jaek_3 Posted June 16, 2018 Share Posted June 16, 2018 (edited) My 810 is having some problems... surprise, huh? Well, it's able to READ disks thoroughly since it boots into DOS 2.5 no problem. The trouble comes when I try formatting disks. The drive head goes all the way to track 1 as you would normally expect and works its way to the edge of the disk closest to the spindle hole, but after that it very slowly starts to work its way back, maybe taking one step every 15 seconds. Eventually it'll stop and go all the way back to track 1 and repeat the process endlessly, eventually spitting out error - 173. I've tried lightly cleaning the drive head with alcohol and a Q-tip to no avail. Edited June 17, 2018 by jaek_3 Quote Link to comment Share on other sites More sharing options...
+kheller2 Posted June 17, 2018 Share Posted June 17, 2018 Silly question: you are using SD or DD disks right? Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Silly question: you are using SD or DD disks right? I think so? I have a lot of floppy disks, let me specifically try an SD disk and then a DD disk. At any rate, I don't think it'd be able to read at all if it wasn't the right disk type, right? Quote Link to comment Share on other sites More sharing options...
Rybags Posted June 17, 2018 Share Posted June 17, 2018 I'm fairly sure the 810 actually formats backwards, starting track 40 thru 1 (might vary according to firmware revision). Then there's the readback/verify process where it's supposed to build a list of bad sectors then send it to the computer. Both phases involve no comms with the host so the R/W operations are high speed compared to normal. According to a 1050 reverse-engineered firmware listing I have the readback process does it a sector at a time and will retry bad sectors which could explain the slowness. Quote Link to comment Share on other sites More sharing options...
_The Doctor__ Posted June 17, 2018 Share Posted June 17, 2018 Yep, and it wouldn't hurt to re seat or wiggle boards and chips, and check the rpm's. Always seems to do the trick. Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted June 17, 2018 Share Posted June 17, 2018 (edited) RPM is good to check. Also, try different disks. I find my 810 is much more sensitive to marginal disks compared to the 1050. 810 Rev B and C format this way: - Sitting idle at track 39 (starting from 0) - When format command issued, seek to and format track 0, then incrementally to 39 - Verify track 39, then step each track backwards to 0. - Format success is returned to DOS, and DOS usually writes boot sectors, directory, VTOC. DOS 2.x variants this is track 0 and 20, In the case of this video SpartaDOS was used, so this is all written on track 0 only. - About 5-6 seconds after last I/O activity head seeks back to track 39 and stops motor Quick video of my drive with Rev C as it formats for reference: Sorry it's a bit blurry, (fixed focus flip) but you can see and hear what's important! Edited June 17, 2018 by Nezgar 1 Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Yeah, that's what mine does, but apparantly it starts to mess up in the verify stage. How exactly do I check or adjust the RPM? I think old floppy drives used to have a little sticker for calibration purposes on the motor right? Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted June 17, 2018 Share Posted June 17, 2018 Various 3rd party dos's often had an RPM tool - ie sparta 3.2, I think 3.2f had it - 'RPM.COM' Quote Link to comment Share on other sites More sharing options...
Fox-1 / mnx Posted June 17, 2018 Share Posted June 17, 2018 BASIC RPM tool: http://atari.fox-1.nl/atari-400-800-xl-xe/400-800-xl-xe-tools/dskrpm/ DOS 2.8F with RPM feature: http://atari.fox-1.nl/atari-400-800-xl-xe/400-800-xl-xe-tools/dos-2-8f/ DOS 2.5F (about the same as above): http://atari.fox-1.nl/atari-400-800-xl-xe/400-800-xl-xe-tools/dos-2-5f/ SmartDOS 8.2D with SpeedCheck: http://atari.fox-1.nl/atari-400-800-xl-xe/400-800-xl-xe-tools/smartdos-8-2d/ SmartDOS 1.5R Beta with Speedcheck: http://atari.fox-1.nl/atari-400-800-xl-xe/400-800-xl-xe-tools/smartdos-1-5r-beta-test-version/ 1 Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Alright, DOS 2.8f gives me a reading of 267 RPM, as does the BASIC tool. I've read the ideal speed is somewhere between 288 and 292, how do I go about adjusting the motor speed? There's a big potentiometer on the board, is that it? I've attached a pic of it Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Alright, I adjusted it to 292, but now the verification process goes even slower than it did before Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted June 17, 2018 Share Posted June 17, 2018 Ok good good! 288 is your target RPM. there's a little pot adjustment pot with a small screw like knob you can adjust with a small flat head screwdriver on the bottom power board while the RPM test is running. (Just be very careful not to touch/short anything with the tip while doing it!) Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted June 17, 2018 Share Posted June 17, 2018 Hmmmmmm your power board picture looks different than mine - maybe yours has the original problematic board - pretty much known guaraneed to fail or cause unstable operation. Does your drive mech have the additional board over top? And the data seperator board on top of the side board? (Inside that metal shield). Those were the other components upgraded/replaced in later / serviced drives. Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Ok good good! 288 is your target RPM. there's a little pot adjustment pot with a small screw like knob you can adjust with a small flat head screwdriver on the bottom power board while the RPM test is running. (Just be very careful not to touch/short anything with the tip while doing it!) Bummer! I got it to 288 but the formatting process still doesn't complete! Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Alright well this is weird, now the RPM tool is fluctuating pretty wildly between 240-270. Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted June 17, 2018 Share Posted June 17, 2018 (edited) Yep, that sounds like the failure mode of the older type of power board. Get a new one from Best Electronics - along with the data seperator for the side board, and the top analog board if you don't already have those too: http://www.best-electronics-ca.com/8-bit_.htm He has a good writeup of the problems there too. Edited June 17, 2018 by Nezgar Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted June 17, 2018 Share Posted June 17, 2018 Quoting from the page: The Atari 810 disk drives without the Data separator board had all kinds of Read and Write 810 Head problems. The single 810 rear power boards had all kinds of speed problems that seem to change all of the time without making any kind of speed adjustments on the single rear 810 power board. Both known 810 problems we latter fixed in the Atari 810 production run with a new plug in 810 Data Separator board (which cured most of the 810 Read and Write electronic data problems). The second Atari 810 Major problem was cured with what is known within Atari Engineering as the Atari 810 Grass Valley board set (where in California it was designed). This Atari Engineering Grass Valley 810 new board set cured all of the Atari 810 speed problems. It consisted of a new redesigned / improved replacement 810 rear power board and a second daughter board (sat over the 810 Disk Drive mech. and was connected to the rear 810 board with a 10 pin wire harness and to the 810 Head wire harness). The second Grass Valley 810 daughter board helped to separate and boost the Atari 810 disk drive Head signals. Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Yeah, that description exactly matches my unit. Sad. I noticed some of the capacitors on the board seems to have been replaced at one point or another so I'll try replacing them to see if there's any improvement. Quote Link to comment Share on other sites More sharing options...
Fox-1 / mnx Posted June 17, 2018 Share Posted June 17, 2018 Never had a (working) 810 but I'm curious about the "bad boards" issue. Sure, replacement boards are easy to get by (yet) but what does it take to repair a "bad board" in such way that it won't go bad again? Or not that quick at least. They worked at one point so it must be something that can be solved. Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Never had a (working) 810 but I'm curious about the "bad boards" issue. Sure, replacement boards are easy to get by (yet) but what does it take to repair a "bad board" in such way that it won't go bad again? Or not that quick at least. They worked at one point so it must be something that can be solved. Well I figure if the issue is with a motor that isn't spinning at a stable speed then it's probably a cap issue seeing as how capacitors are used to stabilize and smooth out incoming current Quote Link to comment Share on other sites More sharing options...
Fox-1 / mnx Posted June 17, 2018 Share Posted June 17, 2018 Issues like this often point to caps because of their nature of how they work and wear out, but if the problem is common, why is it there's no readily available solution? (or maybe there is one I just don't know about) If it really turns out to be caps, modern ones should make the problem go away for a long time. No need to order expensive boards (when overseas) then. Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 17, 2018 Author Share Posted June 17, 2018 Issues like this often point to caps because of their nature of how they work and wear out, but if the problem is common, why is it there's no readily available solution? (or maybe there is one I just don't know about) If it really turns out to be caps, modern ones should make the problem go away for a long time. No need to order expensive boards (when overseas) then. Well I ordered some replacements, I'll keep you posted! Also from what I understand my particular 810 unit isn't particularly common anyway Quote Link to comment Share on other sites More sharing options...
+Nezgar Posted June 17, 2018 Share Posted June 17, 2018 (edited) Yeah, looks like yours is a very early production model 810. Never seen one myself, but I'm impressed it was still working at all from what I've read about them. Curious to hear if you are able to stabilize it with component replacements, but sorry that's beyond my ability to help currently. Looks like no top board in yours, so I'm guessing your side board is highly likely to have no data seperator board, and the older Rev B ROM. I did a good search to find that older ROM as it hadn't been dumped until recently. Part # on the chip is CO11299B, which formats disks with a 30% slower 13:1 sector interleave: http://atariage.com/forums/topic/279363-the-atari-810-revision-b-rom-has-finally-been-found-dumped/?hl=%2B810+%2Brevision&do=findComment&comment=4041579 Edited June 17, 2018 by Nezgar Quote Link to comment Share on other sites More sharing options...
jaek_3 Posted June 18, 2018 Author Share Posted June 18, 2018 (edited) Turns out the three big 4700uf 25v capacitors are... three lead caps? Can't say I've ever seen those before, although there are two identical caps on the main Atari 800 power board. Edited June 18, 2018 by jaek_3 Quote Link to comment Share on other sites More sharing options...
Fox-1 / mnx Posted June 18, 2018 Share Posted June 18, 2018 Three lead caps may be used with symetric power supplies. They can be replaced with two separate caps if physically possible. Quote Link to comment Share on other sites More sharing options...
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