Restoring an Unusual Indian Computer - The DB Spectrum +

[@spui]

I am a child of that era growing up in Mumbai. A couple of my friends had these with which we played various games. Although loading programs with the cassette reel failed often. I really wanted one of these but from what I remember, they cost was about my Dad's monthly salary(and we were far from being the poorest in the neighbourhood). I think it was about 3000-5000 INR. So getting one for myself was out of the question.

[@bombjack1984]

As a middle-aged man interested in computers, I'm happy to watch a middle-aged man clean a computer.

[@fredsmith1970]

And as a middle-aged mad interested in computers, I'm happy to comment about a middle-aged man interested in computers, commenting on a video about a middle-aged man cleaning a computer. :-)

[@himselfe]

This is getting lewd.

[@ShinoSarna]

I'm a young adult woman happy to watch a middle aged man clean a computer, lol

[@ynotwalk7391]

and such a dashing one

[@syrus3k]

I am also this demographic.

[@peterlinddk]

I must say that I appreciate the irony of removing the chips, before putting the board in “the chip fryer” 😀

[@KuntalGhosh]

12:28 yup someone has worked on it , those keltron branded capacitors are made by a state owned company and they are my goto choice for any cheap capacitor needs , they are low cost and good quality never had premature failure on them ..

[@MarcKloos]

When I got my dB Spectrum, it was very dusty, no nasty bugs and a bit smelly! It came boxed and all and was almost working -- one lower RAM chip was busted. I simply replaced my rubber legs with new ones. The membrane was working fine, it looked as sturdy as the Samsung ones. As you can see, there are 2 variations of this "Issue 7A" - mine has a 32k daughterboard, while I've seen 2 other dB's (at one time I had 3 in my home - 2 for my Speccy collecting mates) had only 2 upper ram chips, similar to the Spanish Inves Spectrum+.

[@MarcKloos]

I also have a photo of an Issue 7C -- here the lower RAM consists of only two 4164 chips.

[@bennyturbo]

Small tip when using ultrasonic cleaner to ease up on the cleanup. put your screws or parts you want to clean in a sealable bag with the rust remover in it, and then fill the ultrasonic cleaner with water and put bag in water. Cleanup is as easy as emptying the water and using kitchen towels.

[@cheater00]

Hi Neil! Instead of using super glue, use plastic welding compound (based on MEK - Methyl Ethyl Ketone - and other chemicals) which will give the plastic a MUCH better bond, like it's a single part again, and it will strengthen the plastic around the break too.

[@borayurt66]

Pure acetone works very well too.

[@cheater00]

@@borayurt66 no, that damages the plastic too much. you want a dedicated plastic welding compound.

[@borayurt66]

@@cheater00 You are right. It should be used very carefully and sparingly, in tiny amounts. But when you get the hang of it, it really works brilliantly especially for small parts like this. Creates almost seamless bonds. I apply it with a needle to both parts, then combine them. Acetone evaporates very quickly and what is left is a one piece plastic again. A dedicated product will be more forgiving for sure, I can't deny that but this also works. Needs practice though.

[@cheater00]

@@borayurt66 i've repaired parts that are less than 0.5mm across using welding compound, using the same technique you say. and the bonds were fully - not almost - seamless.

[@borayurt66]

@@cheater00 Yes, I just looked it up, it is commonly called Butanone. I will get some and try it. Thanks for the info!

[@NeonEUC]

Once again.. perfect timing. Literally just bought beers hoping you would have a video up for later... and here we are, YOU LEGEND

[@RMCRetro]

Save me a cold one please

[@mrr2816]

Lol touché!

[@NeonEUC]

@@RMCRetro one for you and mark waiting 🤘😎👍

[@fensoxx]

Thank you so much for this video. I’m happy you made a retro computer museum but these are the videos I subscribed long ago for and always wish for.

[@gower1973]

That second regulator is most likely to power peripherals connected to the user port, like a couple of people have said in the comments its a 7809 which would be a 9v regulator, I think the Commodore64 also has 9v on a user port pin.

[@Zeem4]

The ZX Spectrum supplies 5 and 12V on its expansion connector, so it's not for that. The Commodore 64 has 9 VAC on its user port, supplied directly from the power input to the computer.

[@kenknight5983]

Suddenly I'm wondering what the Indian games scene was like in the eighties and nineties. Home micros means people were programming- there must at least be some stuff made in BASIC.

[@belstar1128]

I doubt there was much back then computers where more of a luxury item in developing countries so this thing was probably used in a factory or office i have never been to india but i have been to other developing countries in the late 90s and even in the 2000s i did not see any computers or video games i took a game boy with me the locals had no idea what it was i assume it was similar in India and this thing is from the late 80s so computers where even less common at that time.

[@hjalfi]

India almost shared a border with the Soviet Union, and (looks it up on Wikipedia) had a treaty with them. Spectrum clones were huge in the USSR and they kept making and using them long after the rest of the world had abandoned them (hugely upgraded). That's a whole rabbit hole to delve into. I wonder if this had much influence on India's use of the Spectrum.

[@KuntalGhosh]

games were non existent , computers were mainly used for work and office , it was a novelty item not only the price was an issue back then india had stupid restrictions on import and everything required a license , 70s 80s was the worst as government was almost communist like and my state had communist government till 2010s from 1970 , they were totally against use of computers as it would replace hundreds of jobs. , thankfully the 90s saw a lot of change , my dad started his teenage days by making battery backed up tubelights , moved to repairing tvs and fridges in his 20s and then started a cable tv company , in 1996 he bought his first pc , a 150mhz Pentium .. now days the scene is different as computers got super cheap in the 2000s , internet spread like wild fire . computer gaming was popular among 2000s kids like those who were born in the 90s had access to computers and games ..

[@MajL337]

@@belstar1128 I'm Indian and I had a computer in the 90s. However I know nothing about the 80s computer scene here so this videos is interesting.

[@IndianVideoGameCollector]

Well, we did have an official NES launch called Samurai here in India in the late 80s, I have done a couple of videos on that coverage, do check them out if you are interested. @RMC: this is good stuff, I wasn't aware about db spectrum+ , I will check on this

[@MarkFixesStuff]

When you said "quality imported filth", I immediately thought, "I'll get the blame for that...".

[@smayds]

Strangely enough, when I heard that line, I thought "Mark's writing scripts now?!" True story.

[@TechMadeEasyUK]

Licensing of Western computer designs was quite common in India all the way through to the early 2000s. I found my own example a couple of years ago: an HP Pentium Pro machine branded HCL, for Hindustan Computer Limited. At the time it was difficult for outside companies to trade in India due to beurocratic processes designed to give domestic companies an advantage. These days less common of course

[@KuntalGhosh]

yes hcl , all of the computers in my school was hcl branded.

[@handlesarefeckinstupid]

It runs to a lot of other items as well. Cars, rifles etc.

[@jensdpunkt3705]

Well, when I saw that little Speccy coming alive I was...happy! A Spectrum was my first computer back in the day (hard to get in Germany, but I managed somehow), and still I remember it fondly. It made me the IT Pro I am today and it opened the whole world for me. Thank you Sir Clive and thank you, trusty little Spectrum.

[@seraphinberktold7087]

English summary below... Ich würde nicht sagen, dass es schwer war, einen ZX Spectrum in Deutschland zu bekommen. Meinen habe ich einfach bestellt. Nein, nicht online, sondern per Telefonanruf. 😉 Es gabe einige Spectrums in meinem Umfeld, wenngleich C64 und später die CPCs weiter verbreitet waren. English: ZX Spectrum computers were easy to order in Germany. I had some Speccys in my vicinity but C64 and later CPCs were more common.

[@Bukkarooo]

Absolutely lovely to see it restored and cleaned up so much. Like a lot of other commenters, now I'm curious what the home computer and software scene was like in 80s India! Something I never thought about before. Considering the history (and this computer), I imagine they probably had a good few similar micros to the UK in that time.

[@peteshilling6873]

Watching this was the perfect break between building desks for my new retro gaming room. Sadly running out of room had stopped me buying any more consoles and computers but not now.. Hugely excited as a middle-aged man can get .. Love your videos btw. Please keep them coming

[@Potts1966]

very nice.. I love how these old machines really want to live and are (usually) pretty easy to fix.

[@RidgeRacer]

Super interesting to see the cleaning process for a machine like this one here. Seeing the mainboard come out of its PCB cleaner and distilled water bath really took me aback, wow was it effective. So cool. I think I might need to get one or ten of those ultrasonic cleaners..

[@retroretiree2086]

A dishwasher is as good for motherboards and yes you do have to wash it off afterwards with distilled water :)

[@thepenultimateninja5797]

A little tip for restoring rusty screws; throw them in a pan of water (distilled if you have it, but tap water is usually fine) and boil them for about half an hour or so. This will convert the red rust to a black iron oxide, which is likely the same finish that they had when they left the factory. They will look brand new. It's like magic the first time you see the transformation happen..

[@thepenultimateninja5797]

@@blackterminal Vinegar will just dissolve the rust. It will leave a black smut on the surface, but that's not the same thing. Rust killers or converters vary, but none of them has the same effect as boiling. Converting red rust to black iron oxide by boiling has been used for centuries as a firearm finish - it's called 'rust bluing'. This involves using a solution to deliberately rust the steel, and then boiling the rusted part to blacken it. There are several videos of the process on youtube. Boiling rusty screws basically works in the same way, though it is much less labor intensive than proper rust bluing.

[@choi13a]

I don’t need PCBs or a website but I really appreciate sponsors like PCBway, Squarespace, etc. for funding all this wonderful retro tech content from RMC, Retro Recipes, Nostalgia Nerd and many others.

[@choi13a]

This comment was not sponsored.

[@JohnJones-oy3md]

Amazing that this was still manufactured in 1991 (or later), considering the 1982 on-screen copyright.

[@Jef_Vermassen]

The retro wash is highly therapeutic, can't wait for some retrobrighting again. While I absolutely loved building the cave series. It's also fun to see some of the more regular things coming back. :D All the best with running the cave, hope I'll pop over some day. :)

[@hardcore8uk]

Excellent Neil, did not know there were exact Speccy+ copies sold in India, i love all things Sinclair as the Plus was my first PC back in 1985, was watching "Modern Vintage Gamer" the other week showing off a Timex TS2068, what a lovely version of Speccy that was , with AY sound , ROM Cartridge, twin 9pin joystick ports, could even have the Sinclair rom swapped over to make it nearly 100% Speccy compatible minus the AY Sound support, quality, I would have loved one of them as a 14 year old back in the day!!!!!

[@ScottDuensing]

I seriously wish I had your patience and skill for my own collection. Thank you for preserving these machines!

[@schneil]

In New Dehli, October 1993 - I saw the a zx spectrum being used to type messages on a local cable TV channel. The font and "L" cursor were a big giveaway.

[@TheErador]

Yas, weird hardware from the 80s my fave.

[@gdutfulkbhh7537]

Bravo! Nice restoration.

[@ncc17701a]

Ahh - the old membrane keyboard. I had a part time job after school repairing computers, and I remember having to replace these quite often. I also remember getting in a Spectrum where someone had plugged in a power supply (wrong one) into one of the jacks. The ULA rather spectacularly blew a hole in itself and the circuit board. Still managed to repair it and get it working again, but it looked like a cat's cradle with all the wire patches I had to put in. Fun days.....

[@safirahmed]

It's possible the second voltage regulator could be to regulate voltage in the event of variable voltages from the mains to protect the computer from load shedding where power is reduced in some areas.

[@JohnSmith-xq1pz]

Perfect timing got me some pizza pops, barks root beer and a RMC video

[@RMCRetro]

I'll take one of everything please

[@JohnSmith-xq1pz]

@@RMCRetro For you Neil it's on the house 🤣🤣

[@piconano]

I've never seen one. Thanks for showing the guts and the great restoration.

[@RMCRetro]

Thank you for watching it and for the tips in your other comment

[@ClassicRetroByte]

You did a fantastic job on cleaning that old dirty machine well done you and a fantastic bit of of Spectrum history 👍that is now working again, Thanks to you

[@neilgoward5632]

Couple of questions Neil. 1. Did you keep the original membrain label for posterity? 2. Did you dump and compare the ROM was it completely standard?

[@borayurt66]

It is most probably exactly the same. Although there were some known bugs on the original firmware which can be corrected, there are some third party hardware and software which does a quick ROM checksum and if even one byte is different, the checksum would fail, causing the said item refusing to work. The bugs I mentioned are not significant for a regular user, but they can become an issue for programmers, and when they did, people invented ways to circumvent these bugs. This also makes a "corrected" ROM to fail with these programs. It is not the best idea to use a modified ROM image in Spectrum machines because you can get incompatibilities. I noticed the ROM IC is a standard 27C256 EPROM, which is not totally pin compatible with the original 23128 used in the UK machines. The difference being (I think?) just 2 pins needs to be swapped. So I am guessing that part of the PCB design is also different along with the 2nd regulator.

[@manoliskypraios8153]

Memories ..... so many memories !!! Great Job!

[@mymidschoollife8485]

I bet we all said "Mumbai me a Spectrum" when we were kids.

[@ajinkyamahajan102]

I didn’t knew there were 8 bit computers in India back then. Almost I thought the 2000s boom with 32 bit pentium machines

[@liveuk]

British under licence

[@StuffWePlay]

Wow this is a beautiful obscure machine

[@BobsBand]

This is almost as heart-warming as those animal rescue videos I can't help but watch on KZbin.

[@davesmith1044]

I came across one of these at a flea market in the US state of Oregon in the late 90s, at the time I didn't know much about micros or foreign computers so passed on it, wish now I hadn't. The stall did have a C64 which I did buy, my first in-fact.

[@MarcKloos]

Was it this Indian dB Spectrum or a Sinclair ZX Spectrum? I do know of a guy in Portland, OR who took it with him when he moved from India to the US, but he's still clinging on to it (I tried to buy it from him years ago!).

[@davesmith1044]

@@MarcKloos it was the db, I remember it clearly even though it was so long ago, as it was where I bought my first c64. It was in Salem, if you know the area at all it was on southern lanecaster dr. Used to be a rather large flea market l, I think it’s a movie theater now. Was a stall there that always has micros and other odd (to an American youth) pcs.

[@1969ashley1969]

I had a ZX Spectrum 48k back in the early 80's. I remember the Horace games, I certainly remember Horace goes skiing. Oh the memories. :-)

[@piconano]

you should keep toothpicks and q-tips handy. use the toothpicks when you apply glue or oil in small spots, then throw it away. With a drill bit, I had to clean the bit after. The q-tips and EPA is critical in cleaning small stuff or tight spots.

[@hjalfi]

We totally need an official RMC playlist of Music To Clean Your Keyboard To.

[@RMCRetro]

I will make this happen, great idea, and not even ironically :D

[@hjalfi]

@@RMCRetro Fantastic!

[@BarrowZigger]

Top work! Love these vids.

[@Jenny_Digital]

With regards to the break key, I’d be inclined also to wire whip and glue round the outside of the post if there’s room. Just because I’d imagine the forces on it being a bit much for the glue-able contact area otherwise.

[@Jenny_Digital]

@@blackterminal why but of course it will, but we want the only the best for that which we value. No sense going half in. Incidentally, I spent around three days carefully stripping, cleaning and reassembling a whole bunch of keyswitches for the Acorn Electron I grew up with, and not because of its awesome computing power, rather more that it was my _first_ computer.

[@biscuitsalive]

Great vid. Satisfying and well put together.

[@jengelenm]

Cool. Nice ultrasonic bath machine. Always handy, even a bigger one!

[@moonbladem]

I love watching Greg Salazar clean dirty PCs and gaming consoles, so I guess KZbin's algorithm thought I'd like your channel too. It wasn't wrong! :) I love your ultrasonic cleaner!

[@nomadic_shadow]

I really enjoy seeing these exotic machines being restored.

[@badvoiceallnoise]

im 21 and still enjoying watching retro tech stuff

[@gibbonduder182]

Plessey were a subdivision of GEC, some of their factories were in the Midlands.

[@Rockythefishman]

Nice, another one saved for the future

[@Turnbull50]

Such a brilliant and very enjoyable video thanks

[@RetroJay1974]

Brilliant! 20+ minutes of pure bliss. I love all these wacky and weird Spectrums. I sadly never took any notice of these things back in the day, now I am interested I have no idea where to obtain one :(

[@them8434]

kor-man! That looks great but even though people tried to tempt to get a spectrum , I was having naan of it!

[@RMCRetro]

get out

[@hardcore8uk]

@@RMCRetro Totally Neil, I'm sure the C64 door is the first door on the left !!!!

[@oldskoolpaul77]

Great video! I loved the cleaning part! 😃

[@subliminalvcr]

Superb video and really good to see you cleaning computers again - must get myself an ultrasonic cleaner! Your content is just so well done and really does relax me, especially after a difficult day. Looking forward to visiting the museum soon. 👍

[@williampmcd8548]

white vinegar is an excellent rust treatment too. saturate a paper towel, rap the rusty item in it over night. great results

[@Alex-jb5tb]

Very interesting video. Didn't know that `my` beloved ZX Spectrum made it to India.

[@milk-it]

Top video. I really like your restoration videos. Please produce more!

[@retrorelicsandrepairs8572]

It would seem I’m not the only one amused by “finger bovril” 😂

[@charlesjmouse]

Interesting and well presented as always, thank you. There's no slime like human slime, eh? Also interesting, at least to me, that that PCB looks like it was manufactured with a (somewhat) modern process. No lumpy floods there. I wonder why the extra regulator and type? Guesses running from designer's preference to increased RAM options or smoothing bad power.

[@ashy001]

Some of us do our “middle age cleaning” in private. 🤣 Watching your videos made me finally by a Amiga 500 again like when I was a kid. I also pulled it apart land cleaned everything then recapped it and then modded it.

[@RMCRetro]

Another A500 saved! Nice job

[@peterwentworth9181]

I do like all you do on this channel, but l love the retro repairs the best👍

[@adambourne5523]

Always ready for a chill cleaning montage

[@jaytee200]

7:13 I’ve not heard that phrase since the man who owned the video rental store gave me a tape from under the counter 😄

Nice. Be careful filling up the ultrasonic cleaner tank to the minimum recommended liquid level, otherwise you may damage your cleaner. Your motherboard cleaning session seemed to have insufficient liquid. Thanks.

[@RMCRetro]

Thank you I'll keep that in mind

[@Ingens_Scherz]

@@RMCRetro 😂That told you!

[@delos86]

Why is that? Would you mind elaborate it a little bit further or provide some legit link please? Cheers

[@paulturner5769]

@@delos86 Too little liquid results in low pressure at the transducer which can lead to cavitation damage.

[@jinxterx]

@@RMCRetro and fix the wobbly table plz! :P

[@guillepankeke2844]

Same with the CZ Spectrum here in Argentina, and another of some other name in Brasil.

[@rmcdudmk212]

Another cool spectrum and another great restoration. Keep up the excellent work RMC.

[@10p6]

If you take all revisions of the Spectrum, and all the clones, it probably sold much more than the C64.

[@johnknight9150]

I genuinely LOL'd at "finger bovril", kudos.

[@PaulinesPastimes]

Mmmm, cleaning. Those key caps seem to be never ending but the result is so worth it. Another very interesting machine for the Cave.

[@tmaxyb]

Love the show, love the music, sounds like something from the seventies .

[@TanjoGalbi]

I do see the desire to keep the machine as original as possible, especially as it's only going to be on display and rarely used, but if it was to be used often I would replace the voltage regulator with a modern compatible one that does not need the heat sink. They are more reliable and future proof. Also, no mention of repairing the reset button! Did you reconnect the wires to it? 😏

[@EsotericArctos]

The only trouble is, those sort of modern regulators are generally not linear and use some kind of switching to reduce the voltage with less heat. These tend to introduce switching noise, which is not accounted for in the Spectrum design. This would cause degraded operation due to the switching noise being introduced to the power lines on the board as there is not filtering to counter it.

[@alynicholls3230]

oh man@@EsotericArctos you are so correct!, i see switch mode supplies and regulators being used all the time its almost a snobbery against linear, but there really is no need linear is what it was designed to use, if the supply is bad rebuild it replace 7805's with quality replacements your speccy will run better.

[@brendonelton]

You soldered that voltage regulator like a boss Neil! Who needs Mark....! 🤣

[@gregbeliveau4773]

Finger Bovril 😂😂😂. From one middle aged man who enjoys cleaning things, cheers from north west Texas.

[@GodmanchesterGoblin]

So what does the extra regulator do...? I thought you might just have used your meter to figure out what it was connected to. I was also intrigued by that EPROM (32k bytes instead of the usual 16ķ).

[@licensetodrive9930]

I had a ZX Spectrum+, the design of the keyboard keys left a lot to be desired, they needed to be tapered like the keys on their +2 & +3, you could not type fast at all as the keys would rub against each other.

[@amigachris]

Style over function, the early version keys fell out when turned upside down 😅

[@dav1dbone]

Not watched complete video yet, interally derived voltages are worth checking, im guessing the other regulator is aditional to this circuit, good idea too. I'm wondering if there's a custom rom for the Indian market?

[@JenniferinIllinois]

It's not working, it's filthy and it's unusual. Yep, that's why I'm here. Hehehe...

[@TheDarkHour684]

Saw some tandoori chicken remnants in that case. Bit of naan.

[@markwanklyn4195]

spotted the EPROM is a 27256 which would be 32K - different contents to the normal Spectrum 16K ROM or just the 16K ROM in both upper and lower? Also is the 'db Spectrum+' label covering up the original Sinclair markings, have they been machined off or is this a different case moulding to a standard + machine? That 2nd voltage regulator is odd, is it a 7805 and if it is were they trying to spread the load across two regulators to extend the life?

[@RMCRetro]

There is nothing under the label, and the plastics feel a little rougher than a regular Speccy so I think the cases must be manufactured in India or at least elsewhere to the normal place. The 2nd reg is a 7809

[@markwanklyn4195]

@@RMCRetro--5v volts for the 4116 RAM chips? might be worth dumping the EPROM to see what is on it - correction 7809 would be 9v not -5v so not that

[@Zeem4]

@@markwanklyn4195 My semi-educated guess is that the 9V regulator is supplying the collector of TR7, which drives the loudspeaker.

[@MarkFixesStuff]

The ROM is bog standard. Not sure if it's packed in twice but I'd bet it is. The second reg is a 7809 and I don't know what it's doing as yet. There is a 7805 as usual as well.

[@DarkAvatar1313]

I'm surprised you didn't re-cap it, but still a bang up job.

[@voffie]

Very satisfying, well done. What a beauty!

[@andydavidson1278]

A thoroughly enjoyable video to watch👍 This is not something I’ll ever be doing myself, but it was really interesting.

[@paulb4uk]

Superb not a machine I knew existed .I do have a rubber key 48k that has a made in Portugal label as far as I know it is the same as UK models but it does need repair.

[@10p6]

Nice to see 40 year old ish tech live on.

[@burnrubber7547]

Load " " - enter. Volume set to 7.5 on the tape player. Will the game load? Ah nostalgia. The patience we had : )

[@GeVeBeGaming]

Always find your content so entertaining.

[@RetroCCTech]

Out of curiosity, what is the model of fryer/sonic cleaner you are using?! I have a few pcbs of spekky size to clean up, and that one looks to have decent dimensions.

[@frankowalker4662]

Cool. Exelent clean up job. I just assumed other countries would have imported the UK Speccy with RF mods.

[@belstar1128]

India had very strict importing rules and taxes back then.

[@Dorff_Meister]

Nice work!

[@porkybitz]

"It's not working, it's filthy and it's unusual"

[@marcsmith3782]

Is that a JY-2 Joystick I spot being used at the end?

[@RMCRetro]

It is yes

[@standroid2406]

the keycap repair is impressive! you must have the hands of a neurosurgeon!

[@captaincorleone7088]

@18:59 Which game is that? If anyone knows, please tell me as I'd like to check it out. 🙂

[@RMCRetro]

That's auf wiedersehen monty

[@captaincorleone7088]

@@RMCRetro Thanks for replying! I'm going to download the .tzx image for my Speccy. 😁

[@SelfIndulgentGamer]

I got my Membrane from ZX Renew too, a great replacement :)

[@zach123101]

Yeah I don't know why I never thought of retro computers in India

[@franciscomeza8905]

Awesome restoration RMC, although it could use new capacitors as those in the machine look dicey, Cheers.

[@acerIOstream]

My guess re: second voltage regulator is that India and other similar parts of the world used to have very "dirty" power, i.e. the voltage and current would fluctuate wildly since the infrastructure just wasn't quite there yet. The second regulator might have been to help even out those fluctuations even more in those regions and keep the micro running smoothly. Wild guess though.

[@Djformula]

Spectrum Zindabad!