Sinclair QL Microdrives and Microdrive Repair (Part 3)

[@daholmes1]

My Dad was the designer of the microswitch used in the microdrive, he was engineering director at Burgess microswitch. The same switch was used on the sinclair C5. I remember as a child him bringing blank Microdrive cartridges home to show me, including a clear one, before the drive was launched. I am sure he told me that the name they were planning on giving the cartridges was a ‘skipsel’’ but never heard that used after launch.

[@NoelsRetroLab]

Oh wow, very cool! Did he/you use a QL at home as well?

[@daholmes1]

@@NoelsRetroLab oh yes, very much so, still got it now. Did my entire degree on it in 1988 and continued to use it as a daily driver for a number of years afterwards.

[@donaldklopper]

I loved my Spectrum's Microdrive, but I only had 1 working cartridge. Yes, 1. I had no money to buy more. I had another one that I received as a gift, but which was unreliable. My first cartridge never gave me issues over a couple of years' use. I remember these cartridges costing R15 in South Africa in 1985, which translated to around a full day's wages for a schoolboy job at a computer shop way back then. I loved the fact that I could random access my files, and I had my fave game on the cartridge (Manic Miner of course) plus a bunch of my personal programs, amongst others my alarm clock program that played back a small voice recording as an alarm notification. Yeah since there was no real-time clock I had a timer loop that worked well enough. I woke up to this for months until the Microdrive interface overheated and I was back on cassette tapes. What a time to be alive!

[@NoelsRetroLab]

The random access feels almost magical when you think it's a tape media! 😃

[@h.cavidarabac3852]

It is faster, cheaper, smaller and it is much more silent. Disk drives has more layers that can insulate sound, microdrive is just covered with the plastic case. The noise felt like there is much less struggle going on and that made it feel snappier and much more modern. Just brilliant! Much respect for mr Sinclair and his engineers

[@stephenlittle7534]

Hi. Love this as I was a QL. User. Back in the day's 😃😃😃😃. One thing we did learn early was when you started looking at the software you first copied all the drives so you had two to four copies of each software. To use as every day use. The originals were keep safe in their pack and only touched if you had no copy drives left working. Because they would layer fail you down the road. Good old days.

[@NoelsRetroLab]

Right. I saw that even in the QL Users Manual. So they knew that the microdrive cartridges wouldn't hold up to a lot of use. But then again, even Amstrad recommended making copies of the CP/M disks the computer came with, so maybe that was pretty standard advice.

[@seraphinberktold7087]

​@@NoelsRetroLab I read that early Microdrive cartridges had a plastic spindle. That made them less reliable than those with a metal spindle. Damn cost cutters! 😅

[@GadgetUK164]

Very cool! Despite owning a Microdrive when I was a kid, I had no idea it was a continuous tape! Loading times were great, and 100K was fine for the Speccy.

[@NoelsRetroLab]

That's true. For the Speccy was more than enough. It gets tighter for the QL and saving graphics and long text documents, but still. Cartridges were cheap, if only they had been reliable!

[@GadgetUK164]

@@NoelsRetroLab Still a really nice piece of history there! Jealous of that QL =D

[@jacquesmertens3369]

Failing QL microdrives were the beginning of the end for Sinclair. They gave the entire machine a bad reputation. Sinclair did fix the issue shortly after the QL launch, but it was too late. Too many machines with faulty drives had already been sold and trust in Sinclair was lost.

[@NoelsRetroLab]

Right. Which might have been salvageable for a games machine, but not for a serious business machine.

[@wesleyjesiah4772]

instaBlaster

[@tarstarkusz]

Do these things have a 2nd track? It seems to me you would need a 2nd track as a control track. Otherwise, you would have to read in the control information when you first insert the disk and then keep in memory otherwise. That seems really stupid.

[@jacquesmertens3369]

@@tarstarkusz I'm not even sure there is any control information other than at the start of each sector, and no control track either. The cartridges (not disks) contain an endless tape loop. The machine reads the contents by going through the entire loop and loading the relevant information about each sector into the memory. The tape does contain 2 tracks, but both tracks are used alternatively for storing data. Byte 1 on track 1, byte 2 on track 2, byte 3 on track 1, etc. Sinclair already had bad experiences with the ZX microdrives, especially with stretching of the tapes which made data unreadable, but to save money they decided to use them in the QL anyway, but at a lower speed and with a soft start/stop to reduce wear and tear. Yes, even slower than the ZX. Clive Sinclair had a reputation for cutting corners to save a few pennies and usually got away with it. But not this time. Regardless of the technical issues with the microdrives the biggest mistake was to try and market the QL as a business machine, which it never was.

[@geekyprojects1353]

I think your channel is underrated (or very new). I liked the video and the explanations. Thumbs up!

[@NoelsRetroLab]

Thank you! I've only been doing this for about a year, but I'm having a blast with it 😃👍

[@jeffm2787]

Good to see someone using an oscilloscope for actual diagnostics. Got the tools, use them. I'm down to three scopes and about 20 or so meters.

[@randyab9go188]

People keep giving me scopes! I have 8 or 9. I have given one to a deserving student. I have a analog meter fetish. I have several Simpson 260's and three Tripletts. I feel your pain!!!!!

[@jeffm2787]

@@randyab9go188 Analog meters, I have a Fluke 803B.

[@GORF_EMPIRE]

A most excellent video. I remember when the QL came out and I was definitely looking to get one. I almost wish I did. But I went with the Atari ST line and have no regrets.

[@luisluiscunha]

In what concerns the QL, your little helper has more luck than I ever had: never used a real QL although I see videos like these before sleep :)

[@8BitRetroJournal]

One more note...you proved Sinclair's ad campaign with regard to speed of the microdrives as that is the argument they made (i.e. that throughput was better than disks due to their seek times). Still, I'm glad I use the vDrive, as failed microdrive cartridges causing endless spinning can be frustrating. I think they could have fixed the firmware to stop trying after a few loops and just give you the option to get a corrupted file. On many occasions, when I do a sector recover, it's a few bytes in one sector that causes that.

[@NoelsRetroLab]

Yes, the endless spinning seems like horrible design! Maybe Minerva fixes that? vDrive is on its way. Can't wait to play with it!

[@8BitRetroJournal]

@@NoelsRetroLab note that I love my vDrive but be warned that it emulates the microdrives (I think, fooling the QL timing-wise to think they are real ) which means that the speed is not what one expects from SD car readers. Marcel Kligus is coming up with a ROM cartridge SD card that I think will act more like a hard drive device (WIN device) so should be fast.

[@EmmittBrownBTTF1]

Microdrives write to the first "available" sectors that pass the read/write head; and load any sector that passes the read/write head if it is from the requested file. At least according to the interface I rom code. Formatted for Spectrum, sectors held 512 bytes, QL format 1024bytes. The tape is the same quality as video tape. Some of the cartridges I had in spectrum format were managing 118k, so 236 good sectors. One did 124k, or 248 sectors. Sinclair recommend first time cartridges be formatted 3-6 times, before use, to stretch the tape substrate

[@bobbus_74]

Never owned a QL but I did have a Spectrum with a ZX interface 1 with two microdrives. I loved the fast loading compared to standard tapes. Well it seemed a lot faster at the time.

[@NoelsRetroLab]

Oh yes, so much faster!!!!

[@RetrogradeScene]

Great video! Nice to see such a close look at a rarer format.

[@paddycoleman1472]

Great video. I had ZX Microdrives on my Spectrum in the 1980s. At the time, they were quite competitive especially when Sinclair reduced the price to £1.99. I never had any data loss/reliability issues with my Microdrives. Like a lot of things, the Microdrives were delicate, precision devices so I suspect many issues were caused by the user.

[@NoelsRetroLab]

That's very likely. Especially since you could pull them out in the middle of an operation and I suspect that'd be the end of them.

[@rog2224]

@Paddy, I don't know if this is a real memory or not, but didn't W H Smiths have their own label ones? I remember both them, and Boots the Chemists having a lot of own label blank media

[@BertGrink]

@@rog2224 It wouldn't surprise me if both W.H.Smith and Boots had their own branded microdrive cartridges; i know for a fact that at least Boots had their own line of 3" Compact Floppy Diskettes, the kind used by Amstrad and the Spectrum +3, but the Boots brand is rumoured to be of very low quality. If the same sort of low quality also applied to their (assumed) microdrive carts, then it's no wonder that the medium would get a bad reputation.

[@BertGrink]

@@NoelsRetroLab I suspect that if one tried to remove a cartridge while the tape was running, one would end up with what we in Denmark call "tape salad" and that is not nearly as delicious as it sounds - trust me!

[@paddycoleman1472]

@@rog2224 Hi Roger, Not sure, does not ring a bell. I actually bought my Microdrive from John Menzies though - the £99 pack that Sinclair released with Interface 1, Drive and Software. I was fortunate as I was working for an an independent computer shop not long after so had access to Microdrive cartridges and Amstrad disks at very low prices i.e. zero. It was a perk of the job - nothing illegal. :-)

[@Exacerbate42]

I had a Microdrive and several cartridges for the "ZX Spectrum 48k". Together with the "Nordic Power" module, I was able to completely save every game at the score I was on to a cartridge within a minute, and then import it back into the ZX Spectrum. That was unique for the time.

[@user-vs7cw2rg7r]

I've been wondering lately, what if all of the effort sinclair put into the spectrum+, 128+ and ql, what if they had just put out a 128+ with the interface 1 and interface 2 and twin micro drives built in. With the ql keyboard (which really wasn't at all bad) and maybe the expansion bus too. That would have been quite a machine. Still, loved the video series. I was a spectrum 48 user as a kid and a big sinclair fan. The QL always intrigued me. I finally got to see one for real at the Cambridge computer museum this summer. Well worth a visit.

[@edgeeffect]

I remember being intrigued by how good or bad microdrives would be when they announced them for the Spectrum.... looking forward to finally getting a look.

[@NoelsRetroLab]

Apart from reliability issues, they were a lot better than I was expecting. It's kind of magical how they offer random access (ignoring the up to 7 second seek time).

[@PrivateSi]

I wanted them to bring out the Spectrum QL with a Z80 coprocessor instead of the barely upgraded speccy and late + rushed QL.. No built in microdirives but matching double microdrive, disk or cassette bolt on available separately... More memory or at least more allocatable to graphics modes (more colours, higher resolutions)... Dual CPU systems were not that rare back then and Sinclair developed their own systems so could have... Crashed two markets instead because they rested on their laurels and milked the Speccy for too long and then didn't upgrade well while trying to milk their market presence by bringing out a separate business machine, The QL, which they launched late, buggy and under-developed... Killed their entire business, not brining out The Sinclair Spectrum QL.... Developers would have loved my version.... as a ZX81, then Speccy, then QL User...

[@101blog]

I must say I was very happy when I got my Medic board and had Floppy disks... Still have tons of Microdrive tapes I should get them out and amaze my self 26 years Latter!

[@lostcarpark]

Love these videos. I had a QL back in the 80s. I lent it to a friend, and never saw it again, unfortunately. Would love more QL content.

[@MrNoobed]

I love micro drives just because the form factor/design is so nice.

[@MindFlareRetro]

Another great video (A+ for content and presentation, as usual) and a great series. These Microdrives are fascinating. Sadly, I have never been in the same room as QL, but this series was an excellent look at this system. As always, keep up the great work.

[@NoelsRetroLab]

Thank you so much! I had never been in the same room as a QL before, and now I'm really enjoying this system. I'll definitely keep coming back to it!

[@jaysinha0]

I have fond memories of my QL. The microdrives were quite reliable and fast (compared to cassettes!) except when the locking spring on the right hand side of the drive began to weaken and wouldn't push the cartridge against the motor. The £4.99 cost per cartridge was outrageous - £1.99 was more acceptable.

[@HAGSLAB]

Great video Noel! :) Those microdrives look pretty unreliable but really cool!

[@NoelsRetroLab]

Thanks! Yes, my thoughts exactly. Amazing for the time though!

[@ElectronGordo]

Thanks Noel for this video, that helps me for repair my QL. One tip, better to put the glue on the foam pad, not in the cartridge, that way the risk to spelt some glue into the cartridge almost disappear.

[@NoelsRetroLab]

Great tip! You're right. Thanks!

[@8BitRetroJournal]

I was able to replace a ULA on one of mine by just removing the motor (two screws) and a solder sucker and some patience. You can get at most of the pins except the the final two . I also covered the plastic post with aluminum foil to protect it from brushing the soldering iron. To get the last two I pulled the chip from the other side as I heated the joins (with a small solder tip), making sure to avoid melting the post (foil helped here).

[@NoelsRetroLab]

Interesting! I didn't even consider that option, but that might have been easier. Although I was afraid that the read head would be tricky but ended up being 6 very solid pins, so that was fine too.

[@preferredimage]

Also put some pin headers on the ribbon ends, makes plugging and unplugging much easier and connections more robust.

[@MoosesValley]

A friend of mine had a ZX Spectrum with a microdrive, and I was still using my Apple ][ with cassette tapes at the time, and they sure seemed to work well. Very cool to be able to get a catalog of what is stored on the tape, and just load a program and let the drive find it and load it. With my Apple ][ tapes, I had about 10 tapes full of programs I was working on (or had typed in from magazines), and I had to keep meticulous records of cassette tape counters and the program names stored at each location on each tape, and then remember to reset the counter and rewind the tape, before I could fast forward it to the correct location and then load the program I wanted. The microdrive was so much easier / simpler / faster than the complexity of using cassette tapes on the Apple ][ (and many other early machines).

[@thomasrotweiler]

One of the essential add-ons for anyone determined to use a QL was a disk interface, preferably one with extra RAM. The disk interfaces would support 5 1/4" and 3 1/2" drives. I had double drive units of both sizes to enable more rapid duplication of disks.

[@NoelsRetroLab]

Agreed. I have some upgrades already coming, so I'll cover those in the future.

[@RWL2012]

I didn't know these "Microdrives" existed, only the "modern" 1" Microdrive hard drives

[@NoelsRetroLab]

Haha, yes. I had the opposite experience. I didn't know (or forgot) about the CF-format microdrives until someone brought them up while talking about the Sinclair ones 😃

[@raymondheath7668]

The schematic of the ULA looks like the LM324 OP Amp circuit for most cassette circuits for computers back then

[@NoelsRetroLab]

True. I don't know if there's more to it and that's just like a rough block diagram, but if so I doubt there is much more to it than that.

[@nidjcopi]

The use to be a utility that allowed multiple copies of programme files to be written to a microdrive enabling faster access, I use to use it at home with a Spectrum 48K and managed to get it working on a OPD (one per desk a QL clone) at the office, If you're interested I will see if I still have the original the modified version was left at my work when I left in '96.

[@NoelsRetroLab]

Yeah, I'd love to have a look at it. Let me know if you find it!

[@nidjcopi]

@@NoelsRetroLab I haven't been able to locate my copy (yet) but I see it mentioned on various retro software sites - Lerm tape copier - the version I had was version 7

[@melkiorwiseman5234]

Now I'm remembering when I built a kit computer and because of the technical manual, I discovered that I could change the save/load speed of the cassette tapes from the default of 300bps to 600bps or 1200bps. The trade-off was that you needed good quality tapes if you wanted a reliable save/load at 1200bps while the slower speeds could cope with lower quality tapes.

[@AndyMarsh]

My group at technical college designed a weather station controlled by a Spectrum, we leaned very early on a save our work on two microdrives every time.

[@Terkzorr]

0:09 What a dramatic zoom in!

[@NoelsRetroLab]

Haha, need to keep people on their toes! 😃

[@SomePeopleCallMeWulfman]

I remember using Quill back in the day. What a great program! Unfortunately, the QL was ignoring everything that "serious" users were looking for in a PC.

[@NoelsRetroLab]

I haven't gotten to try the Quill yet since my copy failed, but I'll remedy that soon. Apart from floppy drives, what else were serious users looking for at the time that the QL didn't provide? (just curious, not denying that at all).

[@SomePeopleCallMeWulfman]

@@NoelsRetroLab I was thinking standard ports, proper keyboard, cp/m compatibility. Sinclair wanted this to be a proper office machine, but it was just too quirky.

[@RasVoja]

World first and only computer that came with full Office. One of smarter Sinclair moves

[@gflorey1975]

Omg! A blast from the past. I loved my microdrive!

[@NoelsRetroLab]

How was it for you? Was it reliable back in the day? It seems that people either loved them or hated them.

[@gertsy2000]

Great video Noel. Thanks. I have and interface 1 and a Microdrive for my Spectrum. Haven't taken it out in a while. Perhaps I should.

[@NoelsRetroLab]

Go for it! It was pretty fun playing with them. I also have them for the ZX and should take them out again 😃

[@andyastrand]

I spent a chunk of my early teens working with microdrives, writing freelance desktop publishing software for the Sinclair QL. I think they are happy memories but it was so long ago now I'm not sure either way. Do I remember a click of death?

[@ludditetechnologies]

Another excellent video thank you Noel.

[@NoelsRetroLab]

Glad you enjoyed it

[@RBLevin]

Way ahead of it's time.

[@NoelsRetroLab]

It really was. Too bad they dropped the ball in several aspects or they could have been a contender.

[@RasVoja]

Sinclairs answer to floppy drive :D

[@d2factotum]

Just a note about the tape saving and loading: I can't speak for the Amstrad, but I know that on the Spectrum the tape routines worked by writing different length pulses for 1s and 0s--the practical upshot of that being that it would take *longer* to load a file that was mostly 1s than one that was mostly 0s! You can actually see this sometimes when a Spectrum game is loading the loading screen in.

[@miikasuominen3845]

Bought a refurbished QL from ebay, maybe 2 and a half years ago... Seems to be on fantastic condition. Never been able to try it, though. Because it didn't come with PSU (I knew it). Haven't been able to find a PSU for it. Maybe I could build one and 3D-print a connector... Maybe after another 2,5 years! 😜

[@NoelsRetroLab]

Building a power supply for the QL isn't trivial. Charlie in NZ is building them and selling them. Check on FB or qlforum. The other option, which I didn't look into, is to bypass the AC components and seeing if we can feed DC voltages directly. That might be an easier option.

[@miikasuominen3845]

@@NoelsRetroLab On the music side, they actually have AC-psus (effect pedals PSUs), that should be straight usable and coupling that with DC-psu wouldn't be impossible task. But that one seems a much neater way (though it isn't actually a PSU, but a converter. You'll still need to buy a separate PSU). I'll keep my eye on it. Also, that MD-emulator is very interesting! I kinda like to do things the easier way nowadays... But, of course, love original hardware ;)

[@10p6]

It is interesting how Sinclair used the 68008 to save money on the system architecture, yet they used 16 x 8K RAM chips which they could have used 1 Bit chips for 16 bit Data transfers with a 68000 ...

[@Starchface]

I thought these microdrives would be junk, but that works quite well. Something like this would have been great to have instead of cassette tape. They should have sold these as peripherals for different systems. It could plug into a serial port and have a machine-language program with it and it should sell for $100 in 1984.

[@NoelsRetroLab]

Yeah, if they had no reliability issues, they were pretty good for a tape system!

[@user-pk7mb9is1e]

exellent video!!!!!(i am not a fan of ql but i own a +2) amstrad 6128 floppy disks are really reliable(my opinion) - i own 20 pieces from back then and the only i did was to format them

[@justy256]

Love this channel! Inspired me to re-animate my Amiga 500. I think the video speedup multipliers you're using are off by 2 orders of magnitude? e.g. 'x300 speed' seems like it's 'x3 speed'?

[@jamesu1540]

I have kept every Spectrum from 16k rubber key to Spectrum +3. I have kept every game and the interface 1 and 2 and the thermal printer with "paper", i have 5 microdrives and two actual drives. I also have the Multiface and Multiface +3. I loved them all. And i started with a 1k ZX81 (touch keys) with a 16k additional RAM. Im glad i kept every thing. My favourite games - Daily Thompsons Decathlon, The Great Escape, Jetpack and Manic Miner

[@NoelsRetroLab]

Nice! Not many people can say they've kept all of those things. Most of us sold and upgraded, or got rid of them in moves (and invariably regretted it). I have all of those Spectrums now, but not all the way from the 80s. Those games are true classics. I spent hour and hours with The Great Escape. It was fantastic! Great memories.

[@jamesu1540]

@@NoelsRetroLab yep i had to keep them. My bro had a Commodore Vic20 and never really got into them 😂😂😂

[@nilsarnedahlberg]

Owned a Ql once upon a time. Added some extra RAM and floppy quite fast and a 3.5 inch floppy was much faster than the microdrive. One problem with the microdrive was the same you sometimes got with cassettes: the tape got caught in the mechanical parts and got wrinkled. After that it was just time to throw the tape away. You might be able to read the data and copy to another tape, but it was not 100% success rate on that.

[@NoelsRetroLab]

I bet it was a totally different machine with more RAM and a floppy!

[@nilsarnedahlberg]

@@NoelsRetroLab It sure was.

[@awilliams1701]

I was just on techmoan's channel where he was talking about the hipaq which is a format not too different to 8 track. And yeah he had to replace those sponges. lol

[@zx8401ztv]

You can slow the motor down a bit to get more storage, but speeding it up may make it more reliable. The more tape that passes the head, the better the high frequency recording.

[@NoelsRetroLab]

Good point. That would have been another option. They actually did a bunch of smart things I didn't get around to talking about: interleaved data in two channels, but even the sectors were interleaved apparently. So a contiguous file would be stored spread out through the tape, not contiguous (or so I've read).

[@galamoonretrogaming]

I have a QL but the 1st drive does not work, thank you for your video. I will try to swap with the drive 2

[@NoelsRetroLab]

Excellent. You may be able to follow a similar troubleshooting. Apparently the ULA is a very likely candidate if all the physical checks pass.

[@insoft_uk]

Didn’t quite get that bit of showing the drive now working as it was drive 1 not working we’re drive 2 was, yet after all that work you showed drive 2 now working. Apart from that great video, nice to know Microdrives did have some advantage v floppy despite their other issues

[@NoelsRetroLab]

I probably went over it too quickly, but the first thing I did was swapped drive 1 and 2 (to eliminate the possibility of being the QL itself), so at that point drive 2 was the faulty one. Is that what was confusing, or did I have some editing error somewhere along the line?

[@Samuel-ge7im]

Great video Noel

[@NoelsRetroLab]

Thanks!

[@runvnc208]

I think its a brilliant idea and a huge win compared to regular tapes. Too bad they apparently had trouble with the execution and poor reliability.

[@NoelsRetroLab]

Right. Compared to regular tapes they're awesome! 😃

[@cocusar]

Wow, that's a fast drive, even for tape based standards. I assume that the 14s overhead when seeking that fictional 100kb drive is negligible compared to the price of these drives. What a shame that they were unreliable. Do you happen to know why were they unreliable? was it because of the pinch roller, the head, the ULA?

[@NoelsRetroLab]

Not sure why they were unreliable. Apart from conflicting reports, I also read that when manufacturing passed on to Samsung (I think), reliability improved a lot. But I believe the problem was the cartridges themselves, not the drive.

[@cocusar]

@@NoelsRetroLab Ah, I see. well, running a tape at such speed is kinda difficult, even so if it's looped as an 8 track

[@preferredimage]

I'm only 5:50 in so far but I wonder if this is the same fault as mine where I needed to swap the ULA on the drive?

[@NoelsRetroLab]

If you've done the basic physical checks and they seem fine (cleaning stuff, checking the rollers), then probably.

[@preferredimage]

@@NoelsRetroLab No I meant your fault might the same as mine. Mine is fixed. it was the ULA. but I watched the rest of the video and it was the ULA. must be a common fault with MDVs.

[@salesoftheunexpected]

I'm desperate for microdrive cartridge pads, can you provide a link for where to source (UK)

[@Patchuchan]

I think Sinclair was trying to under cut the price of the Amstrad CPC with the QL. The cheapest PC compatible at the time was the Tandy 1000 which costed a lot more.

[@tenminutetokyo2643]

That is really awesome. Someone needs to make an SD reader for Sinclair.

[@NoelsRetroLab]

SD reader in the form of a Microdrive? Look no further than the vDrive. I showed it in my last Mail Day video and I'm shooting a video about it (and other QL upgrades) right now 😃

[@johnsonlam]

Easily mixed up with Compact Flash style Microdrive, totally different. Fun that I think it's a bit slower than Apple ][, as I work quiet a lot back in the old days, too bad I don't have cassette anymore to have a fair test, wish you have some fun playing with this.

[@NoelsRetroLab]

Yes, I had completely forgotten about the Compact Flash Microdrive until I started looking into the QL one. Funny how they reused the name (which is very generic to be fair).

[@gogee8510]

Love the video.

[@HelloKittyFanMan]

A MicroDrive is a _hard disk_ storage technology. But if these little tapes already had the name then what were IBM and Hitachi doing trying to use it on hard disks too?

[@DAVIDGREGORYKERR]

They are like the old 8 track music format search #Techmoan+8-Track.

[@billcameron2223]

Great video. Do you know if it's possible to take apart the disks? I have some felt lodged in one and it won't spin.

[@KeriSqueak]

Noel... uhh... (Should we tell him it's not November any more? :'D )

[@NoelsRetroLab]

Uh? What? Psshhhh... don't say that out loud! Maybe they won't notice! 😃

[@101blog]

Every Day is QL Day damn you .. you insensitive Clod ... ;-) !!

[@MadsonOnTheWeb]

I like this formfactor

[@NoelsRetroLab]

The form factor is pretty awesome. No doubt about it.

[@RasVoja]

Amiga was standalone computer, but QL is last one with BASIC in ROM

[@koenielinux3131]

How does the erase function work? I can't see a separate erase head altough the manual says 'The erase head is displaced from the write head and is timed by IC1 to sink current before the write head is enabled.'

[@user-pk7mb9is1e]

i wish i had one back then!!!!!

[@PrivateSi]

A disk drive attached to a QL was quite a bit faster than microdrives. The CPC probably had a much slower bus. If I'd been in charge The QL and Spectrum+ would have been combined into one product, with a 68008 and Z80, with 256kb memory and more memory allocatable to graphics (256x256x32 colours, 512x256 16 cols, 512x512 4 cols as well as the standard speccy and QL screen modes and palates that use less memory.. It would have run speccy software but also new dual cpu software with one or the other handling graphics, sound etc... Perfect for developers at the time... Maybe improved audio, but not a deal breaker... NO BUILT IN MICRODRIVE, but a slot and screw-on 2x microdrive, 1x disk drive, 1x AUDIO CASSETTE add-on options that matched the Spectrum QL Pro (tm) .... Would have taken over the British market place, if nowhere else... Dual CPU systems were not so rare back then. Z80 68008 combo would have kicked butt at the time and surely beats a dodgy double microdrive ... Oh well... late and rushed... Stood on their laurels, milking the speccy, having a good time, botched The Spectrum QL that should have been, meaning a naff Spectrum 128+ upgrade that only improved the keyboard and a under-developed, buggy QL... THEN DIEED!

[@NoelsRetroLab]

That would have been an awesome system! The only problem is that it would have probably been quite expensive. Still, one can dream on 😃

[@PrivateSi]

@@NoelsRetroLab .. £399 was quite expensive, but £399 or £449 with high profit matching tape deck, £499 with microdrives /disk (maybe £549 for disk) before Christmas with a few games developed, maybe 128kb and more economical but complex colour modes, courtesy of the coprocessor.... oh well... If only us Sinclair Users and Sinclair Developers had been Sinclair's main influence, instead of lazy profit maximisation...!

[@m4rgin4l]

I'm wondering if it might be possible to fake a microdrive with the same setup as the fake cassettes with audio jacks.

[@NoelsRetroLab]

Yes, I have one on its way here. The vDrive QL. It will allow me to explore the catalog of software for the QL in a more reliable way 😃

[@weirdocollector]

@@NoelsRetroLab got one QL vDrive and it's a great device. Better be used with the internal board that redirect the addresses of the internal microdrives to the external ones emulated by the vDrive

[@tamasmarcuis4455]

Innsmouth swim team LOL

[@Ratzfaz]

7:28 wondering about the Listing lines 270 280 and 170 180 is this correct ? and 300FF Where is this procedure used ?

[@NoelsRetroLab]

You know, you're totally right. I just copied it without thinking too much about it, or digging to see what exactly those POKEs did, but the fact that the POKEs after the IF statement do the same as the ones before it makes it pretty clear that there's a typo there. Probably in line 270 it's supposed to be ,3, just like when we did the write. I wonder if that changes anything. Hmm...

[@WacKEDmaN]

great wrap up to the series Noel! really makes me wonder why they didnt just use cassette tapes.. sure it was aimed at business and every 5th home had a computer with tape drive so they wanted to differentiate.. but.. reinventing the wheel is never a good idea!.. always better to use whats standard and tried and tested.... but i guess back then they where still working out what works and what dont... for desoldering the ULA...i woulda just removed the motor to get access to the back of the PCB...im assuming there would have been enough room to get ya soldering iron in there... oh god i love that tape loading sound on the CPC!... love it so much ive been decoding HF weather fax radio transmissions coz they are pritty much identical signals!.. just wefax is much slower baud rate tho!.. 60 "scan" lines per minuite!

[@NoelsRetroLab]

Cassette tapes were MUCH slower and they weren't random access (check out the benchmarks towards the end). They should have gone with floppies!

[@WacKEDmaN]

@@NoelsRetroLab im sure they could have come up with some way for tapes to have random access (wasnt there some random access "backup" drives for old PCs)... like these microdrives are tape based.. there must be some encoding on the tape or mechanical counter thats telling the drive where it is along the tape...

[@rog2224]

​@@WacKEDmaN I seem to recall it being hard on media, since you have the read/write head in contact with the tape at an unclutched speed. When the location is found, the capstan engages, and the action is carried out at a more sedate pace. Techmoan probably has a video that covers it in some depth.

[@BertGrink]

@@WacKEDmaN Philips did indeed come up with a system for encoding position information on a linear tape, but it was only (as far as i know) implemented on their own Mini Digital Cassette mechanism, which used tapes similar to those dictation machines that were popular in the business world. These drives used MiDiCOS, short for Mini Digital Cassette Operating System, and it wasn't exactly cheap, as i remember it. However, pricey though it was, it _did_ offer the user a Random Access facility. As with so many innovations in the 80s, this one didn't last very long either, and floppy disks became the standard, as we all know now.

[@WacKEDmaN]

yeah it cant be "that" hard to do... im sure a standard cassette tape would have worked...eg just use one of the read/write heads that can read both directions.. and have the tapes "single" sided.. as it writes out your program... its dropping a signal on the 2nd side that encodes the distance from the header/contents of the tape...( or maybe ya had to "format" the cassette first to write out the encoding and setup a TOC area)

[@karolwojtyla3047]

It's amaizing that the microdrive is faster even than a floppy disk, or maybe Amstrad floppy drive/system is so slow? How about compare to Spectrums fdd? although Spectrums 3+ drive come from Amstrad so it should by similar.

[@NoelsRetroLab]

I think it's amazing how fast microdrives were. I don't think 3" disks were particularly slow, so that says something.

[@peddersoldchap]

Hi. If the felt is replaced, is the cartridge always functional?

[@steverpcb]

Years ago I wrote a program (specy basic) that would present the files on a microdrive as a numbered menu so that I could just press a key and it would auto run the file. It read the text on screen with chr$ to get each file name.

[@NoelsRetroLab]

Nice! Did you make it the bootable file? Although I'm not sure if that's possible in the ZX Spectrum. In the QL you can name it BOOT and it autostarts.

[@steverpcb]

@@NoelsRetroLab If I remember correctly it was RUN"" and it auto ran, it was at least 30 years ago :) I still have the specy with a DK'Tronics Keyboard :)

[@raysymonds7147]

If the tape, loops 1 time per minute and You write a 30 sec file and the drive stops the tape at the 30 second mark, when you time a read from that point, aren't you timing the 30 sec to where the tape begins and then the read time ?

[@chriswatson2407]

I had a QL, 48k Spectrum and two microdrives that I got very cheaply from a bargain bin in an electronics shop. I found them unreliable. Would love you to demo the QL applications.

[@NoelsRetroLab]

Bummer. I hear a mix of opinions from people who used microdrives back in the day. Some say they worked great, and some that they had lots of problems with them. I'll definitely check out QL applications as soon as I get the vDrive QL (an SD-based microdrive emulator!).

[@matthewday7565]

Cassette loses a lot in the audio side... remembering the BBC Micro which used 1200 baud with one cycle of 1200Hz and 2 cycles of 2400Hz - with a direct digital read channel, that could easily be turned up to "Manchester encoding" with half a cycle of 1200 and one of 2400. I also recall writing a program for the old Atom which could read in a tape in the awful 300 baud distribution format and then write one in "fast COS" 1200 baud - on the Atom, that needed either an accessory ROM for fast COS, or a poke command or two to enable it.

[@GenialHarryGrout]

Tape is fragile, microdrive tape even more so. I don't remember having any problems with microdrive tapes on my QL. I did have a keyboard problem which I managed to have fixed, it wasn't anything major

[@NoelsRetroLab]

True, I didn't mention in the whole series that keyboard membranes seem to fail quite a bit. I was lucky this one worked, but I hear most of them fail over time.

[@frankowalker4662]

The reason saving to M/Drive takes longer than loading is that the whole loop is scanned for the most sequential number of empty bytes for the file size.

[@NoelsRetroLab]

Oh interesting! Although there's some caching going on as well, so that might even things out a bit. I'm surprised the OS can't determine that by looking at the directory information. Also, I hope directory information is cached in memory, right? They know when a drive is removed.

[@frankowalker4662]

@@NoelsRetroLab I don't know about the QL, but on the Speccy the info is stored just on the cartrridge. If there is a long enough pause between loading parts and you swap the carts, the Speccy gets lost looking for files that don't exist. LOL.

[@darrylteichroeb9132]

OMG, sorry all, but I'm so glad we had the Commodore 64 in Canada. C=64 is like a fine car, while Amstrad stuff looks like a cheap lawnmower. Uggh.

[@MrLarryl79]

Is it any chance to get the basic code on Github or pastebin? Thanks

[@danmacdonald5166]

Wow microdrives never heard of them before.

[@NoelsRetroLab]

There's a reason for that! They were an evolutionary dead end. Bad choice, Sinclair!

[@RasVoja]

You had to be English and Spectrum lover. To cassetess and with 48k game or app size, fast and cheap 100K microdrives were revolution. AT QL time much less

[@raysymonds7147]

So, if the tape runs at only 1 speed means that read and write should be the same time ! If write time was 7 sec and read time was 10 sec then there was 3 sec of free space before the beginning of the file ! Also what happens if the file is too long and might overwrite the beginning of the file ?

[@okaro6595]

1:10 Double density. Single density was about 100 KB/side, double density about 200 KB/side. Single density was pretty rare.

[@nutsnproud6932]

I had a Spectrum with microdrives and worked in a shop repairing 8 bit computers. I avoided buying the QL a a result. It is a shame Sinclair did not have an official floppy disk upgrade.

[@NoelsRetroLab]

Definitely. There was a floppy disk and a hard drive adapter, but maybe it wasn't a Sinclair one (and probably the hard drive would have been hugely expensive back then).

[@RasVoja]

It did have from community

[@Xoferif]

Breaking news: EU to outlaw the use of child labour in the entry of BASIC listings. ;-)

[@NoelsRetroLab]

We used to type listings from magazines for hours at a time and we called it fun! 😃 Actually, kidding aside, that's how I learned a lot of programming.

[@Xoferif]

@@NoelsRetroLab Yes, me too. There always seemed to be one or two errors in the listing for you to find and fix, too, which was great experience. =) Anyway, great to see the younger generation taking an interest, and thankyou for another excellent video!

[@WacKEDmaN]

i remember getting a book for the cpc that was full of listings...but the book had these weird characters printed in the strings, little triangles.. we (my parents and myself) could never find the right key!.. we spent many hours typing stuff in for it to either be buggy (from typos)..or wouldnt look right due to the weird characters... long story short.. many years later i revisited the book... to read in the first couple of pages that the triangle character in the book just represented a space..they where just put there to make it easier to see how many spaces where needed in the string!... oh boy did i feel dumb! :P

[@bobbus_74]

We can carry on in the UK thanks to Brexit 😂

[@ed731pdh]

Slave Labour - It gets s**t done. :D

[@pev_]

I had the impression (don't remember from where) that the microdrive tapes used a "folding tape compartment" instead of the tape roll that you showed at the beginning! Were there perhaps both versions made?

[@NoelsRetroLab]

I don't know. I didn't see anything about that folding tape compartment in my research. And all the pictures of opened cartridges showed that single loop.

[@pev_]

@@NoelsRetroLab Yeah, maybe I did mix it in my mind with some other endless loop tapes that use the folding tape system instead of the tape reel because it just sits more comfortable with me. I never quite got how the endless tape with a reel could work without binding :) Think about it: it takes up the tape from the center of the reel and puts it back on the outside of the reel which means the linear speeds should be different! I cannot take that! Of course it means the tape must slip around the reel and against itself but how they got that to work...

[@jaysinha0]

Definitely a continuous loop.

[@danielson9579]

Nice work 🙂👍

[@NoelsRetroLab]

Thanks ✌️

[@TaberBucknell]

That was really interesting (29 minutes went by fast!). I’d never seen the microdrive format. Does it encounter similar problems as 8-tracks like tape stretching or binding? Request: Would you please do a video on desoldering techniques? My soldering technique is iffy ... but my desoldering technique is way worse.

[@NoelsRetroLab]

Thanks! I read there was definitely tape stretching going on but... you reformatted it and got more sectors out of the tape. Sounds kind of crazy but apparently it worked! I considered doing a desoldering tutorial, but given that the soldering tutorial video is my least viewed one, I didn't rush out to make one 😃 I'll probably end up doing it anyway since a lot of people have requested it. So it's on the list! 👍

[@loganjorgensen]

Had some impatience lol, ULA seems broken, let's look at every single way it is broken...when is he going to replace it yikes. ^_^ Never had anything like this but I've been interested in other tape based data deck solutions of the era, how much they hold and the speed of them. Timing is funny because 8-tracks are just old enough to not have connected with the first home computers, a few years closer and there would have been games on 8-track heh.

[@NoelsRetroLab]

Haha, yes. Well, I wanted to check all the easy stuff first and also, I didn't have a spare ULA until 2 hours before releasing the video, so I left that for last! 😃

[@Baron3D]

You should compare with a QL+disk.

[@NoelsRetroLab]

I will. I'm getting a FDD for it, so I'll be able to try that combination (at least with a Gotek).

[@Baron3D]

If you have a memory expanded QL it will be quite fast.

[@mikipank]

I can't find links for more QL videos in description, as you say so?

[@NoelsRetroLab]

You're right, I had forgotten to add the link to the playlist. Fixed! Thanks for the heads up.

[@Lemonidas75]

Innsmouth diving school t-shirt :D heh heh

[@NoelsRetroLab]

Hehe, it cracks me up when someone notices 😃

[@erbake]

Hi Sir, I'd like to know if these computers are your own property, and if so, do you sell these ?

[@NoelsRetroLab]

Most of them are my own or ones from friends that I repair for them. I will occasionally sell some if I have extras though (usually on Ebay or on the sale channel of the Discord server).

[@philoffhistree6700]

which model hantek is that and is it any good

[@NoelsRetroLab]

It's a DSO5202P and I love it. Highly recommended!

[@joveaaron-real]

Hello Noel! Do you like Spain? I do. I'm actually Spanish.

[@NoelsRetroLab]

Me too! 😃