connected the joined wires to the Atari supply. I thought I was a genius when it worked...until an hour later when the C64 cut out and never turned on again.
@ KuraIthys
IIRC the Super Famicom actually has a bridge rectifier that means it's tolerant of both ac and dc.
Might well have been intended as a deliberate trap for grey importers.
There are probably modifications in the later issue Spectrums performed as an indirect result of this.
I desyroyed a TV on board a Carnival cruise ship, by using an adapter to European plug and plugged it to 220V and a lot of white smoke came out of it :))) I was used to using my laptop at any voltage :))
Great job. Please keep making videos :)
Lovely video on the ZX Spectrum 💪🎃👍
My favorite computer, and my favorite game - Jet Pac :D Nice man!
What about ant attack?.
And Chucky egg and Manic Miner!
Great video!!
Again a great video, i never had any experience with this system. Because i had a Commodore 64 at the time and it looked and touched very different. I liked the looks of it, but like i said never had the chance to play with one.
My old mum who was a writer and journalist who adopted the early 1970's PC's for a lot of her work had to fork out for a Sinclair ZX80 kit for me so I would leave her machines alone, the ZX80 kit was gnarly as hell to build, overheated a lot and luckily we had a local RS electronics outlet where I was having to replace all sorts of things until the '81 came out and life became a little more flame retarded, I had with my own Spectrums also an Atari 400, a couple of failed MSX's and an Oric Atmos if memory serves me right but none of them could hold a candle up to the Speccy for gameplay and especially the RPGs like the Hobbit and Urban Upstart, Fourth Protocol were just so ahead of the crowd. Some late developed games like NES's Solstice didn't come out on the Speccy but found their way onto the emerging consoles of which the Sega's used the Z80's closest to the Sinclair platform, Atari were hitting a wall with their dead ended 6502 architecture whilst Commodore were making a killing with the same chipset and Alan Sugar kept the last version of the Spectrum alive with the inbuilt tape or disc drives into the +3's which were the best models but sadly the Amiga came along and Alan Sugar lost interest in competing so it all came to an end with the emergence of PC games and higher powered consoles there was no niche for the home machines really. The ZX80 had 1K of ram and was very basic, the 81 was able to have the toasty hot expansion to 16k if memory serves me right and didn't the +3's have 128K memory? Crazy when I am on a machine with 32Gb compared to that once cutting edge 1/16/64/128K ramsets O.o Amstrad PCW machines could run certain ZX Spectrum applications and games but had no graphical capability but could operate text only games.
I think I still have a ZX80 somewhere. I bet if I found it, it would still work.
I upgraded it to the ZX81's ROM with an added switch. The two ROMs were in the machine and which one had is CS/ line hooked to the decoder depended on the switch. I had a 16K memory expansion I built and a printer for it.
In the US, the output for the TV was on channel 3.
On the ZX80 with some fairly clever tricks, you could do dot by dot graphics. The trick was that all the lines of text where filled with just counting bytes and the character to pixels stuff was changed line by line to make it select lines from the graphic image.
I love the Speccy. Just a quick note for people reading along at home. The power supply is a NEGATIVE TIP power supply, NOT A positive tip like most. So if you do find a compatible voltage power supply please check the polarity of power first and either re wire the tip or make a patch lead that reverses the polarity.
Very good tip.
My first computer as a child was a Timex-Sinclair 1000, the 2K USA version of the ZX81. I bought a few Sinclair-specific magazines back then, and learned of the Speccie, which I REALLY wanted, but I've never even seen one in person, as I recall. I might have to buy one someday, if only to see what I was missing.
Wow, Sinclair called that a power supply. I love quirky things like that
Well, so did Atari, and they were known for solid electronics design. The voltage regulators were all on the main boards inside, as with the Speccy.
I enjoyed that very therapeutic ..thx
Haha, there is "C64" printed on the board... I'm more the Commodore-Type, but now i'm interested what there was that days as opponents... Good work!
Thanks very much, great vid.
brilliant videos well done !
I love The brush at 10:30 xD
I remember buying that particular issue of Crash magazine...and I probably still have it lying dormant in a box somewhere!
Very interesting video.
There is nothing wrong with cost cutting measures as long as they are passed on to the consumer. Looking at the rock bottom prices Sinclair was selling their machines I would say it was a great thing. On the opposite spectrum (pun intended) Commodore’s disk drive was essentially a full computer with cpu, memory and rom that communicated over serial with the main computer and sold at a very high price! Thanks for the great content!
I just fixed dry solder joints in my ZX81 power supply.
i bought a spectrum new in 1982 when they first game out, I have to admit that the first tape i loaded on it was the horizons tape.
+Tim Wilcox There's always one :) NostalgiaNerd had an episode on the tapes recently it was fun to learn about them and their contents
But, but "Thru the Wall"! Erm, I'll see myself out...
Excellent!
I liked this video very much, it reminds me the how its made videos
Looks just like mine, I sold it for £300 with a stack of magazines and tapes two weeks before the crash. Picked up two pluses, series 3 and a 6s, and a spare case a couple of years ago, for about £30.
First thing I did was load the Horizons tape to see the features of the ZX Spectrum. Way back in 1983.
I started with a ZX Spectrum 16k and got an upgrade to 48k I eventually got the Amstrad/Sinclair 128K version.
Excellent video! Does the spectrum keyboard work on a sinclair 1000? Looking to replace mine with a better one
Never had speccy back in the day I was a die hard c64 owner. Brought one a few months ago cheap and got to admit alot of great games to play.i did the easy composite mod as u mentioned and did improve the picture alot
The one I had all the cheap fixes u also mentioned. I thought someone else had bodged it at first lol
My power supply was the first casualty of my constant gaming from about 1984 o wards. It produced the familiar blue smoke but the replacement which is think was a ‘proper’ Sinclair one seemed more stable and certainly never got as hot as the first. However I’m sure someone will set me straight on Cost cutting done in that one as well!!!
There's some nice ZX beeper music actually. And 128's AY chip is capable of producing pretty sweet sounds and was popular mod for 48s too.
czcams.com/video/1eW39C1hQgU/video.html if you want examples.
+failing@commenting thank you sir. I intend to make a part 4 about all the subsequent models, add ons, home brew hardware and kickstarters etc... but I'm hoping the Vega+ debacle will conclude so I can include that story. The AY will feature
Awesome video! Hope you do at least a 5 parter on this. :-D
I look loaded Horizons. After all it was the only software it came with and was Sinclair's response to the BBC Micro Welcome Cassette. Using it allowed you to set up your tape deck for loading and saving.
My god, that is MINT!!! Damn it, wish I still looked that good after all this time!!!
Especially when you remember Britain of that time. We were hardly renowned for quality control and the like in the 70s n 80s!!!
I think that this old transformer based power supply is still safer to use than modern cheap switching PSUs.
The cheaper, the worse. And never have PSUs been as cheap as today.
Nice video, I still have one of these that still works... though mine is not so as pristine conditions as this one, mine is held together by selotape :)
In the video you are saying "Join me in part 2"; did you make a part two of this series? I'm mostly interested in what kind of power supply you used instead of the original one as I recently got my clammy hands on three of these lovely little machines, but only one power supply. One of them is actually a ZX Spectrum+
Love the video.. is there a follow up to this video? I can't seem to find it. Love to see more about this. One of my first ever computers as a child :)
Same - just watched and the video implies there will be a follow-up, but I can't find it.
Clicked the Like button before watching, obviously.
I know it's gonna be great.
I think you need a Weller
Mike Speed
A what?
I already have a Metcal. :p
Awesome video, I learned most of my coding on the sweet Spectrum 128+.... I hope you'll once find the Exidy Sorcerer, to which I lost my coding virginity :)
10:20 I heard this is where the name Bug = a problem comes from. In the early days a Bug was discovered between relay contacts and that stopped that computer working... I can imagine them saying "I found a bug in the program," programs where Hard Wired in the old days.
I belive the inductor stepped the volts up to 15 volts for that needed TV composite unit.
This gentleman's dentist approves his spectrum power supply.
In the late 80s I put my zx power supply on a multimeter 14.8v is a normal open circuit voltage.
it's not cost cutting to have an unregulated external brick. The best place for a regulator is inside, close to the rest of the electronics. Since that needs a higher voltage to operate, and there's no point regulating a supply twice, this makes perfect sense.
First Home computer i ever had the pleasure of using in my big brothers house and loved every bit of it played the crap out of it for at least 3-4 years untill i started with C64 but still played and loved the speccy and enjoyed its original great games
sod the c64 it was speccy then amiga
Sod the Speccy, it was C64, then Amiga! (Ah...the good ole's playground arguments...)
This was great
+hedegaard8 thank you! I'm working on the next episode now... revisiting a system you loved as a kid from a technical angle is a real eye opener. Never meet your heroes as they say!
Will be looking forward to that. I repair som spectrums myself and couple of them laying about always waiting for time from my side to fix them.
Never had one. Was a Vic-20 and C64 guy till I got my 520STFM. Would love one now though
Amstrad CPC 464 and then Amiga 500 here, would love to get a CPC again so I can recreate the playground wars fought between C64, Amstrad and Speccy owners
Me too mate. Would love a C64 and an original A500 or 1200 again. I ditched my STFM about 6 months after I bought it.
Such a head-scratcher that this didn't give the Commodore 64 a run for its money in the US market at the time (tongue firmly in cheek).
I saw a couple other dry looking joints in that power supply on the other end of the board.
+Do R/C! Thanks I'll check that out
I noticed the address on the parcel. I know the place well. I'm from Wolves too! 😊
kimoak lol, I know the Penn road. I'm a few miles south of it.
Looks like polarity is reversed. These days the center of the barrelplug is positive and the outside is negative. In the video you see minus 14 Volts (and leads are correctly put in the multimeter). So wenn buying a replacement powersource, watchs if there is a polarity switch or that you can reverse the barrelplug.
I still have my ZX Spectrum, but sadly it no longer works. A company at the time failed to repair it so it's now just a piece of nostalgia.
The modern equivalent is the raspberry pi. So let the speccy test and play with that instead, it'll emulate a lot including the speccy.
Nah, in the end I bought a working one from eBay and put the board inside my old case, after giving it a good clean. I do emulate systems I don't have though.
i used to love playing dizzy games on my 48k speccy
I miss my spectrum and my atari st and amiga 500 . God dam you parents for trading them in 😭😭😭😭😭
I'd love to own one of these
I’d love to see you work on an Intellivision, it's internal power supply is weird. It has both regulated and unregulated rails, melts my brain.
Going on hard experience, methinks you need to be alert about that 7805 regulator. They age ... and the zener diode inside them can fail. I would replace that 7805 with new.
5 million sold, this is why when in the UK at least we think of micro computers when some one mentions Retro Gaming or chip tunes but in the US they think consoles. Good times.
Ferranti! \o/
I remember having a copy of Atic Atac and couldnt understand why it crashed when loading on my 16k model lol.
I am subscribed with alerts and for some reason YT sent me nothing on this video :( Glad I stumbled across it. You might think of setting up a Twitter account to alert on new uploads.
+Andy R thanks for letting me know Andy. This was initially unlisted as it was early access to Patrons. Perhaps when it went public it didn't notify subscribers. I'll check it out
I’ve read elsewhere that people with this problem solved it by unsubscribing, then resubscribing and turning on alerts again. Hope that helps!
My dumpsterdived ZX hates any switchmode supply ;-) it works with it's original one just fine, but resets/freezes regularely with any modern 9V PSU i tried...
Somethin' with the internal ZX voltage regulator geting confused/oscilating from HF ripples from switcher???
And i believe those memory chips are likely factory rejects - damaged in the remaining (unused ) part of memory...
Still got mine. Was a 16k then had it upgraded to 48k. A year later I bought a DKTronics keyboard case. Still in the loft I think.
I nearly bought a Speccy in the 80's but the shop in Huntingdon only had a 16K so I got a C64 instead.
I think the power supply jack has to be center negative? Might be worth making sure about before frying the thing.
+Nukleon it is indeed, reversed polarity on these ones
Ahhh the memories of hitting all the computer shops on the Tottenham court road and typing...
10 PRINT "YOU'RE A WANKER"
20 GOTO 10
RUN
🤭
Wow you have to hand it to clive he sure used a classy design
That Psion 'Horizons' tape. Yes. I was completely baffled by its entire content. WTF were these programs about? I realise now, it wasn't 'Horizons' that was at fault, it was me. I bought the Speccy because all my mates were getting computers but I didn't have much idea about what a computer could, or should, do. I realise now how clever the programs were - demonstrating the Spectrum's crude graphics, showing the power of random (well, pseudo random) number generations, the application of the IF, THEN, ELSE structure (ok, there was no direct ELSE function in Sinclair Basic) - do you remember the 'Life' program on the tape? It might have been dull, but the software concepts weren't. But, I'm glad I was baffled, because that bewilderment served to stimulate my interest in hardware and programming for the next (nearly) 40 years. Thank you Psion for your (unappreciated) efforts. Thank you Sinclair for the computer I still hanker after.
And, even if Horizons was so dull nobody ever took it seriously, at last everybody got the experience of waiting forever through the beeps, squeals and shrieks to be rewarded with "0:1 Tape Loading Error".
Great video! Just a quick question: what desoldering station is that? I need a new one! Still looking for the MT32, as soon as I find it, I'll check the caps, and mail it on. I had a spectrum too, and the mainboard had terrible dry solder joints! My dad (a keen radio ham in his spare time) resoldered every joint, including the PSU, terrible quality control! still it had great games. Strange to think that the average smartphone is unrivalled in comparison to those old home computers, not as much fun though 😉
Here's the station I use: amzn.to/2hzIgOO
The Spectrum quality vs the Acorn Electron are miles apart. I can understand why but boy can they be nasty to work with. Great idea on checking the caps on the MT32 thank you!
Now you know how Grace Hopper felt, m8!