Now just wait for HP 4951C copy protection to turn out to be just the machine being shy and not wanting to execute an app while everyone's staring at it

@dan3a

4 ай бұрын

At least it's not like my 4951B which violently ate a tape lol.

@tocaamerillo431

4 ай бұрын

I saw someone make a suggestion to try and format, write image and read the disk with the same physical drive for the copy protection trick and that might not look so ridiculous now

@Thiesi

4 ай бұрын

You have a point there! I mean we all know _eDonkey_ - a software I have never even heard of and which I've _definitely_ never used - was not picking up speed when you were watching it, but the moment you closed your eyes to take a little nap, your entire download list would complete in an instant.

@scotrick3072

4 ай бұрын

I used to run tech support for a very very small (15 machines or so) mac lab in a university English Dpt, and while I worked mainly with the macs, across the hall were Windows machines, and all of them? All of the computers could smell fear in a student and would refuse to work for them, in small annoying ways. They would call me over, and then the machine would work. They were all like pets, refusing to act for people who weren't the 'owner.' I know, absolutely and totally, that this is nuts. But I also know that many computer errors are caused by neutrinos sleeting through space, so, whatever. Shy? Totally. Well, maybe. Also? Perhaps a bit of a prankster.

@Toonrick12

4 ай бұрын

Ah, doing a Michigan J Frog.

Tip if you want to glue a belt: - Cut it at an angle giving it a larger area and you are not pulling directly at the join. - To cut lay both ends overlapping and cut straight through both at the same time - this ensures that both ends are cut at the exactly same angle.

About gluing together rubber belts with superglue. 1. cut faces as straight as possible with a knife (no scissors!) 2. Only apply glue to the cut faces. Use a needle to apply the glue 3. Press the faces of the cuts together. The best way is to pinch the ends with your thumb and forefinger nails as close to the cuts as possible and press them together. 4. Hold the together for at least 10 seconds without moving. 5. Peel your finger of the belt carefully and wait at lest 15 minutes before proceeding. 6. Use fine sandpaper to remove the glue residue from the belt. use the belt. The less glue you apply the easer is the clean-up afterward.

@g4z-kb7ct

4 ай бұрын

You can't use superglue to join a belt. You need to use a glue that doesn't dry hard and stays flexible like rubber cement / contact adhesive.

@Tomppa8.2

4 ай бұрын

I have done it and it works just fine. Granted i dont use the machine often. I cut the belt diagonally so the glue joint is longer and stronger.

@Dutchreason

4 ай бұрын

You guys are probably right... Having worked extensively on electronics from the 1920's to the present day... nothing beats regular elastic bands as "proof of concept".

@dabigbadwolf5081

4 ай бұрын

Why don't you just vulcanise the rubber?

@boelwerkr

4 ай бұрын

@@dabigbadwolf5081 Because it's not a "just" process. You need the right rubber to do it. Try to glue your average rubber band this way and you will see that only around 30% will actually work. It all depends on the composition and if the vulcanizer is able to loosen the bonds in the rubber well enough to make the faces stick permanently. Superglue connects the pieces by clinging to the irregularities of the glued faces and it holds on to the faces by a purely physically process. You can glue all kinds of materials this way.

You got to vulcanize the rubber, it is different chemestry. Contact cement would work. Also, cut at an angle.

The "Shugart style" addressing is the correct way of addressing these floppy drives. The IBM PC just uses a hack to enable drives to be swapped out without re-addressing them, by assuming that all drives have address 1 (DS1), and the wires for drive A and B are just flipped around on the second connector in the cable. In the correct situation the drive would handle that by listening to the different drive pins.

@BlackEpyon

4 ай бұрын

The only reason I learned about "Shugart style" floppy drives is because I've got a couple Tandy 1000s, and they used Shugart pinouts all the way to the end of the line with the RSX. To make it even happier, the keyway (on the 3.5" drives) is on the opposite side of the connector, AND some of them even ran power over the ribbon. Put the two together, and you can end up with some very not-so-happy results if you have to replace a floppy drive and don't pay very close attention to the pinouts. It's also why I like to hold onto 3.5" floppy drives that have switches or jumpers on the back, 'cause then I don't have to worry about modding the cable.

I can't believe this! I didn't think I would ever see one of these alive and working again. The only person who had one of these back in the day was the president's secretary where I worked in the 80's and 90's. She made that thing sing and dance. Eventually other secretaries were given pc's running a word processor app networked to a laser printer. The Xerox was retired when the secretary saw how much easier the word processing combo was.

@DandyDon1

Ай бұрын

Imagine if she had been exposed to the Xerox Star 8010, 6085-1 or 6085-2. Those ran circles around any other Word Processing software. You could also do graphics too!

Thanks for this series! I left Xerox in '97 and had a 645s of my own. It was borrowed from a pile of stuff after Xrx discontinued selling them and they told me to just keep it. I held onto it for a couple of years but it took up space so I sold it on some user BB, think I got like $300 for it, including a bunch of disks, wheels, and ribbons. Anyhoo I'm thoroughly enjoying your resurrection videos and while I'm not so much of a techie your explanations are great so I'm getting it. It's fun for me too because I helped to sell those things as well as other less capable models of the Memorywriter line. It's also fun to see, and to hear all those noises that I had become so used to back then. I was also a proud owner of their 820-II cp/m OS PC, which also had dual Shugart 5.25" drives and a Diablo 620 daisywheel printer, basically the same thing as what's in the 645.

I'm wondering, isn't there a pot to adjust the motor speed? Belt driven drives usually have it.

For speed issues you also need to factor the belt thickness, not just the length and width. The thicker the belt the faster things run as the arc around the pulley is actually the mid-point of the belt thickness (the outer rubber stretches, the inner compresses). The thinner the belt the slower it runs as the arc is effectively lower/smaller. On high-speed systems this is certainly significant. I tried making this point a few minutes ago, but I think my post was deleted due to a link to ‘Turntable Basics’, where if you hunt around a bit you can find belts of pretty much any length, width and thickness.

A janky solution for using a longer belt would be to add another idler pulley (or move the existing one to a new hole).

Hot dayum, I thought I would have to wait for this video for a year at least!

Please keep on this project. I am trying to find one of these machines and restore it for personal use as well. This series has been absolutely comically mind boggling for me! Your understanding of this technology is miles above my own

I worked for Xerox in 1983/84 and the Memorywriters were one of the products I was trained to repair. Unfortunately I don't remember much about them and didn't retain any training materials. I do remember a particular customers machine that I literally replaced every module/board etc. and it had the same problem. If I recall, the customers had some funky wiring problem with their power that caused it.

I was thinking you had already ruled out the gotek during the last video. Glad to see it work!

McMaster Carr has buna n tape (flat stuff) and buna n string (standard o-ring stuff). If you also search for buna n splice kit you'll get a selection of glues and tools that help you cut, hold, and glue the buna n together. Edit: Also Grainger.

Why isn't this on the main channel right next to the previous video? Almost missed it.

HA!!! reminds me so much of one problem i encountered. So a little context im a heavy equipment tech, been doing it all my life and im vary confident in my abilities. Buddy of mine asked to me look at his ride on lawn mower, just stopped moving and wouldn't go anymore. I spend days diagnosing this thing had it pulled apart all the way down to the hydro static transmission. Well... all along it was just a sheer pin in the tire hub... 5 minute fix, but i was so convinced it had to be something else i totally neglected to even consider checking the basics.

An elastic belt with too much tension causes a speed difference in turntables, I guess this could be the same. (If I remember correctly the compression of the belt at the capstan causes this... and somehow creates a different gearing.)

@AnnaVannieuwenhuyse

4 ай бұрын

The compression from the stretched belt also very slightly deflects a lot of mechanical parts

This is just amazing stuff. Love to see it. Have been interested in typewriters and word processors since grade school and recently picked up a 90s Brother WP and the floppy drive was dead so I swapped it for a gotek and now it works great.

Its videos like these that make me appreciate you so much. Very authentic of you to show the side of yourself that all of us see of ourselves constantly!

It makes sense that formatting would be troublesome as there are no sector pulses to synchronize the spindle so it has to guesstimate Reading data and writing data is much easier because of the constant feedback from the disk structures (sector marks). You would likely have much more success with wonky timing on a hard sector drive.

Congrats, Shelby! It's always the last thing you try! 🤣

The speed thing should not be an issue. Use the new belt. Measure the rpm and re-calibrate the speed of the spindle so it's set to whatever the machine expects. There will be a way to adjust it, either by turning the motor or an adjustment potentiometer.

Just when I think I can’t become more boring about any given retro technology I discover this gem of a video.

thumbs up for desk butt. One who hasn't been there, has never tried.

3:15 keyframe drop 😆 scrunchy face

7:40 the moment you KNOW it works! Shelby, I've been holding out on you...I actually have 4 or 5 of these, with monitors! I had them for about a year, and didn't see your series on restoring these until recently...yet more excellent content, that now will be educational material for me...nicely done!!! OH, and one of the factory Xerox disks was left in one of the drives! So, on your disks, are you sharing your flux-level captures on archive or anywhere that we could access them? I can eventually compare what your machine uses with what I have, and see if there are any differences...always fun stuff!

@techtangentsii

3 ай бұрын

The system disks I'm using I have put up as flux here: archive.org/details/xerox-memory-writer-645-640-base-0 I don't have the binary images on there yet (those were made before I had fully learned how to do that). Also on my account there I've uploaded the manual and ROMs for the machine.

@ForgottenMachines

3 ай бұрын

@@techtangentsii Most excellent, thank you!!! I see you even have the flux level files in there (from a Kryoflux!), which is exactly what I was hoping to see, most excellent!

I can relate to how you feel, I feel like this all too often myself

If you want to make custom belts, use rubber cement, and very thin cotton fabric on the back side. Superglue is a bad choice because of it's rigidity.

There are already some messages suggesting improved glue operations. Here comes a couple more. Besides cutting at an angle (lengthening the glue joint), you could make the ends wedges in thickness direction, increasing the joint area. But one other advice I got years ago, regarding O-rings: You needed to prepare the two surface by “cleaning” them with a short dip to sulphuric acid. I have never tried it, but the advice came from a rubber chemist, so I tend to believe it. And the final one was that you could after the sulphuric acid treatment use as well epoxy as cyanoacrylate adhesive. My own recent experience is using the new UV curing adhesives, either epoxy or cyanoacrylate (super glue). The curing speed is amazing!

@g4z-kb7ct

4 ай бұрын

Using acid is a bit extreme. I used to fix rubber items 30 years ago and I just roughed up the surface with some sandpaper and the glue bonded perfectly. You need to use a glue that stays flexible, superglue and epoxy are no good. Use contact adhesive.

Congratulations!

I’m thinking of a fix 😊so get 2 metal nails and piece of wood Guess the distance between the nails to suit the belt circumference that you need Stretch the belt over the nails And heat with hot air Might work No melting

Well done!!

Is there 3d printer filament you can print a belt with?

An inch can make all the difference

You sure it's the belt? RPM of that flywheel can be measured precisely with some tape and a photoresistor or something, since you have a 'scope. It can be compared to the good drive.

You can try to take out plastic pulley roller to release some tension on 10 inch belt.

check drive speed, head alignment, track zero sensor, capacitors on the logic board and head drive transistors if it has them.

Like the Xerox 860ips I believe it uses the floppy diskette as "scratch pad" until you save the file. You could always tell when the 8" Shugart drives of a Xerox 860ips were dirty. The appearance of text on the screen as you typed would be delayed. Stupid question I know.... PRB Line doesn't have a belt that will fit?

Also needs to be a fabric impregnated blet the rubber with make the disks speed wabble

I seem to remember that the Apple II disk II format (DOS 3.3) is 16 sector format with 35 tracks however you could force it to 40 tracks. With the directory on track 16.

If you want to try cutting a longer belt and joining it use the same method and technology that is used for splicing video cassette tapes.

Nice video!

@FozzTexx 3D prints belts with much success. It worked with his Commodore PET drives! Maybe give that a shot if you have a printer and the correct materials.

5:43 "Ohmygosh am I an idiot‽" NO.

While you're waiting to see if you can find an 11" belt you could also stretch the 10" over a object with smooth corners and see if it relaxes a bit over time. You only need about 10% stretch. No idea what exactly that 10" belt composition is but maybe worth a shot.

What about measuring the belt from the working drive ?

i recently had the same issue with a Toshiba T1910CS laptop, the belt was completely destroyed the only had belts I had were too tight or too loose, I ended up cutting one and gluing it like u but using as little glue as possible and it was impossible to get it just right (i gave it 3 attempts before giving up), so I need to buy a belt and the only seller on ebay that sells these is away on vacation until the 31st (doesn't sound like much time but i've been waiting almost a month now lol), really hope it's just the belt tho, these things are so annoying, im so glad we moved to direct motor like right after this laptop was launched (tho kinda wish we moved onto direct motor designs before this laptop was out, would save me 10€ rn 💀)

At 9:50 in the video, when you are showing off the belt in the drive Is the center pulley functional, or is it just there to provide tension to the belt? Cause if it's just there to provide tension, you could try to just remove it. ...But it looks like it might be there to stop the belt from rubbing against the stepper motor, so _welp_

Could you stretch the 10inch belt to 12inch? I mean by heating it, or overstretching e.t.c?

@g4z-kb7ct

4 ай бұрын

No. If you heat the belt it will become hard, melt and permanently damage it

5:46 We've all been there...

So where can you get replacement floppy drive belts from these days ?

I guess, if the tolerances for formatting are smaller than for read and write, this may imply that there are timing pulses recorded to the disk and that read and write operations somehow adjust to these sync marks. Which may explain why read and write work perfectly, but formatting fails as the drives can't establish a precise timing reference.

Question: if you use a semi flexable material like TPU, is it possible to 3d print a drive belt for this?

@GGigabiteM

4 ай бұрын

You can print belts out of TPU, but for fine fiddly stuff like this, you'd probably need a small nozzle and really short layer heights. I only have printed a few belts, but I recommend using the "staggered endpoints" option to keep the layer endpoints randomized and avoid a clump in one area that you have to sand down later, and potentially be a weak point in the belt.

Looks like someone is eating crow for dinner lol

ive been wondering, what do you use to mount your DSLR on the mic arm? i cannot find anything when i look for a hot shoe mount and it is something i wanted myself for filming on the desk for ages

@AnnaVannieuwenhuyse

4 ай бұрын

The end of the mic arm has a threaded section that can be connected to any kind of camera gear coupler that has the right thread; these are often either 5/8ths or 1/4th inch size. You can choose to use or omit the ball joint he's using.

@Space_Reptile

4 ай бұрын

@@AnnaVannieuwenhuyse oh i somehow didnt think of that, sadly my mic arm thread is not 5/8ths or 1/4ths so i have to go and look for one

SUCCESS 👹

I can't remember. Did the later floppy controllers allow the use of d0-3 and or 4 with a striaght ribbon cable? I know later on that was what the twist was for.

@Stoney3K

4 ай бұрын

If you mean in the IBM PC, that was never supported. All PC floppys should have been jumpered with DS1 and the twist will flip around ALL related pins so drive A will appear as 'drive A' (which uses a non-standard way of selecting the drive) while drive B uses the proper pins for DS1. The Shugart standard was to have all drives on the same ribbon and just use a bunch of selection bits to enable the drive you want. IBM probably wanted to have all drives manufactured the same and not have the user mess around with jumpers.

@idahofur

4 ай бұрын

yea the ibm pc. To long ago. I do remember an isa card that supported 4 drives.But, I want to say it had 2 floppy connectors. 2 drives on one cable and two on the two on the other. Like the new repro card. @@Stoney3K

When you lifted the KB at around :30, what is that rectangular box attached to the KB? Sorry if I missed it in a previous video.

@bobbymelbourne4502

4 ай бұрын

It’s a addon spell checker

lol it's great to see that it works

Now I'm confused as to why they even sold pre-formatted floppy disks, if they weren't like... "hard" sectored (pre-baked at least) after all... I liked how that belt-shortening was reminiscent of tape-splicing! Especially with the kapton tape stuck on there.

@TrimeshSZ

4 ай бұрын

It's a historical thing - on a soft-sectored floppy the track format uses some special patterns of flux transitions you can't write as regular data (called "address marks") - some early controllers were not capable of writing them at all, and hence the disks needed to be pre-formatted. Later FDCs were typically capable of full-track formatting, but there were enough old machines around that people still needed formatted disks.

Did you tried to boil the old belt??

While not as good as properly made belt wouldn't 3D printed TPU belt work, at least for testing?

What about, to add another puley for the longer belt? 😉

RIP TT's sanity

@sanityormadness

4 ай бұрын

There was some madness in this stream, yes.

3d print some belts in tpu?

This might be dumb but what if you took the belt that is too short and boiled it and then stretched it? Probably wouldn't last but it might work temporarily.

Omniflop can format custom formats disks

Now the important question is, can we play doom on it?

Are you sure it’s the belts? Seems like you can read but not write; could it be the write head or associated circuitry?

@sanityormadness

4 ай бұрын

TECHNICALLY, it actually wrote. The flux images of the results were.... interesting, to say the least, bearing very little resemblance to the "good" drive. (I'm actually surprised that didn't make it into this edit)

Can you not stretch the belt a bit? Hmmm...m

Glad you got it working - but have to wonder - who was buying these things in the mid-80s? The seem to be the worst of both worlds. Perhaps it was cheap - but being Xerox, I somehow doubt it.

@markdecker6190

4 ай бұрын

One of Xerox's sales techniques, and I'm sure others were doing similar, was to give the customer a "free" Memorywriter if they bought enough bigger copiers. They also did that with fax machines or smaller copiers. When larger corporations spent enough money and bought enough gear they might have gotten multiple free machines. It was kind of like the puppy dog close because if you liked it then you would probably want to order more of them, not to mention the ongoing purchases of supplies and service contracts.

lol doh

try using a rubber band

Does this run DOOM?

@Toonrick12

4 ай бұрын

It could, but unlikely.

Use glue used to fix bicycle inner tubes to glue the belt.