You're the only one to make a video showing the inside of these! Thanks for the interesting video, I've wondered how those worked

@gabrielgarza3707

6 жыл бұрын

LeiserGeist Bobby

@Rascal_the_Raccoon

4 жыл бұрын

*That boy ain't right.*

It's rather beautiful to watch that tape machine work. The action of the reels is rather soothing and hypnotic.

@jochenstacker7448

6 жыл бұрын

I'd have it over a lava-lamp any day.

@dokbob5795

6 жыл бұрын

It was more than Hypnotic. I worked for Honeywell in the sixties and one customer Unbrako in Coventry England had eight tape drives. I used to run systems check which operated EVERYTHING. When these monoliths ran, writing, reading, fast forward and fast back, it was like an orchestra playing. The low growl when reading back and the high pitch on the rewind. I wish that i could have recorded it. Music to my ears.

@Microsoft-Windows

6 жыл бұрын

You think of the detectives waiting for the investigator researchers to get a computation result. The tapes are spinning and the film noir detective is waiting and pondering what the results could be alas an op code is invalid.

When I was a boy in the '80s I used to think that every time an old movie or TV program showed a mainframe's tape unit, their prop department had gotten it wrong. I was used to playing around with my father's old Akai reel-to-reel tape recorder, and my grandfather's Wollensak -- the reels both turn in the same direction and at the same time. It wasn't until many years later that I was able to research IBM's vacuum-column technology and appreciate how innovative and impressive their tape units were and still are.

@KarlHamilton

3 жыл бұрын

Same here!! Thought I'd try to find out what was happening :)

@mikefochtman7164

9 ай бұрын

We had some old mini-computers that used 9-track reel-to-reel tapes like these (but not exactly, ours were made by Pertec). When we had some 'suits' scheduled for a tour, we were told to 'Make it look like the computer is doing something'. So we would queue up an old tape-to-tape sort program (even though we normally did large data sorts directly to the disk drive). So when the 'suits' came in, they got to see the reel-to-reel tapes jerking back and forth, just like old movies and they were duly impressed. lol

Blue screen "Read/write error sector 00001011" IT technician starts the lathe. Awesome video!

@zfoxfire

7 жыл бұрын

Locutus of Borg encountered a write error at sector 001

@user2C47

6 жыл бұрын

Maybe because all the Borg were sleeping.

@andrewallen9993

6 жыл бұрын

Benoit De Brueker Naaah, oscilloscope!

@LoganDark4357

6 жыл бұрын

Sector 11 in big-endian? Or sector 208 in little-endian?

@ashkat64

6 жыл бұрын

We're talking about an IBM machine, that'd be a read/write CHECK ;)

I would never had guessed the existence of that vacuum tape buffer system. It's like a mechanical cache, genius.

Many years ago I refurbished an IBM 727 tape drive (predecessor to your 729). The 727 had vacuum tube logic (plus lots of relays), but the motor drive design was almost the same as your 729. The brushes were OK, but the powdered iron and graphite mixture inside the tape reel shaft clutches had rusted so the reel was trying (unsuccessfully) to turn both ways at once. Disassembly, cleaning, and reassembly of the clutches was a real chore! But I got it all working OK after troubleshooting a bunch of the vacuum tube logic - and learned a lot in the process.

Flew out to fix another brand VC tape drive once on a support call. Tape kept sticking / snapping in the columns. I finally found some kind of sticky goo in the back corners of the columns. I asked the customer what they were using to clean them... It was wintergreen rubbing alcohol, which contains a plant oil/sap.. Cleaned them with pure alcohol, and it ran perfectly. Informed customer about proper cleaning chemicals..

All that size, mechanical complexity, and electricity - and even an old junk 286 could outpace this machine with ease. It's astonishing how far technology has progressed in such a short period of time.

@vap0rland

5 жыл бұрын

"even an old junk 286 could outpace this machine with ease" - actually no, these systems supported hundreds of terminals simultaneously. What they had that your 286 is lacking is THROUGHPUT Every peripheral device in the system had an intelligent controller that was an entire computer in itself. I know because I was a mainframe computer operator in the 70s and 80s - you could not imagine a more fascinating job or place to work.

Fabulous Video !!! I spent many hours inside the computer room of an IBM 360 and I was always amazed at the incredible speed and quickness of those tape drives, and the slack tape hanging down inside their vacuum chambers. When the IBM repairman came around, he was dressed in a suit and carried a suitcase full of the most beautiful exquisite tools. The type you might see in Switzerland. IBM made precision top world quality machinery, and the tools to maintain and repair IBM equipment were equally impressive.

@DevynCairns

9 ай бұрын

Repairing mechanical equipment in a suit sounds like a challenge. I'm sure they had to get them dry-cleaned often too.

0:02 Notice the large panel flooring in this IBM 360 computer room. All the wiring and cooling for the machinery ran under the floor. The computer itself required this specially-built room, and computer rooms all looked quite similar in every company which owned an IBM computer. Beautiful space-age modern equipment. It still looks futuristic six decades later.

As an ex Magnetic Tape Drive Engineer working out of the UK - see this problem and how you resolved it brought back many sweet memories. Awesome work. I was smiling as much as you all were at the end. Bravo

One thing I don't miss, cleaning the read/write heads. We experimented with different brands of tape, and finally bought a 'tape cleaner' that would zip the tape quickly from end to end, dragging it over a sort of 'cleaning head' so the old tapes wouldn't leave dirt on our tape drive heads.

It's astounding to me the ability of the enginiers to design around the things they couldn't do in electronics.

A little bit of electronics ? Geez, will you look at all those discrete components boards ! And 8 motors ! Wow ! What an incredible piece of engineering. No wonder it was so expensive back in the day. Fascinating piece of machinery. Thanks for this detailed inside view and explanations. Congrats to all of you on fixing it. This video made me subscribe. What is the maximum digital data transfer speed of a tape unit like this ?

@wsxyz

7 жыл бұрын

The maximum data transfer speed of this particular unit, a 729-II, is (6 bits per character) times (556 characters per inch) times (75 inches per second) = 250,000 bits per second. Other models of the same drive with a faster transport (112.5 inches per second) and higher density (800 characters per inch) could transfer up to 540,000 bits per second.

@simontay4851

6 жыл бұрын

540,00 is only 67.5 Kilobytes per second or 0.067 Megabytes per second. Yes, it really was that slow.

@stephanweinberger

5 жыл бұрын

Actually this hasn't really changed with modern tape drives like LTO; still a handfull of motors in those, just at a miniaturized scale.

@stephanweinberger

3 жыл бұрын

@SteelRodent yes I know the struggle firsthand :-) I was referring to the original comment about the mechanical aspect and the number of motors.

@ilgiusto6885

3 жыл бұрын

@@simontay4851 same my internet connection...!

So iconic... I remember how computers were represented in any cartoon, until the 1980s: a cabinet with two reels 😊.

Three years late into a thread, as usual, that's what the KZread Algorithm does to me. This brings back many more memories, although I have to say, these brutes are far more complicated than the CDC machines I worked on in the mid seventies. That kit was probably mid to late sixties in origin. The CDC's were vacuum column machines, but there the similarity ended, pretty much. The Reel Hubs were direct drive, reversible motors - quite meaty things - but none of that coaxial clutch, slip rings and fast rewind motors. I think they had five motors, including the vacuum pump. Two reel motors, the vacuum pump and the two capstan motors. The capstan was a finely ground, forged (I think) cylinder about 75mm in diameter and a bit wider than the tape - say, 15mm? The circumference had a series of semicircular groves, not quite full width, with a hole drilled into the plenum chamber underneath. Now that I think about it, there were probably two capstans, although I just don't remember. One for forward read/write, one for reverse read/write. I'm almost sure they could do that? So the capstan/s(?) were on either side of the read/write section and the left one hauled tape out of the supply column and the right hand one shoved tape down into the take up column. Next to the read/write head was a fixed block with holes in, which was the tape brake, also vacuum operated. They revolved at constant speed (the read/write speed) in the appropriate direction and the tape was moved by sucking it against the capstan. To stop, the vacuum was released on the plenum and applied to the brake. There was virtually no momentum because all the mass was being driven by the reel motors and controlled by the columns. Loading a tape was very easy. You just pulled the leader off the supply reel as it hung down and pulled it across the top of the capstans, the brake and the heads and wound it on to the take up reel. Then you closed the door and hit 'LOAD'. The vacuum would come on and suck tape down both columns until they stabilised, then the tape wound forward until the EOT marker was detected. Then the READY lamp would come on and, with any luck, the deck would go online automatically and work could commence. I have other memories about slip rings, but that was on CT Scanners and many, many years later. Thanks for a great series, Marc.

Every part of this is a learning experience. I'd never even heard of silver epoxy. Now I'm left thinking of all the things that would have been the perfect tool for and I'd kludged. Well, if all you have is a hammer, everything looks like a nail.

Well this neat, back in 1996 my electronics class disassembled a 1401 series computer, 720 tape drives and backup power system as a class project. At the end it all was sold as scrap metal I did manage to keep one tape machine (I bought it for $50) and got it working, It's in my storage building now bubble wrapped up and tarped.. Along with a honeywell mainframe and hard drive rack. I have a personal collection of vintage communications and computer hardware. I have one of the original World of Warcraft server blades also.

@NeuronalAxon

4 жыл бұрын

What's the spec of the WoW blade?

@hiteck007

4 жыл бұрын

I'd buy the Tape drive & disk drives. But I already know your answer. lol was worth a try to get a bite

Are those gentlemen in red shirts former customer engineers? Imagine repairing these in the old days with your white shirt and tie on (required) to project the air of professionalism. Many white shirts were ruined and no expense reimbursements. IBM had boat loads of part numbers! Once an amazing place to work with a great group of amazing people!

It's amazing how much length they went through to run that tape at speed.

The era when there was money to be made in IT! IT technicians using lathes - brilliant. Now technicians are on the minimum wage, sad times.

I had a job when I was 13 (1979) at our city municipal building, loading tapes, changing printer ribbons, and loading punched cards. the equipment was the same or very similar to that. my mother altered my birth certificate so they would hire me.

I love the mechanical solutions to electronic problems all through-out these older machines

OMG!!! my C: partition belt tensioner has broken

We all need to stop & appreciate how these machines paved the way to the technology that we have today that we can wear on our wrists

Computing in the 50's/60's was a noisy business....I love it!

I'm shocked by how complicated the inside of that 9-Track tape machine is. In the 70's I worked at SoBel date centers in Miami and Ft Lauderdale, as part of an on-site maintenance team of three guys. We had about 40 or more Telex drives, I think they were 6450's. The reel motors were direct drive no belts, no clutches. The capstan motor, there was only one, was a permanent magnet motor with an armature that was a fiber glass disk with heavy wires bonded to it that was about 1/4 in thick and maybe 8" in diameter. The capstan wheel mounted to the armature had vacuum applied to grip the tape. It had to accelerate to full speed and write it's block of data and decelerate to stop while maintaining the about 1/2" gap between blocks of data. It had about five to six vacuum switches per tape column. And I really did love my job. All these machines were very well engineered, and were workhorses. It was great fun.

@GH-oi2jf

Жыл бұрын

These are 7-track drives.

@rpk5568

Жыл бұрын

We need a place to send the pictures of the data centers we worked at. Tape drives at Sobel were made by Telex. When I starterd at Sobel they were using an RCA 3301 computer. I had zero IC's in it. And a lot of sketchie board contacts which were all gold plated. Core memory was in a sealed box. Used a daisy wheel printer as a console. Later changed to an modified IBM Selectric.

you should see 8 tape drives doing a sort! You specify the input drives, how many work drives, and the o/p drive. while 1 i/p drive was in rewind it was reading from the other. that was called phase 1, the input phase. then phase 2 was the sort phase, then finally phase 3 was the o/p phase. after phase 1 (i/p phase) you can mount scratch tapes on the two input drives, then the printer will tell you how any passes of the data has to be made to have the data in sequence before the final phase 3. simply amazing! tape sort were much faster than disk sorts too! watching the tape drives reading and writing both forwards and backwards during phase 2 was very cool. I used to write sort exits in assembler, for the sort program. these exits can modify the data on all 3 phases. all this was done on a machine with 16K, that's 16 thousand bytes of memory!

@CuriousMarc

7 жыл бұрын

Absolutely. Filming a SORT7 run is on the to do list.

@simonknights7526

4 жыл бұрын

So many memories of watching tape sorts on 2401 drives on a 360/40. I do miss that on modern machines.

@rty1955

4 жыл бұрын

@@simonknights7526 actually tape sorts are MUCH faster than disk sorts. I used to know the programmer reslonsivle dornthe sort program and wrote tons if E15, E25 ans E35 sort exits. The sort program would constantly evaluate rhe best algorithm to use as the sort progressed. What i find amazing is that on a tape sort, you can specify the specific output drive even though it is used as a work drive as well. Also after the input phase is done, you can use the input drives as wirk drives After you mount scratch tapes on then. You could also use alt input tapes drives as well and both would be used as work drives adter the input phase. It was amazing to me that after the input phase, it would display hiw many passes of the data it would take to complete the sort.

@simonknights7526

4 жыл бұрын

@@rty1955 Interesting! But I don't understand how the tape sorts were faster that disk sorts - could you explain please? The first machine I worked with only had two 2311 disks (7.25MB each - one held the OS, and the other had the Fortran and Cobol compilers, and other support libraries) so could not be used for any sort work areas. When those 2311s were replaced by a number of 2314 disk drives we then switched to using the disks as work areas for sorts -because sorts were so much faster that way. But watching a tape sort was something else!

@simonknights7526

4 жыл бұрын

@@CuriousMarc Did you film the SORT7 tape sort? I've looked but can't find it - would be great to see!

Wow. I'm blown away. I think there's as much mechanical work involved in this machine as electronic work in some modern systems. These are the days when finding bugs involved real bugs lol.

Wow, I saw the inside of these giants for the first time! It is like "when computers used to look like heavy machinery!"

Just a bunch of old computer nerds. I am jealous. As a child of the 80s I have never had the chance to learn much about these old drives or tech of the pre home computer era.

These old tape drives brings back memories, the vacuum tape drives were far better than the modern drives that were attached the AS400 computer in the early 90’s. In that day there were ancient tape drives attached to a 4381 but boy were they fast. In those days IBM built quality and I was proud to work for IBM.

Watching the brushes being made was so oddly satisfying.

It might be ancient, obsolete & nowadays a watch calculators probably millions of times faster & more memory efficient, but I was fascinated by the complexity of these wonderful pieces of engineering.So much so I want to know where I can buy one!

@herrbonk3635

3 жыл бұрын

No, it was much more memory efficient in the 1950s than it is today.

Every War Games fanatic would love to watch these old tapes going back and forth! I think Iron Eagle movie shows these as an Air force data center...

I've seen these tape drives in countless movies,TV shows, etc...Never knew they were so intricate

The sound of that computer room brings back memories. They even have the raised floors ...love it.

Great video! I love 1401s, they were such a big improvement over the 402 accounting machine! Spent many happy hours programming these puppies. Almost wish I had one. :-) One minor correction - disk drives existed at the same time as these tape drives. All the 1401 systems I used had multiple disk drives and no tape drives. Tape access was generally faster than disk access if you were doing a sequential update job, but a compile from a disk drive was a heck of a lot nicer than compiling from tape!

@CuriousMarc

7 жыл бұрын

OK. I thought the 729 vacuum column tapes predated the RAMAC (first hard disk) by a bit. I'll double check. But yes, later on you could hook up a RAMAC disk unit to the 1401. [edit] Indeed you are right: 729 tape is 1958, and the first RAMAC is 1957!

@wsxyz

7 жыл бұрын

However, the 729 was first introduced as a minor modification of the 727 tape drive, adding a two-gap head. The 727, in turn, was an improved version of the 726 tape drive from 1952.

When this system goes down... They have to call a mechanic not just run CC cleaner...HAHA!

@andrewallen9993

6 жыл бұрын

xpez That's why they called us computer engineers, NOT mechanics.

@wanjaschonecke455

6 жыл бұрын

Maybe offtopic, but i'm pretty sure cc cleaner never ever really solved a problem. It's just snakeoil ;)

@8bitfrenzy376

5 жыл бұрын

@@wanjaschonecke455 It can reset the registry, it's actually useful

@andrewallen9993

5 жыл бұрын

@@asbestosfibers1325 Yeah, I actually used to change the air filters as well as the oil and oil filters in these machines. Whereas you have not the faintest idea what you are talking about :)

@andrewallen9993

5 жыл бұрын

@@8bitfrenzy376 You could change any of the registers from the front panel of these.

I had never considered, just how much ‘mechanical’ goes into the more modern computational rigs. And more recently even, it is not at all apparent until you try to change your ink cartridge, or even more applicable is storage devices. Mechanical engineering really is a precursor in all things electronic, to where we’d be nowhere if it weren’t for our ability to predict the mechanical implications of anything. SO AWESOME!! You know what you’re doing is important when the World wants you to film every minute of it!!

On your fingers, no nail Polish. I really respect that. Thank you.

I never knew that they used clutches for the reels! Suddenly the abrupt motion makes perfect sense!

Wow! When computers were real MACHINES! Thanks for sharing!

13:20 the speed of that typewriter is fucking unbelievable, hats off to the engineers and maintainers of this tech. I had no idea the technology was that fast before the digital revolution.

@ZTenski

3 жыл бұрын

Just out of curiosity, I wonder what the throughput rate of such a machine is, in terms of bytes.

Wow, computers of this era really were *machines*. A computer system running with v-belts and clutches!

Can't get replacement parts? No problem, we'll just go to the shop and make our own, BETTER than the originals! I LOVE watching you all do that! Another great vid! Thumbs up!

Worked on similar units to these as late as the 80's in the Air Force. They used them to load programs onto a CENPAC unit and run automated test stations for maintenance on F-111s.

those connectors were epic

@izzyfromoregonoregon9654

6 жыл бұрын

Tom P. They look like from the 1800s

@simontay4851

6 жыл бұрын

Now _they_ are proper connectors! They will last forever.

@incog99skd11

4 жыл бұрын

The old bus and tag. I remember when we replaced those connectors with fiber. During the next big earthquake in California, the cables did not hold the disk drives in place anymore. They flew around the room as a result causing great damage. After that experience they had to retrofit special feet on the disk drives to keep them from flying around. Who woulda thunk that a fiber cable wouldn't secure those big drives to the floor anymore!!

As a mid 90s child that used VHS tapes, seeing that fast rewind is curiously satisfying.

Thank you for uploading. I did not know 6 years. I used to use these machines in a "IBM machine room" in from 1986 to 1989 or so for me. The punch card machine is the same model. The tape machine is somewhat new model but the vacuume loading and driving mechanism is totally the same as this 1959 tape machine. Punch card machine used to run the daily batch job cards which were really bundled with rubber. and the tapes were used for daily backups out from that daily batches. If the data failure, they used for restoring the data. Still in late 1980s, they were the real and workable machines for several Japanese factories and banks or so, especially large enterprises using computer from 1960s, 70s . However I have not seen the inside at all. So this video is so valuable for me. Really great. Thanks again.

Machines from when I was a young man. Good show on why those things were so expensive. Well done.

Brings back memories! I was a field engineer with Burroughs in the late 70's / early 80's, and we had rather similar units. A bit more sophisticated electronics and motors, higher speeds, but the same basic principle. Many 'fond' memories of trouble-shooting those beasts!... Ahh, the good old days...

Techmoan's PC.

@TexasRailfan2008

4 жыл бұрын

Silver Spoon yes...

In 1974 I was programming an IBM 1401, GE 225 with drum memory. In 1975 I moved to a IBM 370-135 DOS machine these were all in college. I graduated in 1977 went to work for the USAF doing systems development on a IBM 7080 and a CDC Cyber 170 running SCOPE. There just nothing like the smell of a hot IBM 24 and 80 column cards at 03:00 in the morning

Wonderful to see familiar old technology. "When computers looked liked computers!" and you could immediately SEE that they were working properly.

The glory days of IT. I miss them....

The red shirted working hands look to be of same age as 1401, marvellous video..

I used to work with Teac and HP mag tape units from the 80s / 90s on Ericsson AXE10, IOG3 & IOG11, not as impressive as those units, but still rose tinted memories. That's for posting the video.

Thanks for sharing this video. I worked on these systems (IBM 370) in the mid 1980's. I was an Operations Support Analyst.

I never knew they sounded like that while reading and writing the tape! I knew these computers would be complex, but geez, the electronics in there are a marvel in itself.

The little black plastic rollers that push the tape against the capstan to move or against fixed round rubber cylinders to stop are called prolays, one on either side.

How many still watch such video?? this one is awesome. thanks for the details...........you folks make thing work out interesting for us!! kudos!!

What an amazing insight how these tapes actually work...

I used drives similar to these in which the window in front of the tapes would lower for unloading and loading. We used to place the tape volumes of multi-tape master files on control box at the top of the drive. Later, the company bought STC drives, and the windows on those would raise up through the control box. It didn't take long to learn to put the to-be-used master volumes in a separate (and inconvenient) rack. So many memories seeing that printer and the 1401 control panel!

This amazing machine was in operation even before robots were saying "Danger, Will Robinson!"

Someone should write a simulation of this and expose it as a block device to the kernel then write an OpenGL visualisation app that can show tape reel position and how much is sucked into the virtual vacuum tubes and how fast it's spinning and stuff. Then you could make a filesystem on it and copy stuff around and watch the reels spinning as it did its thing :D

2 years ago, I made a two brushes, using with knife for common electric drive. I lost something about 5 hours on this job, but motor is working everytime! Greetings from Russia, and thanks a lot for these awesome unicue video, Author! These videos must watching in schools :) Oh my God, sorry for my English

These machines and these men are why America became Great. Make America Great Again.

This is the exact kind of video needed 10 stars Marc! You have generated all kinds of hope..........

This is why I love vintage computers, you have to be not only an electrical engineer, but a mechanic too!

This was soo cool to watch all the way to the end. What a great demo of the tape drive that is soo cool that you got it repaired! Thank you soo much for sharing! I remember seeing these in action when I was a kid. I have a friend long been retired now that worked with these in a meat processing plant. I remember seeing them run at IBP in Dakota City. I remember my Dad as a clerk at the railroad used punch cards to keep track of train cars at Chicago Northwestern RR.

Theres a few electronics inside of it....."opens it" HOLY JESUS

@snaplash

6 жыл бұрын

No integrated circuits then. All transistors, diodes, resistors.

@jamesplotkin4674

5 жыл бұрын

@@snaplash And a ton of relays!

@furrywithacomputer9824

4 жыл бұрын

Looks like a nightmare to fix if something went wrong

@simontay4851

3 жыл бұрын

Yeah, just a "bit"... understatement of the century.

@GerbilNoises

3 жыл бұрын

@@simontay4851 it's been a bit

Love those tape drives, they are as much mechanical as they are electronic. I remember seeing them as a kid in the early 80's and thinking how awesome they looked.

I remember seeing that card sorter back in 1965 ... it was cutting edge in those days :)

Awesome job guys! I'm sure no serious company on earth can reproduced the quality of these monsters now days! (And nobody can have your talent and passion about these pieces of history) The great "electromechanic" era. hope to see a Silicon Graphics or Intergraph wokstation on your channel! Best regards from France.

There’s something deeply satisfying about actually fixing these old things instead of just letting them collect dust all broken down 🖖

I think it is interesting that the lathe used to make the brushes has more processing power than the 1401

I always wondered why the units were so big compared to the size of the tape reel - very interesting!

Amazing, i didn't knew how complex the tape unit was, fantastic, thank you for sharing this.

This is one of the coolest things, I am really happy someone appreciates the antiques enough to keep them running. It's like a classic car.

MANY THANKS for putting this on. Ever since I was at school in the 1960's I've wanted to know how these tape drives work. You've certainly made an older man very happy.

It's really fascinating to see how these drives work. Being shown the inner workings it all makes good mechanical sense - I had always vaguely wondered what sort of mechanisms were used to drive the reels and control the recoil of the tape. Never would I have imagined that there was a vacuum channel employed there!

Seeing this operate in 2016 makes me eager to see it in action.

There are still naval warships using tape drives. When I retired in 2014, the FFG-7 Class guided-missile frigates and some US Coast Guard gun-armed ships were transitioning over to CDs, but some, especially several foreign FFG-7s in nations with fewer funds for conversions and upgrades, were still using them. The tape drives are not IBM, but made by Sperry UNIVAC, all to "Mil-Spec" and MUCH more solid and heavy than the IBM drives you show here (half-inch steel frames and eighth-in steel cases, with heavy lock clamps around the doors to keep out water, etc.). The older drives, UNIVAC 1540s, were somewhat similar to the 1401 drives, but instead of a vacuum tape reserve buffer in two long tubes, they had a series of spring-loaded short arms with rollers at their tips. When you put tape through the machine from the source reel to the take-up reel, you threaded your tape through a narrow gap across all of those rollers, through the read/write head block, through another set of cushion arms, and onto the take-up reel, hand rotating everything to be tight. Then you hand-rotated the source reel forward a few turns (not quite to the LOAD POINT silver tape mark) to make sure it was secure on the take-up reel. This caused the two sets of arms to spread apart forming a pair of "W"s of tape, each arm of the W about a foot long, one on each side of the read/write block. You made sure the tape was not loose anywhere and then turned on the power. The arms suddenly spread apart even more and tightly held the tape and each arm could pivot under spring loading at its base, allowing more or less tape in the interval between the two reels, as needed, this being the cushion for fast tape motion that those two vacuum tubes do on your IBM drives. All loading was manual, including running the tape past the LOAD POINT silver tape mark and then manually pressing LOAD to cause the machine to move the tape forward and then backward to the LOAD POINT to be ready to run. Later, the UNIVAC 1840 drives appeared to slowly replace many, but not all, of the 1540s. These used a vacuum tube system like your IBM drives do, but not visible unless you opened up protective steel doors on the drive face, and were automatic: All you had to do was put the source tape on its reel shaft, lock it, and then feed the end of the tape into a small slot in the central read/write block, which was much bigger than used with a 1540. When you hit LOAD, the tape was sucked into that slot, the tape ran onto the take-up reel, the vacuum cushion inside turned on, and the tape was then positioned at the LOAD POINT silver tape mark ready to run. I assume that inside all of these machines, they were just as, if not more so, complex as yours are.

Fascinating and awesome! a 20 MB tape from 1959. I don't feel quite so old thinking back to my first 20 MB hard drive. Ehhh actually I still feel old. ;-)

For the carbon brush flexible wire, you could have used Solder Wick as wire.

Thank you so much for your time and effort on both making these videos and keeping these amazing machines in working order. I very much look forward to your next video.

In hindsight it always seemed amusing that Gerry Anderson thought we'd still have these dinosaur computers with whirling tapes at the end of the century in Space 1999! Star trek were way ahead of their time though with voice responsive talking computers, although at least originally they were monotone; unnecessary except perhaps to distinguish them as computers. Even so I have admiration for the clever designers of these fascinating machines.Thanks for showing us.Brill!

What a wonderful look into the past. Hard to imagine how far we've come since then being it wasn't that long ago.

Maximum respect to you guys for your time and dedication to keeping these amazing machines going. The random movement of the reels on these drives has always fascinated me. Thanks for sharing this. I worked for DEC many years ago, though I'm not sure they produced a vacuum column drive. Maybe you know....? All the best !!

@jonathanoxlade4252

7 жыл бұрын

these machines are built like steam trains they will last for years to the earth dies while modern computers will last 5 years and die due to the life cycle of silicone and transistors and the caps on the boards

I envy you, Americans, simply for having museums about old computers and getting to see them in action. We, în Europe, especially Romania where I live, do not have that opportunity. It would be a dream come true for me to see an 1959 computer fully operational

@99domini99

8 жыл бұрын

We just put them down here. Even if they function fine, they're just tossed down for people to look at. Sad that they have to die like that.

@HunterShows

4 жыл бұрын

Don't misunderstand. There's almost nothing like this in the world. There is *a*. museum for old computers. There are obviously displays elsewhere in science museums but I have never heard of any other computer museum.

I love that part where he said "we open it and there are some electronics in here" and its a cabinet full of boards

The enginerring complexity of that time to accomplish something so simple we take for granted today is amazing. IBM hired the best.

Awesome video, it gives "Mechanical drive" a new meaning. Thanks for uploading it. Wow 20MB that must have been like 20TB back in the day, given most programs used a few KB.. I just subbed to your channel:D

Thank you for the great video! These tape drives are what got me interested in computing originally and I miss them a lot. You all have some of the best jobs I can imagine!

Thanks for this video! I ran across it while doing some research into the function of these tape drives. Also thanks to the IBM 1401 team for the documentation on your website. The 729 CE Manual found there is newer and more informative than the version on bitsavers. It was quite interesting to see the repair of the clutch brushes. It makes me curious about how other maintenance items are handled. There's a lot of old technology there that's going to need occasional repairs.

The most interesting video I've seen in a while!! I love when people keep cool old machinery like this running.

Was fascinated watching these guys work on this stuff we have come such a long way

Brilliant work! Few things are as cool to watch as those old tape drives. Thanks for sharing a peek at the inner workings!

I could watch that all day, everyday. Great work guys.