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ΛΛdZ
Registered: Jul 2005
Posts: 153 |
Drive alignment
I have some problematic 1541's which I have tested on speed and alignment, with various old tools. Drive-speed was easy to fix but alignment is a bitch to control and adjust! I'm new in the area of fixing drives, so I need some experienced advise on tools to use and info on the techniques :)
Request: Tools (which you use with success) and info/text on how to fix the alignment!
Thanks! |
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chatGPZ
Registered: Dec 2001
Posts: 11386 |
you cant really align a drive properly without an analogue alignment disk, which is unfortunatly almost impossible to get (and impossible to duplicate by standard methods, they must be written with special machines).
there is supposed to be a way to do it with a known "good" disk (original, eg the test/demo disk), but i dont know the details... i only know how the proper way works =P
that said, forget ANY method that doesnt involve a reference disk and measuring with an oscilloscope. you'll only make it worse. |
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ready.
Registered: Feb 2003
Posts: 441 |
I recently bought from Amazon the book: Commodore 1541 Troubleshooting and Repair Guide, Google for it and get it, there are still available copies for a cheap prize. There are various method for drive alignment, but as Groepaz said the best method is to use an oscilloscope. |
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Conrad
Registered: Nov 2006
Posts: 849 |
There's also this:
http://codebase64.org/lib/exe/fetch.php?id=books%3Astart&cache=..
... read up on chapter 3 in the .pdf... hope this helps a bit. |
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ready.
Registered: Feb 2003
Posts: 441 |
yes same book.
It is interesting to notice that on page 172 there is a warning against permanent damage to the drive 1541 which can be done via software:
Never write to memory locations at or above $8000. A bus conflict may occur, causing permantent damage to UB3,UB4 or UC4.
I didn't know that.
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Devia
Registered: Oct 2004
Posts: 401 |
Check my post here: http://noname.c64.org/csdb/forums/?roomid=7&topicid=39351#40037
As you can gather from that post, I'm not quite in agreement with Groepaz in regards to using a scope.. It really is a matter of preference and/or skill. With a bit of excersice and understanding of the drive mech, adjusting a mech to match the alignment of another mech close enough for error free operation is not that difficult. The important thing to keep in mind here though, is "DON'T TOUCH THE ALIGNMENT IF IT AIN'T BROKEN!" - then you'll just risk ending up with a set of drives in alignment with eachother, but not the rest of the world ;-)
If you use so called "original" disks as reference disks, be sure to test with several before setteling on _your_ reference, since many "original" disks are actually not all that well written.
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Mace
Registered: May 2002
Posts: 1799 |
Come to X-2008 and I'll bring my set of alignment disks :)
Nope, sorry, not for sale. |
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Graham
Account closed
Registered: Dec 2002
Posts: 990 |
I once tried to align a mech and after hours i gave up. Occassionally I was able to load a dir, but I never came close to a good alignment. |
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Mace
Registered: May 2002
Posts: 1799 |
It's a painstaking job and it requires patience and a steady hand.
I managed to fix a drive without prior experience, so it CAN be done. |
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maestro
Registered: Mar 2004
Posts: 727 |
well if there not for sale mace how about some images of them so we can put them onto disk ourselves :) |
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chatGPZ
Registered: Dec 2001
Posts: 11386 |
read again what i wrote before :) alignment disks contain an _analogue_ signal. you cant make images from them or even copy them with normal drives. |
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enthusi
Registered: May 2004
Posts: 677 |
I saw throw away all diskdrives and move on! use tapes |
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Mace
Registered: May 2002
Posts: 1799 |
Oh, I must add that from all drives that I handled, only 1 had aligment problems.
The rest had broken VIA chips, dirty heads, sticky bearings, slippery mechanics or broken PSUs...
So go figure :) |
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Graham
Account closed
Registered: Dec 2002
Posts: 990 |
@Mace: You were just lucky :)
Also, without proper measurement devices you have no idea about the quality of your alignment. "Reads data" only says that you are near the track. |
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Devia
Registered: Oct 2004
Posts: 401 |
By reading properly from all "full" tracks and making sure you cannot read from any "half" tracks between all the "full" tracks, you are pretty damn close to a "good" alignment imho.
It all depends on the disk you are testing with, how it was written and what state the disk was in before it was written of course.
But hovering over a track and continously reading it, you can carefully knock the stepping motor back and forth over that track until you get a feeling for where the center is.. just be careful not to "jump tracks" ;-)
In fact, by only loosening the screws very little, just enough for the motor to move it self, you could write a program which did the alignment automatically by bumping the head which ever way needed... well.. in theory at least ;-)
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hollowman
Registered: Dec 2001
Posts: 474 |
Quote: well if there not for sale mace how about some images of them so we can put them onto disk ourselves :)
Free Spirit Softwares Drive Alignment Disk is for sale here
http://stores.ebay.com/The-Commodore-Store , and I actually managed to get a drive working with it |
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Mace
Registered: May 2002
Posts: 1799 |
Hollowman, same one I got. |
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The Shadow
Registered: Oct 2007
Posts: 304 |
I just did my first alignments on two new 1541 II drives, using the free spirit disk and an instruction manual currently printed by Micro Designs. |
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d0c
Registered: Apr 2006
Posts: 186 |
Quote: I just did my first alignments on two new 1541 II drives, using the free spirit disk and an instruction manual currently printed by Micro Designs.
and now both drives are dead? |
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ready.
Registered: Feb 2003
Posts: 441 |
there's also another place where to buy the free spirit alignament disks:
http://www.sharewareplus.co.uk/viewcart.asp?zoneid=&classid=
but it says "THIS IS A TEST SITE/THIS IS NOT A LIVE STORE!". What does it mean? Has anybody shopped from this site?
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chancer
Registered: Apr 2003
Posts: 347 |
I have had problems with my drives also, have you cleaned the heads also ? (dumb question.. but hey, I'm the person to ask)
It fixed one of the 2 drives I have with problems. theres that alchol that you buy from the chemists which might help..
ready , you mean ?
http://www.sharewareplus.co.uk/pp/Premium_Products/Free_Spirit_..
is it someone from the scene who runs it?
if you look also at the "contact us" bit , it's got a VERY odd address, so dunno if I'd trust using them.
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ready.
Registered: Feb 2003
Posts: 441 |
yes, it is strange. Also if you Google for www.sharewareplus.co.uk there are very few infos about it. It seems a guy ordered some disks to be shipped to Australia who paid lots of money (lemon64 link)...but the link does not seem to exist.
In case naybody has some feedback, please post it.
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Mace
Registered: May 2002
Posts: 1799 |
I bought that FreeSpirit kit through eBay.
The first disc that arrived was wrong: there seemed to have been a manufacturing error, so the floppy sleeve was cut and the magnetic disc was damaged.
I emailed the seller about it and within days I received 2 or 3 (can't remember) replacement floppies without additional charge!
Those worked perfectly.
The guy even warned me about copying the disk; that that wouldn't work & stuff :-)
/me = happy customer. |
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ready.
Registered: Feb 2003
Posts: 441 |
about the copying of an alignment disk. People says it will not work if the disk is copied, but what if I copy it with an aligned disk drive, then it should work, right?
Of course the more the disk drive used for copying is misaligned the worst the alignment of other disk drives will be. Basically it is just a matter of having a good referce disk. |
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MagerValp
Registered: Dec 2001
Posts: 1078 |
Again: alignment disks have *analog* data, not digital. You can't copy it with a 1541, as the 1541 can only write digital data.
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ready.
Registered: Feb 2003
Posts: 441 |
Hello all!
I just re-tuned my Oceanic drive (1541 clone) with the FreeSpirit alignment disk: the head stop needed some tuning.
Then I also used it to analize a built-in 1571 drive of a C128DCR. The drive could not read almost anything. But I discovered something very strange, to me at least. On half tracks (18.5, 19.5, 20.5,.....) the alignment condition was EXCELLENT. While on full tracks (18, 19, 20,....) the FreeSpirit program said it needed re-alignment.
I would expect a more average, but constant alignment condition, like POOR for all tracks. So, I don't know if my 1571 really needs re-alignment or it is something else that is wrong with it. Also the head stop was succesfully tested.
In case anybody has a good suggestion...
thanx
Ready. |
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chatGPZ
Registered: Dec 2001
Posts: 11386 |
Quote:
In case anybody has a good suggestion...
yes, unless you have a scope and a real alignment disk.... just DONT =P |
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The Shadow
Registered: Oct 2007
Posts: 304 |
Ready. you need to use a "jeweler's hand" and carefully turn the step motor until you at least get a "poor" every track and half track. Poor works greater than "needs re-alignment". If you can get at least "satisfactory", you will have no problems. "excellent" for half and full tracks is best but you do need to use a steady "jeweler's hand". |
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Devia
Registered: Oct 2004
Posts: 401 |
Quote: Hello all!
I just re-tuned my Oceanic drive (1541 clone) with the FreeSpirit alignment disk: the head stop needed some tuning.
Then I also used it to analize a built-in 1571 drive of a C128DCR. The drive could not read almost anything. But I discovered something very strange, to me at least. On half tracks (18.5, 19.5, 20.5,.....) the alignment condition was EXCELLENT. While on full tracks (18, 19, 20,....) the FreeSpirit program said it needed re-alignment.
I would expect a more average, but constant alignment condition, like POOR for all tracks. So, I don't know if my 1571 really needs re-alignment or it is something else that is wrong with it. Also the head stop was succesfully tested.
In case anybody has a good suggestion...
thanx
Ready.
Some drives are just fucked like that.
A few ideas pop into my head, though: Inspect the ribbon that pulls the head back and forth. If this ribbon has some "bumps" on it, that could result in the condition you're describing, I guess. If the rails the head slides on are "dirty", that might also produce a similar result.
Is it the same behaviour when stepping from 21 down to 18 as when stepping from 18 up to 21?
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ready.
Registered: Feb 2003
Posts: 441 |
@Devia: yes same behaviour. Strange thing is also that on other 1571 drives I get a quite unstable condition (i.e.: poor/satisfactory oscillating), but here I either get EXCELLENT or NEEDS RE-ALIGNMENT stable.
By the way, the Free Spirit sw yesterday help to detect that another 1571 had the opto switch for the head stop broken, since the head would not move during bump test. I then tested the opto with a voltmeter: output was always high regardless there was something in the opto or not. After replacement of the opto the drive worked again!!!
I'll do more testing on the 1571 of my 128DCR.... |
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null
Account closed
Registered: Jun 2006
Posts: 645 |
bit offtopic perhaps, but these guys are okay to buy from?
http://stores.ebay.com/The-Commodore-Store
I don't want to get screwed, not even for a small amount of money :/
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http://zomgwtfbbq.info |
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hollowman
Registered: Dec 2001
Posts: 474 |
knoeki, atleast they didnt rip me off. Also: http://feedback.ebay.com/ws/eBayISAPI.dll?ViewFeedback&userid=a..
Positive Feedback: 100%
Members who left a positive: 2646
Members who left a negative: 0
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ready.
Registered: Feb 2003
Posts: 441 |
Yes, the are trustworthy. I bought my alignment disk from them. But it seems that since this thread started and enthusiasm spread around this alignment disk, these guys rose the prize. It was 12.xx euros when I bought it, now it's 17.xx euros. They know how to make good deals!!
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null
Account closed
Registered: Jun 2006
Posts: 645 |
Quote: Yes, the are trustworthy. I bought my alignment disk from them. But it seems that since this thread started and enthusiasm spread around this alignment disk, these guys rose the prize. It was 12.xx euros when I bought it, now it's 17.xx euros. They know how to make good deals!!
well, it wasn't about the allignment disk per se, there's some other interesting stuff too.
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http://zomgwtfbbq.info |
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chancer
Registered: Apr 2003
Posts: 347 |
ready. it's not so bad, the euro is worth more than the £ for a start..
I wanted to buy some soft synths from europe, but due to the £ being not so great exchange rate wise I won't bother till its a bit better. |
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Mace
Registered: May 2002
Posts: 1799 |
Quote: ready. it's not so bad, the euro is worth more than the £ for a start..
I wanted to buy some soft synths from europe, but due to the £ being not so great exchange rate wise I won't bother till its a bit better.
No, the pound isn't worth less than the euro.
It's the dollar that is lower. |
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chancer
Registered: Apr 2003
Posts: 347 |
mace.. 75p / £0.75 = 1 euro...
go back a while £1.20 / £1.30 = 1 euro
the US dollar is normally half a UK £1.. always has been , or very near that mark £1 = $2 for a LONG time, for like 10+ years as far as I can remember
it's messed up now, it's to put people off buying European imports (and probably to stop the people coming in sending money home (not uk) ) , instead of spending it in the UK.
Some of the soft synths I want are dutch etc and can only be bought from the person direct / via their website. So because of the exchange rate I will put off buying them from their country.
I wonder if I can still get my dutch guilders changed from x95? hehe |
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MagerValp
Registered: Dec 2001
Posts: 1078 |
Quote:mace.. 75p / £0.75 = 1 euro...
go back a while £1.20 / £1.30 = 1 euro
Huh? The GBP is at an all-time low at 1.30 EUR:
http://finance.yahoo.com/echarts?s=GBPEUR=X#chart2:symbol=gbpeu..
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chancer
Registered: Apr 2003
Posts: 347 |
mag . i mean 1.30 euros = £1 I just realised doh!
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chancer
Registered: Apr 2003
Posts: 347 |
I just ordered the alignment disk, hopefully it's correct. I don't think it has the instructions if any. If someone has them, can they please leave me a PM.. thanks =)
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ready.
Registered: Feb 2003
Posts: 441 |
dear all,
I recently bought a 1541-II and it had some problems when running demos. For example Edge of Disgrace crashed some times. So I ran the Free Spirit Disk. I checked the head stop position and it gave it was in a bad condition, the head stopped at track 1.
Reading the manual given with the disk, the stop should be just before track 1, showing track 0 on the screen, so let's say track 0.9999999
Then I adjusted a bit the head stop mechanism, so that the program would give me positive result, shwoing track 0 after bump test.
Finally I ran Edge of Disgrace again several times and it worked fine.
Now, this is the second drive I manage to fix just by using the head stop block. Reading around about misalignament, I read that this occurs usually because the shaft of the stepper motor is made of steel but the flywheel driving the head is aluminum. Due to heat and mechanical solicitation (expecially when bumping at track 0) the flywheel slips from the shaft, causing misalignament.
Now, according to my experience, moving the head stop backwards (towards the rear of the 1541), can restore the alignament, re-gaining the track lost during the slipping of the flywheel.
Is there any drawback about this method? It seems so simple to me that I suspect there's something majorly wrong that I am missing.
Ready. |
