I was an Atari authorized warranty technician for 10 years (1985-1995) in Federal Way WA. The local school districts would send me all their Atari disk drives for service every summer, hundreds of drives, plus many hundreds off the street. Some things came to mind as watched this video. The early 810 drive (MPI mechs) came with no separate FDC daughter board, but it was found that the built in 1771 data separator was defective and so that outboard data separator daughter board was created. Spindle bearings can get grabby and this can cause issues. The PLL can't stay locked to the data clock when the disk speed momentarily dives. The disk head needs to be thoroughly cleaned. You can't just look at the head and say, "oh it looks clean" as the interfering filth is microscopic. As you saw, the analog board has no shielding and so strong magnetic fields from monitor yokes did cause problems, even though the head signals are differential. Your problem drive probably needs a new pressure (compliance) pad, after another thorough head cleaning with a cotton tipped swab (not the cleaning disk). The felt pads wear and stop pushing the disk evenly down onto the R/W gap. Some pads used an adhesive like rubber cement and could easily be damaged by bad disks or improper insertion / removal. Alcohol can soften the adhesive and the pad becomes misaligned or gets rolled up. Use a mirror to inspect the pad. Nearly all the pads on single sided drives of this vintage are going to be defective. One other thing comes to mind. The connectors and their pins often have fractured solder joints. Check the joints under a microscope or touch them all up to correct the fractured solder joints. On that old software for the 400/800, you'll need to load the "translator disk" to get the old software to run properly on the XL / XE machines. The MPI and 1050 drives had no adjustments for head azimuth, but the TM100 mechs did have an azimuth adjustment that needed to be performed using a scope with the alignment disk.

I gotta say.... those are some good looking drives!

Awesome that you're using the FujiNet, I'm one of the devs on the project. If you want to boot your disk from FujiNet with Basic disabled, hold the option key down when booting until you see the Blue Screen boot, otherwise Basic is left enabled. Same way you do when booting Gorf, as it's an Atari thing, not a FujiNet thing :D If you just "tap" the Option key, basic is still enabled, which can be a problem for some disks/applications. Happy FujiNet'ing!

12:21 , as someone that worked in an injection moulding factory, yeah moulds are incredibly expensive, upwards of $100,000 so that's a major cost saver

To answer your formatting question: The FORMAT command itself in the drive firmware is expected to format the disk, then verify it, while returning the number of bad sectors it finds. If this number is 0 (and the command acknowledges as COMPLETE), then the disk utility package will write a filesystem to it. Otherwise, it will return the # of bad sectors, the disk utility package will re-issue the FORMAT command again. If this fails again, then an ERROR 173 (bad disk format) will be issued.

Atari was selling so many VCS game consoles, that they had an unbelievable quantity of 6507 and 6532s in their parts store, and were getting them for vastly discounted prices. It was heavily incentivized for engineers to build peripherals using those two chips.

Makes me miss my 1200XL. I spent so many hours punching in code from old Computer Games magazines and saving it on cassettes. At least until I finally got a disk drive for it. Seeing these things just lights up all kinds of old memories.

The top and bottom of the 810 are indeed the same, and was one of the nice touches that Kevin McKinsey made to make this thing easier to produce.

In early 1982, Atari made a deal with Tandon. Atari would buy TM100-1's in large quantity to fulfill the 810 orders, and Tandon would design the replacement disk drive for the 1000 series (which became the XL systems), the 1050 (which used a Tandon TM50-1 mech).

Adrian needs the well known Translator disk for 800 to 800XL compatibility.

The early 810s like the one in the middle, use the mech from Magnetic Peripherals Inc. (MPI aka Control Data). The later 810s use a single sided mech from Tandon (basically a TM100-1 without its analog board) Original 810s had no data seperator (completely disregarding WD's technical note on the 1771 stating that data seperators were strongly encouraged), which lead to companies like Percom selling Data seperator boards. Later 810s had the Grass Valley modification, which included an improved analog board, an improved motor control board, and an improved ROM which changed the sector interleave to improve performance. The Atari disk drives also have a particular quirk that they are tach'd at 288 RPM, rather than 300 RPM. Also, thanks for the shout-out on the FujiNet :) -Thom from FujiNet

The addon board was a fix released fairly early in the 810's life - the drive will work if you plug the 1771 straight into the socket but it'll be more prone to read errors. Also they used CPUs rejected from the 2600; the console ran the 6507 slightly overclocked, and any that failed to cope eventually ended up being repurposed. Also as a heads up, GORF and EP-CYG-4 are incompatible with XL/XE machines.

Fun fact, the creator of the SIO interface used it as a basis for creating USB.

I'm a Commodore guy but it's nice to see some different stuff. By the way these long videos are great and i love them !

That "mod board" is the external data separator in the FDC socket. That was an "optional" thing with FDC chips that turned out to not really be so optional after all. And the CPU ("maybe that's the ROM") is the same 6507 as used in the Atari 2600. The 6532 RIOT is another of the three main chips from the Atari 2600. And yes, both chips are relatively common as long as there are junk 2600s to steal them from. The interesting thing about the 1771 chip is that apparently it's an inverted-logic bus version. So all the sector data on the floppy is inverted! Way back in '08 or so I was ripping all sorts of disks with a Catweasel board (PCI version in a Linux system) and found that you have to invert all the sector data when reading Atari disks. There's also the issue of the slightly slower motor speed which gave them one extra sector per track.

Ah! (paused at 23:08 so if you cover this, sorry)... the CPU in the first drive is a Rockwell C010745, a 6507 made by Synertek. It looks to be a MOS 6502 type CPU with only 13 address lines and some other pins dropped to fit a 28 pin DIP. So it only works to 8Kb (the Hitachi chip is RAM), and the GI 9316B chip is mask ROM.

The 810 can be upgraded to true double density with a Happy board, which replaced the 6507 with a 6502. Faster SIO too.

I'm glad to see the Atari get some love. It just occurred to me that I didn't get any ads. Did you forget to monetize? Also, we were supposed to have a test today, teacher.

As someone who grew up with a 130XE in the house, happy to see the Atari 8-bit line getting more love. The 1050 was my daily drive(r) (huhuhuh) and the one we got for our machine kept having read issues and went in for warranty service multiple times at the local dealer. That wasn't common though I don't think. I just acquired a 130XE that's in mint condition, save a non-working Start key but i picked up a FujiNet and can't wait to mess around with it once I fix the keyboard.

The production of your videos has really stepped up Adrian! Ive been following you since the early years. Awesome !

Great video. My knowledge of the Atari drives is pretty limited - it's great to learn about them.

you are magician :-) ... my dad entire life repaired tape/cassete recorders, lots of mechanics, belts, heads, etc .. this was very close :-)

31:00 I have seen those printouts from test equipment before, gear from APC usually came with validation results, but nowadays it is as rare as finding a paper schematic inside electronic equipment, you have to buy some really expensive stuff to get that kind of respect for the customer today.

The Atari Drives are similar tot he Commodore drives as in they are intelligent devices under a CPU Control. But as you seen there are differences. I used to work on them for almost over 15 years for the NYC School District 3 and surrounding community centers as they had various 8bit computers for their students and clients to use. As for the flakey drive, De-Oxit the rails. Its a Brass Bushing on the head sliding mechanism is sliding on a stainless steel bar; the lead from the Brass and Iron from the Steel will react with each other slightly, causing it to be 'sticky.' De-Oxit should clean this up. Then WD-40 to wipe and and clean it up and put some lube on the rails, what ever lube you like to use. Then drop a couple drops of oil into the shaft of the head motor to free it up. And that should fix that drive. It is rare for the head cable to fail or its connector to fail. Do the same with the other drives as preventative maintenance. When you formatted the disck, that freed up the rails a bit and got the drive working again. But puting that moldy disk into the drive mucked things up again. As I remember, sector size was 128 or 256 bytes per sector, the same as on the cassette drive. And formatted similarly to the Commodore Drive with track and sector info on the sector. Though the Atari 400/800 came out in 1979, it was already in the ending of the prototyping stages in 1977. Bush Nolan did not have the money to release it back them and when he sold Atari to Warner Communications is when he was able to release the 400/800 as planned though 2 years after the Trinity was released. So image how different things would have been if the Atari 400/800 came out with the Trinity! But instead he released the 2600 to make his money in the game industry. Good for him as he did well with that.

Hi Adrian, nice to see you tackle FDD servicing given your general stance on these. Brought back memories of doing same in the resurrection of a C64-SX - At least the belts seem to still be good on those 810s. - Hopefully the notes here in the comments kindly provided by a couple of people who serviced these units back in the day will get that flaky 810 back online! - P.S.: Finding that these Atari FDDs were actually more expensive than Apple's units at release cracked me up 🤣- With half the storage capacity, at that! 80K - That's the same or less than the Spectrum microdrive (tape loop) carts!!

Can you do a video about setting up a small lab such as yours. Equipment that you have, most useful tools, chemicals, brands, etc. There's like a million variations of DeoxIt & solder braid, which do you use? Perhaps more info on solder station wattage, solder diameter & type. Parts suppliers and what items do you use on a daily basis...

I know you said that no alignment is necessary. But this is a pet peeve of mine. The head alignment for these types if drives is supposed to be done by loosening the three allen bolts on the head mechanism, two on the bottom near the spindle (paint-locked) and the third on the top extreme rear, on the "hinge" plate. Then, and only after loosening the those bolts, can the eccentric head screw (also on the hinge plate beside that the third locking bolt) be used to perform an alignment.

My first disk drive that I used with my 400 was an 810 with the latching door on it. It eventually broke and would not position the head. I was able to determine that the head would still read by manually moving the head. However, I never tried to repair the drive because I already had 2 1050 drives by that time with US Doubler kits that made them true double density and high speed I/O. BTW, if you hold down the Option key when powering on the computer it will bypass BASIC and boot directly into DOS.

Adrian I've been watching your videos for the past couple months, thank you very much for the hours of entertainment you have provided me.

C010745-03 is the 6507

I still use floppy discs regularly, and have learned a few things about how to keep them working. Most importantly, old or unknown discs frequently shed dirt, mould or bits of oxide even after they've been cleaned. This gets straight on to the heads and not only clogs them up but then damages (by scratching) the surface of other discs put in the same drive. A cleaning disc with IPA won't remove all this dirt from the heads. The only way to get it off is to manually clean the heads with a swab and cotton bud with IPA or even a stronger solvent (I use brake cleaner to deal with the really difficult stuff). It's important to do this straight after using any disc which looks dirty or spotty or makes unusual scraping noises. The clogging of the heads can explain all sorts of strange flaky behaviour, drives which were working will stop working or only work intermittently. A really good manual head clean sorts out the problems and prevents damage to other discs.

Last night I dreamed that I found the Commodore 64 mum and dad bought for us back in the 1980s. I was so chuffed, and was thinking that now all I had to do, was find the old floppy disk drive, too. Then I woke up. Disappointed!!! This'll do as a substitute.

The top tow drives at the end have their tops and bottoms switched between the drives. The front of the case is oxidized differently and you can see the difference in the color.

Atari, about time. Thanks for changing it up. Love your videos.

This video was super fun! Listening and watching Adrian working through the diagnostic process is not only fun, but it helps me develop those mental processes and tools I use when working on my own old computers.

Awesome, thanks for the Atari content! I enjoyed it very much!

Super exciting video that showcases what I like so much about this (and the second) channel: Your excellent commentary (thinking out loud) and your use of split screen and sometimes the audio to bring us along. BR, Per

We had a whole lab full of atari computers in middle school. Of course in typing class everyone turned the volume up all the way while loading the word processor off of disk all at the same time.

I painted a stripe on the side of the spindle with the sticker and used a digital tach to read and adjust the rpm. kind of a hack but it worked.

I'm sure people will agree with me, the videos that you think aren't worthy of uploading or didn't succeed with your goal etc are really something that I would like to watch and follow along with, so I might learn from going down the wrong path or misunderstanding a system or doing something that causes other damage etc, it's not a failure if you and others can learn from it, and we can all talk about what we think went wrong or methods that might be better or easier, and much more, we might all learn more from a video that you think was unsuccessful, a failure, boring, or even embarrassed about, you could absolutely release it between scheduled videos and put them into a playlist for us turbo nerds, inexperienced, new techs old techs masters of diagnostic magic or the guys that just got their first used digital multimeter or oscilloscope, upvote this comment so he knows how many people are interested and supportive of the failures just as much as the successful ventures in repairs! I hope everyone is having a great day or night! I appreciate your time and effort! And as always much love and prosperity to all of my brothers and sisters!

Interesting and entertaining video. I always make the time to enjoy your i hour videos, that cover a topic from beginning to end. I was never an Atari guy, but found the discussion and repair of the drives was very worth while. Back in 1978, I bought a Vic 20, and as soon as they became available, I graduated to the C-64. I used the Commodore cassettes, until I bought an MSD dual drive (cost me over $800,00 Cdn back then), and an IEEE488 interface for the drive. The MSD dual drive, was not always able to work with the copy protection, but it loaded all the games I was interested in playing. (I wasn't much of a gamer). I keep wanting to forget the 8 bit computers, but you keep reviving my interest. (I still have my C-64 and the drive)

Techmoan boils misshaped belts in water for a few minutes so they restore their original shape.

Without further ado, an upvote!

Some great disk-overies!

About time the Atari are now showed in here.. Those are the best 8-bit computer ever made imo.

Great job you did Adrian. Nice content. Greetings from Steven from the Netherlands

The 800XL is not compatible with Gorf. There is a translator disk that loads the old 800 ROM image which might help. Same deal with the second title. You just had bad luck picking two (rare) XL incompatible games.

1:01 oh my heart, ranasystems

I'm surprised no one is making new SIO cables. Given cottage vendors are atound for just about everything now, I figured there'd be enough interest for it. I'd buy several!

I really enjoyed this one, not sure why particularly, but thumbs up!

Another great repair saga!

If you like FujiNet for the Atari 8-bit you also might like the PlusCart for the Atari 2600.

I would really like to learn more about the FujiNet. Sounds like a great project. I have had plenty of experience with floppy disk drives over the years and I do not have a great affinity for them even all these years later. Of all the files I have ever lost 100% were on floppy disks.

Some Tandon drives do have a metal pin in place of the plastic pins on the loading lever. The one in my 5150 has one. Rana made a double sided drive for the Apple II called the Elite which could read MS-DOS disks.

27:57 Yes, indeed they are very good quality. Nippon Chemicon are the best.

This was a great video. Please more Atari 8-Bit content! 🙂

Atari machines were amazing, I miss them....

Lost tons of Amiga floppy games, sadly. The issue is I had nowhere else to put them, so they just ended up under the stairs for 20 years until I decided to see if it still worked. Computer is fine, even the hard drive is still kicking, but a lot of the disks no longer work. Thanks to the internet, I haven't really lost anything, I can pull down images and write them to a new disk. I do still have all the original disks, though.

I remember back in middle school wanting he Atari, because apple was too expensive and the Vic hadn’t come out yet… just WAAAAY too pricy for us at the time… I hated the 400 keyboard, and the 800 was like 1200$ they wanted 1000$ for the 810 drive, and I wasn’t going to use a tape after learning on the apple II then commodore released the budget friendly 64, and I was hooked.

That was a good video Ive never had any experiance with atari drives I was surprised that those units had so much logic onboard that was interesting. Once again thanks for the great content. ive learned a ton from your videos If I find anything rare I will email you Now if Mr Usagi could post a video on the Bendex my rare computer wishes would all be granted

I had purchased an 800XL computer a few years back that came with a 1050 disk drive. Sadly the drive didn't read the disks but I found a refurbished one on eBay that came with a custom switch to tell the drive if I wanna copy, write or erase. I still have the non-functioning one, too. Boxes and everything!

I had one of those - switched fromAtari dos to Sparta dos. Atari dos would only r/w to one side Sparta would r/w both sides so you got twice the capacity.

Those Atari 810 drives always had a Star Wars motif to their case design. Tie-fighter shape with an X-fighter inspired logo? Although the logo more closely resembles the Batllestar Galactica Viper. Dunno. May the 4th was weighing on my mind. 🙂

I haven't seen any videos about the Atari Happy Chip for Atari Disk Drives. It gave the 1050 double density instead of 1.5 and allowed you to copy pretty much any disk including the copy protection. I had one for the 810 and the only title I had an issue with was Alternate Reality.

This is so-called recertified drive, from one of the "Authorized Service Centre", who performed "logged checking", sending a copy after to whoever.

FWIW the RIOT chip is reasonably available, you're thinking of the 6530 which was the mask-ROM based predecessor to the 6532 which was used on the KIM and such (and is now very rare due to failures, and you need the RIGHT one for your application because it's mask-ROM)

RE: Apple Disk ][, I believe the disk controller was an add-on. The reason being that you could buy a second Disk ][ to operate off one controller. In the //e days, the Duodisk included the floppy controller, that used the DB-19 connector (same pinout as the later Unidisk 525 and the //c external drive). The Duodisk was slightly less expensive than two Disk ]['s and the controller card. I helped my parents price out a //e right around the time that the Enhanced //e came out 😊

I have an ALPS mechanism CBM 1541 which measured fine regarding its heads, but wouldn't want to read or write. I let it sit for half a year and wanted to take it apart for parts, checking it one more time: and yeah, it started working! I think you have to threaten the drives to make them work again...

40:00 When doing where you're using software to control hardware, it may be helpful to swap the overhead camera and screen capture to where we can see the hardware itself (the floppy drive in this case, though this happens regularly in other videos for other things as well) better. Even when small, we should still be able to read the screen well enough to tell what is going on with it in the bottom corner.

If u hold option down when you turn the xl on you bypass the built in basic and boot from the disk

As an Atari 8 bit fan, I had to give up on my disk drive (800xl version) as it was too unreliable. Fujinet wasn't a thing back then so I have an SIO2SD, another great piece of kit

The MC6810 indeed is a very small RAM chip - 128 bytes, in fact. I find it absolutely comical that for as small as it is, it has no less than SIX chip select lines!

I think “The Badge Man” is the go to for retro computer badges and stickers. Perifractic mentioned him in his Saturday video today oddly enough!

I remember have one of those notch punches when I had a Commodore 64.

DOH! You have the top drive's cover on the middle drive and vice versa the middle drives top on the top drive! My OCD is screaming!

Just a heads-up for future reference, the Atari XF551 360K DSDD drive for the A8 computers was 300 RPM. So if you end up with one of those at some point, be aware of that. I'm not sure if any of the third party drives ran at 300 RPM.

On that wonky heads connector, re-solder the header on the board. If that doesn't fix it, check the signal levels and waveforms at the analog board's output connector and compare those with one of the working drives, then work backwards through the signal chain if theirs a problem. OR start the same comparisons after some of the first and subsequent active components on the analog board from the heads connector end. Even just some comparative idle voltage checks on transistor, diode, and ICs might identify a marginal component even without signal comparisons. These checks are to make sure your problem isn't due to low head signal amplification which thereby makes that connector so sensitive to perfect contact. If the analog board circuitry isn't the problem and there is no way to remove the female pins in the heads connector to make sure they aren't spread or that their possibly just crimped wire connections aren't defective, cut the connector off and replace it with the one from the parts Tandon drive.

Way too long? 1h 18m was perfect - not rushed nor drawn out. I really did enjoy every minute of it. Perhaps an abridged version could be made and posted on ADB2 for those that want shorter?

Talking about WD FDC 17XX family, an error persistst into silycone, as it seems from 1771 up to 1793 at least, some (M)FM patterns are able to trigger MCU to repositing (not justMOVE) the HEADS

Back in the day I used to leave the screws out of the case of my old 810. Why? No data separator and flaky speed control. So run speed testing software, pop the cover, and adjust then use drive. Another day another readjust. Later I got a 1050 that had no such problems. 🙃

I miss my old 800 xl set up from the 80's. I had till mod 90's

Marking is important, as i rember one version of 1541 had one connector reversed (i think heads) and puzzled my friend serviceman, at first he refused to believe my visual memory but after failed attempt he caved 😉

I still have my modified Atari 810 "Happy Drive" although it hasn't been powered on in over a decade.

oh man I have 3 of these that need repair, this is perfect for me! thanks🙂

Yeah ! Why Ioved ZX ? Because of 640kb BETA Disks...... But it used different WD IC, more advanced FDC1793 :)

The 6507 and RIOT are both readily available due to the huge number used in 2600s, so that wouldn't be a problem.

I remember GORF not being compatible with the XL/XE, at least the cartridge version. I installed an Ultimate1MB into my 130XE and it allows me to switch the boot ROM images in the menu 😎

at 14:45 I actually also only had 3 screws in mine but was new in box. Figured I'd pull it out to inspect it as well while watching the video as you went through them and sure enough, only 3 screws!? This was a NOS drive with tape still on the box. Quite curious.

I have an 800XL and an XEGS, as well as the newer half-height drive, and even the cable to connect them. And I have never tried it out, as I have no Atari floppies.

Try using the "Translator" disk which patches the XL/XE OS and allows most incompatible games for the 400/800 to work. This will likely fix the game issue.

Before checking if a head has a different alignment, you should definately bulk-erase the disk you use because you never know _how_ blank a "blank" disk really is and any magnetization left from previous tracks would interfere with the test.

I had an idea of how you could test for a head/alignment issue. Couldn't you connect the head to a scope so you could visually see what is being read off the disk. You should be able to save a known good waveform for each format, and compare a known good to the problem drive.

One of the problems I ran in to was having a disk in the drive and turning it on erased part of the disk the heads moved. I am using 1050 drives.

That the color of my old 1980 electrolux vacum ! Lol

When this drive hits 288 RPM you're gonna see some serious data! 😛 Floppies? Where we're going we don't need floppies! (Doc Brown plugs in Fujinet) 🤠

Single side but can be made to do double density.

Probably need the "Translator" disk for that game to work right. This is a disk that bank-switches out the real ROM and loads an older ROM revision into the underlying RAM instead. Lots of software back then relied on unofficial uses of ROM code that broke when Atari updated it. Do note that the Translator disk was a "flippy", with two slightly different versions, one per side. So you might need to try each one (not too likely, but hey).

Head problem?! I've never had any complaints!

What oil do you use to lubricate the rails?

I like that tower of C64 carts you have behind you at the end. What is that holder? Is it something made for that purpose?