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dukes909

810 Drive Woes

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So i am trying to archive my disks as described and helped by folks here in a previous post (big thank you) to .atr files.  However I only got about 1/4 of the way through my old disks when the 810 drive has stopped reading disks.  It powers up and the head moves etc. but it will not boot a disk at all.  I read another post on here that described my problem to a "T" including the single beep that occurs I guess when the head rezeroes.  I have cleaned the head with alcohol and dusted out the inside, and disconnected all the pin connectors inside to no avail (I tried several disks).  In the other post the person says that by applying pressure with his finger to the head he was able to get the drive to read the disk.  I tried that and it doesn't work. I am not sure how that person measured the RPM's by marking the spindle and filming it and counting..I tried that too but wasn't able to see the mark on the spindle in the video...maybe I need to watch the video on something other than my phone :lol:

 

I am thinking of getting the Uno cart so I can load the 810 diagnostics cartridge as mentioned in the field service manual for this drive. Will that work?  Any other ideas or suggestions?...

 

Cheers

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810s are notorious for poor speed control. You can try just a little turn on the RPM pot and then test for read. If that does not work, turn just a little the other way. Once you read disks to some extent, you can run an RPM test and dial it in to 288 RPM.

 

The danger in this kind of procedure is that you will lose control of where the drive was when you started. Not the end of the World, but challenging for the Inexperienced.

 

Bob

 

 

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Does your 810 have a PCB on the top of the drive mechanism with a ribbon cable to the PCB at the rear of the case?

If it does you have the new version of the power board, and the board on the mechanism is the analog board.

If it doesn't you would have the original power board that is prone to failure, which could be the issue with your 810.

 

The image below is of the newer power board/analog board combination, the power board is on the left and the analog board on the right installs on top of the drive mechanism with a ribbon cable between. The image is from an eBay auction, the seller is myatari.

 

810 power and analog boards.png

Edited by BillC
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12 hours ago, bob1200xl said:

810s are notorious for poor speed control. You can try just a little turn on the RPM pot and then test for read. If that does not work, turn just a little the other way. Once you read disks to some extent, you can run an RPM test and dial it in to 288 RPM.

 

The danger in this kind of procedure is that you will lose control of where the drive was when you started. Not the end of the World, but challenging for the Inexperienced.

 

Bob

 

 

I think I can be careful and keep track of how many 1/4 turns or whatever.  Do they drives typically slow down or speed up as they get older or either way?

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9 hours ago, BillC said:

Does your 810 have a PCB on the top of the drive mechanism with a ribbon cable to the PCB at the rear of the case?

I think that is the one I have:

C786-E095-BB54-46-F0-8-B73-4-C661881-FDC

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5 hours ago, dukes909 said:

I think I can be careful and keep track of how many 1/4 turns or whatever.  Do they drives typically slow down or speed up as they get older or either way?

I think the drive slows down over time. Perhaps the bearing load increases as the drive gets older.

 

I would turn 1/8 of a turn. Listen to the drive run faster or slower.

 

Bob

 

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I would also check the head alignment.     The quick daig method would be, With the cover off, when it zeros and you get the one beep, put some light pressure forward on the head to see if it can pick up the track.   Adjusting is a bigger trick.  Out of the 4 (5?) 810's I have, I've never had to touch the spindle RPM, but have had to adjust the head on the Tandon drive a couple times. 

 

But yeah, if you can get that 810 diag cart, that's the real key, otherwise you're just stabbing in the dark.

 

 

 

 

Edited by Mechanicjay
more info
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Before I adjusted the drive speed blindly (by ear), I'd search for a copy of one of the later DOS 2.5 hacks out there (DOS 2.6, 2.8, "yellow DOS", "black DOS", etc). These typically include drive speed measurements in RPM as part of their additional functions.

 

image.thumb.png.f840b7ba3944918f822913400ed99356.png

 

 

DOS v2.6f (1983)(Atari)[m].atr

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4 minutes ago, DrVenkman said:

Before I adjusted the drive speed blindly (by ear), I'd search for a copy of one of the later DOS 2.5 hacks out there (DOS 2.6, 2.8, "yellow DOS", "black DOS", etc). These typically include drive speed measurements in RPM as part of their additional functions.

 

image.thumb.png.f840b7ba3944918f822913400ed99356.png

 

 

DOS v2.6f (1983)(Atari)[m].atr 90.02 kB · 1 download

Would I boot this using RespeQt and then use it to access the bad drive? It won’t boot anything on it’s own right now. 😥

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Just now, dukes909 said:

Would I boot this using RespeQt and then use it to access the bad drive? It won’t boot anything on it’s own right now. 😥

Yes, basically. Or via SDrive, SDrive-MAX, FujiNet, SIDE2, SIDE3, etc ... Set your troublesome drive as D2: and boot from the other device.

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7 minutes ago, DrVenkman said:

Yes, basically. Or via SDrive, SDrive-MAX, FujiNet, SIDE2, SIDE3, etc ... Set your troublesome drive as D2: and boot from the other device.

Excellent, thanks!

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22 hours ago, DrVenkman said:

Before I adjusted the drive speed blindly (by ear), I'd search for a copy of one of the later DOS 2.5 hacks out there (DOS 2.6, 2.8, "yellow DOS", "black DOS", etc). These typically include drive speed measurements in RPM as part of their additional functions.

 

 

DOS 2.6 that you attached wouldn't boot on my 800. Should it?  I can boot 2.0 normally through RespeQt..however it will not talk to my 810 drive set as drive 2....agggghghh

IMG-3021.jpg

IMG-3022.jpg

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Can you just turn off the 810 (set the address as D1:), boot that DOS and then turn on the 810 and turn off whatever you booted from? That should allow you to access the 810 as D1:.

 

Some DOS variants will not recognize drives up the chain if they don't respond to the polling at power on. You did say that the drive tries to read - it has to have some functionality for that to happen. It should respond as D1:.

 

Bob

 

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15 hours ago, dukes909 said:

IMG-3022.jpg

What are those heart characters at the bottom of your screen? If those "randomly appeared" it might be indicative of other issues with your 800 like bad RAM or bad contacts on IC(s)...

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3 minutes ago, Nezgar said:

What are those heart characters at the bottom of your screen? If those "randomly appeared" it might be indicative of other issues with your 800 like bad RAM or bad contacts on IC(s)...

Yes they just started and I was going to ask about them in a separate post.  Dang, more problems!  I guess I can pull each RAM card out to see if they go away?  

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16 minutes ago, dukes909 said:

Yes they just started and I was going to ask about them in a separate post.  Dang, more problems!  I guess I can pull each RAM card out to see if they go away?  

Pull the carts, clean the edge connectors and slot connectors with isopropyl or electronics cleaner (Deoxit is a miracle) and see if the problems go away. If not, pull the cards again. Remove, clean and re-seat the DRAM chips and support logic and try again. 

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23 hours ago, bob1200xl said:

Can you just turn off the 810 (set the address as D1:), boot that DOS and then turn on the 810 and turn off whatever you booted from? That should allow you to access the 810 as D1:.

 

Some DOS variants will not recognize drives up the chain if they don't respond to the polling at power on. You did say that the drive tries to read - it has to have some functionality for that to happen. It should respond as D1:.

 

Bob

 

I tried this and it worked (letting me access the drive from DOS), and the drive responds to commands but  the drive still won't read anything off the disks. BOOOO.  DANG

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8 hours ago, DrVenkman said:

Pull the carts, clean the edge connectors and slot connectors with isopropyl or electronics cleaner (Deoxit is a miracle) and see if the problems go away. If not, pull the cards again. Remove, clean and re-seat the DRAM chips and support logic and try again. 

Ok I have 48k in my 800. I narrowed it down to one of the 3 16k modules by swapping them around.  Without it in there I get no weird characters.  With it in there and a BASIC cartridge, BASIC will start but instead of a nice blue background, it is a weird teal color!  Without that cartridge and a BASIC cartridge inserted I get the normal blue background.  Now should I reseat each chip on that cartridge?  I feel like I will bend one of the pins pulling them out knowing my klutsy self...

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Try formatting a blank disk. If the drive is out of alignment, it may work with its 'own' disks. Otherwise, it's time to tweak the RPM.

 

Bob

 

Just leave out the bad RAM board and run with 32K.

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21 minutes ago, bob1200xl said:

Try formatting a blank disk. If the drive is out of alignment, it may work with its 'own' disks. Otherwise, it's time to tweak the RPM.

 

Bob

 

Just leave out the bad RAM board and run with 32K.

Tried this and the drive responds  but I get error 139.

 

I also tried booting the DOS 2.6 or 2.8 that have the speed utility in it and it won’t boot.  I did get DiskWizardII to load and I ran the speed utility on there, and it spun the drive and spun the drive and spun the drive... but it never reported a speed.  So, is there a logic chip in there that is not passing the correct speed info?

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50 minutes ago, dukes909 said:

So, is there a logic chip in there that is not passing the correct speed info?

The 810 firmware exposes very little to software control, mostly just simple read/write/format commands. So - because of this all an RPM check program does is a continuous read of the same sector, and time the delay. Since the drive can only buffer one sector at a time, a request of the same sector will have to wait for the disk to complete a full revolution to read it again.

 

If the drive cannot read the sector at all, thats why the RPM check would fail as well.

 

At the point the RPM check is "trying" to read a sector, this is the time to try adjusting the RPM up or down to see if it helps get any successful reads. Or applying a little pressure forwards or backwards to get a sense if alignment may be an issue.

 

But trying to format a disk is also a good test as previously mentioned - passing this would point to an alignment issue. Observe the format behavior. Normal 810 format behaviour is format tracks 0 through 39, then verify from 39 to 0. Even if the disk is 100% bad, it should step through 0-39, then error out on track 39. If you observe it step backwards a few tracks before failing, that means it actually successfully verified a few tracks - which is a start!

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make sure all the connectors are on the right place, facing the correct direction and no pins are missed/ skipped or otherwise. carefully inspect that no wire is torn or broken/not firmly seated.

 

Clean the drive head...

 

then try with a known good disk to read the RPM, if no reading takes place... slight pressure on the base (large bottom part) of the head carriage in towards the spindle or pulled back towards the power board my emit some beeps... if that's the case you will need to align the drive.

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It seems does not work on Altirra emulator. It just destroyed disk image of that 2.6 F. Nothing show a true speed , just appear as "XXX" on emulator. So I have to test on the real hardware Atari 800 with 810 disk drive.

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13 hours ago, Caterpiggle said:

It seems does not work on Altirra emulator. It just destroyed disk image of that 2.6 F. Nothing show a true speed , just appear as "XXX" on emulator. So I have to test on the real hardware Atari 800 with 810 disk drive.

An drive under emulation by default returns any requested sector almost immediately to the software. The software would be confused by the "fast" speed, and probably explains the XXX result. You would have to enable optional modes such as "accurate sector timing" (under disk drive options) or full drive emulation.

 

Edit: I just tested the DOS 2.6f RPM function myself under Altirra... doesn't work with only accurate sector timing... It does however work with full drive emulation (of an 810 or 1050 for instance) AND accurate sector timing enabled... it performs 19 reads of sector 1 then stops displaying the result.

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