Michele's Haunted Diablo Drive 

I know where one of those Diablo disc drives is. In fact the last time I saw one, it was this one - the Science Museum in London. It's in the 1970's gallery, about 50ft from the Apollo Command Module, on the EMIScanner MkI CT scanner from Atkinson Morley's Hospital in Wimbledon. It was the prototype Clinical CT scanner - the first one in the world - and I used to look after it. In fact, I helped dismantle and ship it off to the Science science museum myself. I treated myself to a visit there about five years ago - I knew it was there somewhere. When I found it, the hair on the back of my neck stood up. It was so cool seeing history, displayed in one of the best Museums in the world, and I was a tiny, tiny part of it. My finger prints were probably still on it somewhere!

That drive really is possessed....now the ceiling lights starts flickering ;) Love these problem solving videos by the way, keep up the good & interesting work.

In my first job out of university I was a test engineer at Data Recording Instrument Co on England, the UK manufacturer/distributor for Diablo, and worked on these disc drives. Amazing to see one working some 45 years later!

the combination of knowledge, test equipment, spare parts and determination needed to do that repair is amazing

Tech comes and goes but core troubleshooting never goes out of date.

marc, i cannot tell you how much i appreciate your content. you’re incredibly inspiring. thanks for doing what you do.

Your videos are a textbook study in perseverance. I am always impressed how “never give up, never surrender” is the motto you guys truly follow to the end. Great job!

Such positive determination, amazing to watch - thank you - you're all my kinda gods. I cracked up seeing how quickly you boxed and got rid of that haunted thing once it was sorted... before the water in the house turned red.

Come on, what do you expect from a hardware which is called "Diablo"?

Another fabulous video, thanks Marc. I sure would like to find out more about Carl's FPGA Diablo exerciser, as one day I'll get to attempting to power up my own Diablo 31's and I'm sure it would be an invaluable tool. I don't have an alignment cartridge though, so that is going to be extremely problematic.

Interesting - by the late 1970's I was programming on Singer/ICL 1500 series machines that used the top loading PERTEC drives. The chips in the circuit board looked to be from the 2nd half of 1978. And you had what looked to be the front panel from an IBM 360 Model 50. Neat stuff!

Great detective work, and sheer determination. I wish I had an o'scope that fast, then I could do TDR on my RDRAM PCB traces, and find out badly mismatched it is. lol

Holy water and electronics is a good combination! *bzzzt*

What a debacle :) I'm glad most of these problems were alleviated by the time the Quantum and Shugart 8" HDs were introduced. The only problem with the Quantum q2040, q2080 I've seen again and again is the bumper pad which deteriorates and becomes a sticky mess.

With all your expertise and equipment, you guys can easily charge $1000+ per hour. Great job! I hope that drive doesn't get damaged on the way back to the customer.

We used to say "Doesn't need a technician. Needs a priest." 🤣

The red button on the right of the front panel was a write protect feature! I used to be a field technician based in the UK, 70's/80's. Visited many customers who complained that their new drive reads, but won't write. I arrived on site only to find you write protect was enabled, sometimes the bulb would blow, so the customer had now idea!!

Thank you so much for sharing these kind of videos! its amazing the attention to detail you guys put into everything and amazing how you guys came up with a solution to it! :). Looking forward for the next one! :)

Years ago I worked on very similar drives (Pertec) and replaced many many heads. Once or twice would get drives where the heads were layered with aluminum from the platter (really bad crash the heads will scrape off all of the oxide layer and pick up the metal)

A place I used to work at back in 1984 routinely repaired crashed heads in the fixed drive side of a Honeywell Hawk Drive by removing the heads and sanding them with fine sanpaper and washing them out with high grade alcohol. It was quite a sight.

"Time domain reflectometry"... sounds more like something I would expect to get on the fourth floor of my local hospital... ':-)

I remember a Diablo drive in the 1972-77 era used with a honeywell 316 computer. The removable cartridge "disk" contained the data of the topography we used in a Naval Gunfire trainer at Naval Amphibious SChool in Coronado CA. It interfaced to Naval gunfire computers. Teams would simulate a navigated ship track, Fire simulated naval ship guns and the computer would compute where the shot landed. Results would show on a video terminal and a training operator would communicate to the "shipboard" simulated teams corrections Up, down, right or left. Then the "guns" would fire again. If all was done correctly the new "projectile" would land on target. Since the diablo cartridge contained the "terrain" if the shell that was fired hit a hill or mountain of course it did not land in the correct place. Lots of ships trained their personal in a simulated environment, saved shells, and no one could be hurt as in live naval gunfire. Fond memories from years past

The power of CuriousMarc compels you!!!

I remember those from MDS Mohawk 2400 computers, some of my machines even had three or four of those drives installed!

TDR was a good call. I use a phone co specific one (it's internally calibrated for underground phonelines). So damn useful!

Hope you can make another alignment disk.

Last time I commented this early on a video the germanium transistor was invented.

The Power of Tech Compels You... what is the model of the compact computer on the trolley next to the desk at 8:32? Just curious. I recognise it, but can't remember!

Thanks for the video Marc: Tektronix 7854 /7S12 with an S52 and S6. You should do a video on the 7854; it would be very interesting.

I bet we could modify the Alto microcode so that it doesn't do that write. Sounds like a fun trip into ancient lore.

I look forward to your videos well above any of my other subscriptions.

Congrats on being so persistent, and now just like on Monty Pythons meaning of life - "and now zee cheque". Can you make another alignment disc or was it make on a high accuracy drive? Also, love the Tek TDR / modular scope. Sadly when I was studying electronic engineering I never got to play with a TDR even though we learned about them :-(

Very nice. Also love to see the 7854. Looks like in my own private lab :)

hopefully, the drive won't get damaged during shipping. the heads appear to be very delicate.

Have you tried moving it from the curry lines?

Absolutely awesome stuff. Great video.

I'm curious (haha) to know how easy it was to acquire replacement heads.

Remember, when it comes to hauntings: Possession is 9/10 of the law! :P

You have exorcised the demons. This drive is clean! Job well done!

Is it possible to create a new alignment cartridge with some creative hardware hacking?

We had the same type issue with a Diablo drive. This was back late 79 or 80. Turned out the terminator on the back of the drive was the problem!!!

are those heads hard to find? Any chance to repair them?

I know these drives from the seventies. Repaired the logic boards and fixing crashes. With some luck, sometimes crashed heads could be cleaned and reused. Their price was few hundreds of dollars (for a 2.5MB drive)

I have a similar drive from a CPM machine, and an s-100 “Sasi” card. Do these get to “ready” without a computer connected? Mine scans then sits, ready light never comes on, but I don’t have it hooked up.

You should have thrown in "The power of Thacker compels you!"

In a few years hopefully someone will design a diabolical-FPGA fixing my ZIP drive. Click of death changed my view on technology. :)

Will you guys be involved with the NASA/Kickstarter project to restore mission control?

is that huge disc a hard drive? wow thats old....and is that the first Macintosh @7:31?

Is that a fancy house decorated with old computers? I worked for Bell Laboratories for 30 years, and always had a laptop running windows. The machines i worked on 3b15, 3b20, pyramid 2000, sun, compaq, etc. and running unix. Lynix, etc. programming in Informix, Sybase, Oracle, etc. are behind me. Last thing i would want in my house is old computers i used at work.

What is the computer sitting to the right of the drive, a 9825?

The scariest part was when it turned its head around, spewing bits all over the place. (The accessible/observable complication of these old drives versus the hermetic isolation of modern ones reminds me why I bought an RX-8: I have absolutely no clue how a Wankel engine works, so I’ll never be tempted to use my time to work on it.)

I found this video particularly educational...

@20:14 back in the day, i had to add a terminating resistor onto my windows hard disk daisy chain. My memory fails me, but i do not believe i needed to use a soldering gun, just a jumper block

Wow! You guys rock! Amen!

Who knows, someone might bring you an RK02 drive someday.

I wonder if there is ways to obtain or recreate the machinery for rebuilding platters of those disks. Would solve a lot of problems and relieve some strain breaking a unique alignment disk while working on.

Diablo Repair Service. I suspect your world wide customer base is pretty small. Then again, you can charge as much as you like...who else can do it?

How many Alto computers are there in the world?

Is that disc platter the same as what was used in the Digital Equipment Corp's RK05 drive?

Figgin amazing !!!

20:25 That solder pad right next to it., I assume it's the existing resistor, looks dry. Perhaps the error was a loos solder joint? Hard to tell from the picture. I bet you got a better look. But from here it looks dodgy.

Rolling blackouts...does he have a Cornerstone microturbine on his vast estate?

Can you tell us some more about your TDR... or point us at a video if you already have. I love your pronunciation of "diabolical"

We need an young priest and an old priest :3

Backplane issue?

Why were the lights flickering, something wrong with the supply to the house?

13:00 So it's sending a Dirac impulse into the cable, and evaluates the impulse response?

wow some old stuff should go to the landfill.. you guys are not to be defeated!

I never seen a disk drive that big before

I'm sure you could have saved yourself the trouble by shorting out the ghost with some holy water.

Applause ! This episode would've made a great comedy sketch :) Especially the part from ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-yLocGtRxhp8.html onwards made me really laugh!

Worked on these on Prime systems. Pertec version also.

Had a cdc 300 mb….faulted every time it tried to write. Power cord was shorted to chassis. Knocked me on my ass.

Oh, hi Marc.

Trickey those digital lathes

Not sure about the audio. Seamed a second out.

What about using a 512GB SSD they are not that expensive and you can get SCSI2SATA. if it has been connected to the internet then it has got infected by some nasty virus so I don't think that there is a way of getting it back, or is it much more engrained that it has totally reprogrammed the ALU so as to screw up any disc you try to read.

Power delivery

Only watched half the video so far, so haven't seen the solution to the problem. I'm going to guess it's a power supply issue? Edit: Nope, I was wrong. Damn

1:08 smh

11:06 XORcist

Michele with a trailing E... feminine gender ! ?? Looks a lot like a DEC RK05 drive.

I hope you send her a good bill for all your hard work and ruined heads.