Is my FDS compatible with FDSStick?

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Pokun
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Re: Is my FDS compatible with FDSStick?

Post by Pokun »

I see, it's just a theory. I don't know either, maybe magnets are perfectly safe to tapes and QDs physically.

If a disk has already been written with a misaligned disk drive will it be cleared properly even if rewritten with a properly adjusted drive if it misses the old spiral when clearing the data? Maybe a magnet can fix that. Ah I guess that's exactly what you were saying...
I wonder if a magnet can clear a tape cleanly though and not just write a bunch of random data to the disk.

NewRisingSun wrote: Tue Jun 07, 2022 12:43 pm
So in theory perhaps you could copy a disk file by file instead of some kind of raw-diskcopy?
If you are talking about copy protection, then only block type #1 is checked.
Well if block 1 can't be written with a file-per-file copy method, the disk can't be rewritten with another game that requires a different block 1 I suppose.
wes44
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Re: Is my FDS compatible with FDSStick?

Post by wes44 »

Pokun wrote: Mon Jun 06, 2022 8:07 am Yes at least that's what people have reported (I only have one drive myself so I can't check). Basically if another drive should be able to read the disk it must be tweaked similarly to the one that wrote the disk, but even if you succeed in doing so it may not work with official disks anymore.
I'm not sure why this is the case, but I guess the disk drives used in the FDS are cheaper than those used in the Disk Writer kiosks as the FDS drives are only meant to read disks and write to single existing files, so it was enough if they could read what the Disk Writers and factories produced.
When dumping prototype disks people were required to do careful tweaking until these disks could be read.

Some people have claimed in the past that it is possible to tweak an FDS drive to the point that it writes disks correctly like the Disk Writer, but the trustworthiness of those sources are doubtful, and no one has shown any kind of proof or shared the techniques required to do so.


So rewriting disks are basically only useful if you have a disk that is bad anyway or has been rewritten by someone else, and the disk should probably be marked as rewritten for the future. Please don't flood the FDS market with useless disks.
Hello! Sorry to drag up an old thread but I thought the following might be useful.

This problem you mention is only due to incorrectly calibrated disk drives. Provided the drive is calibrated correctly then a disk written by a home famicom disk unit will be readable in other working drives no problem.

The disk drive in the famicom disk writer that used to be in game stores used the same drive that is in the retail FDS.

I have a non licenced zap disc duplicator machine somewhere in storage that uses two regular famicom disk sytem drives but the duplicates used to work on all famicom disk systems with working drives.

Anyway most of the information online is written by people who are "tweaking" things until it seems to work again without knowing what they are doing properly... this has been the case for some decades now so you have a lot of famicom drives that are no longer in very good order.

Most of the guides fixate on spindle alignment.. and then possible a lot of "tweaking" to get the thing to work right.. this is the WRONG approach.

There is a correct 0 position to set the spindle when assembling the drive, but because these are mechanical drives with a certain amount of tolerance this alone is not adequate and fine adjustment is done by adjusting the position of the read head.

Instead of an alignment and calibration what most people seem to be doing is after reassembly moving the spindle arbitrarily until a valid read signal is pass from the drive to the ram adapter with no clear idea on how strong the signal is (giving a representation of how well the drive head is aligned with the data track).. the drive has some tolerance to alignment, an incorrectly calibrated drive will often have intermittent read errors.. it will also write a disk that often cannot be read correctly by a drive in calibration.

Lets assume you totally disassemble a drive, clean and re-grease it, replace the electrolytic condensers and the drive belt and check the felt pad is still ok then you should perform the following steps.

1. set spindle to initial position, this will ensure the the start of the spiral is in the correct place when the read head starts to make the disk pass
2. adjust the read head position via adjustment screw using oscilloscope.. the test point is easily accessed via a cut out in the lower drive cover place, you don't need to have the drive disassembled for this. ideally you want a calibration disc or in the real world a store bought factory written disk should be adequate.. you don't want to try and align the drive to any disks written by drives of unknown calibration unless you are deliberately trying to dump a previously undumped game that wont read on a conventional drive. (advanced)
3. confirm motor speed is correct.. the famicom has good tolerance for speed errors and this adjustment rarely stops a drive from working but its good practice.. starting from the center position if unknown should produce a result the famicom can work with as a starting position.. chris covells famicom disk lister 2 software will show you the read data rate of the disc system and can be used to fine tune the alignment speed without specialist software.

hope that helps... if you need some more information I have a batch of drives coming in for service in the next couple of months.. I always do a complete strip and rebuild on them but can throw one purposely very out of alignment and make a video showing the correct steps to calibrate the drive and then write some discs with it afterwards and load them on other famicom disk systems?

finally nintendo literature says the drives have a finite life.. 40,000 cycles if I remember correctly but I have never seen one yet that was worn out to the point of being unsuable. oh and any drive with a serial number higher than d100000 is most likely to contain some kind of copy protection as mentioned in earlier posts... maybe one of the revised power boards or even the revised drive chips... these need to be modified to write a full disk.
Pokun
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Re: Is my FDS compatible with FDSStick?

Post by Pokun »

No need to be sorry, thank you for this wonderful information. This is the most detailed explanation I've seen so far.

So you need a scope... Coincidentally I've been in the hunt for one lately.

I assume Chris Covell's Famicom Disk Lister 2 can just be loaded via the FDSStick and once loaded, swap the FDSStick for the disk drive so there is no need to write Chris Covell's disk first?

Oh a detailed video guide how to do this properly would be super fantastic. If it's good enough, maybe it could be included on the Nesdev wiki.
NewRisingSun
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Re: Is my FDS compatible with FDSStick?

Post by NewRisingSun »

That recommendation goes against what everybody else has written. The consensus is that the head screw, once properly adjusted at the factory, does not need re-adjusting, and that attempting to do so creates more problems than it solves, which is why the head screw is fixed with some glue-like substance.

The motor speed is mostly of relevance when writing Game Doctor disks, which put up to 66 KiB of data onto a disk side. As a result, the Makko Copy Master (Makko being the company that sold the Game Doctor) provides a motor speed adjustment functionality.
Pokun
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Re: Is my FDS compatible with FDSStick?

Post by Pokun »

Ah yeah that's right, generally people say that the screw with glue on only needs to be tweaked if a previous owner already messed with it (the glue blob is destroyed), but also that it may eventually need to be tweaked at some point due to aging of the parts, but definitely not as part of a normal repair.
ednauseum
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Re: Is my FDS compatible with FDSStick?

Post by ednauseum »

I have repaired well over 100 FDS drives and I have never once needed to adjust the head - like others have noted, it is set at the factory (well, was set there many years ago) and should never need adjusting. I have never found the need to adjust one.

As was also mentioned earlier, on the gear assembly, there are numerous markings that one can use to calibrate to factory settings. As far as speed goes, to me, you should have a sense of normal operation by observation. I can usually tell if the drive speed is off and can micro-adjust the speed of the motor and dial it in. I do have a disk doctor and whatever the disk is that will give you the speed of the motor, I think count from like 1 to 9 where people have noted ~5 is the right speed. I rarely use that though.

My test disks include a factory disk, a disk from a disk re-writer and a crappy Chinese bootleg (the best BTW - Burgertime that starts you with 99 peppers :D ). If I can get a machine to read all three of those, I call it case closed and button up the system. Never had an issue with this method.

All this to say, calibration of any FDS after belt replacement should only take you 10 minutes, if that, to have perfect calibration. I can dial in speed, if necessary, within that timeframe...maybe 1/3 of the systems I see need a little speed adjustment.

As for writing disks with "regular" FDS drives that can be read universally - it is possible. What do you think was used in the rewriters back in the day? They had the same FDS drives that the home systems had.

On a repaired machine that has the right circuitry on the drive and the right version of the power board, you can re-write disks all day long. If you have calibrated the drive and dialed in the speed correctly, you can write a disk that can be read by just about any FDS out there.

Of course I have seen some really bodged repairs, calibration is off, etc. where reading these disks may not work. But in those cases, fixing the mistakes on the target drive will then allow it to read those disks as well. This is always the biggest issue when you write a disk, you cannot know that the target drive has been repaired correctly, unless you fixed it yourself.
wes44
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Re: Is my FDS compatible with FDSStick?

Post by wes44 »

ednauseum wrote: Sun Jul 24, 2022 8:19 am I have repaired well over 100 FDS drives and I have never once needed to adjust the head - like others have noted, it is set at the factory (well, was set there many years ago) and should never need adjusting. I have never found the need to adjust one.

As was also mentioned earlier, on the gear assembly, there are numerous markings that one can use to calibrate to factory settings. As far as speed goes, to me, you should have a sense of normal operation by observation. I can usually tell if the drive speed is off and can micro-adjust the speed of the motor and dial it in. I do have a disk doctor and whatever the disk is that will give you the speed of the motor, I think count from like 1 to 9 where people have noted ~5 is the right speed. I rarely use that though.

My test disks include a factory disk, a disk from a disk re-writer and a crappy Chinese bootleg (the best BTW - Burgertime that starts you with 99 peppers :D ). If I can get a machine to read all three of those, I call it case closed and button up the system. Never had an issue with this method.

All this to say, calibration of any FDS after belt replacement should only take you 10 minutes, if that, to have perfect calibration. I can dial in speed, if necessary, within that timeframe...maybe 1/3 of the systems I see need a little speed adjustment.

As for writing disks with "regular" FDS drives that can be read universally - it is possible. What do you think was used in the rewriters back in the day? They had the same FDS drives that the home systems had.

On a repaired machine that has the right circuitry on the drive and the right version of the power board, you can re-write disks all day long. If you have calibrated the drive and dialed in the speed correctly, you can write a disk that can be read by just about any FDS out there.

Of course I have seen some really bodged repairs, calibration is off, etc. where reading these disks may not work. But in those cases, fixing the mistakes on the target drive will then allow it to read those disks as well. This is always the biggest issue when you write a disk, you cannot know that the target drive has been repaired correctly, unless you fixed it yourself.
Incorrect.

I think I already wrote above that the disk writer uses the same drive as the retail unit, as do the aftermarket copy boxes so writing a disk that can be used in other devices from a home unit is no problem (this was answer to originally quoted users post)

However, while you may have repaired over 100 disk drives and achieved successful results it is NOT the correct procedure.

To say the head is set and never requires adjustment is to not understand how the drive works nor the correct alignment procedure.

This is why it involves trial and error... the people at mitsumi factory assembling the drives did not use trial and error and certainly not sit there and move spindle back and forth until it "works". They used an oscilloscope to set the head so it gave the acceptable signal level from the disk spiral. It is necessary due to mechanical tolerance between not only gears but spindle placement too.

As I wrote originally the tinkering method of slightly changing the spindle position (which is the common guide on the internet) and appears to be what you are saying is correct in order to correct for disk read failures is due to not having re-adjusted the head and thereby moving the start of the spiral slightly to account for the previous head position.

IF the method you speak of was correct then why after following mentioned marking do most guides say if / when you get read errors to move the spindle gear until it work?

You can certainly get a drive to read a disk this way but it takes longer than needed, involves trial and error and you have no way of verifying how well the drive is performing.

What kind of calibration procedure would give alignment markings then require trial and error to get the thing to work?

Instead you are doing only half the procedure and then moving the spiral to the previous head alignment by messing with the spindle where you should move the head to the spiral (assuming you set the 0 position correctly).

When you say "perfect calibration". How do you measure and record that? what constitutes a pass or fail?

The famicom will load data successfully even when the drive has quite poor performance, this is more noticeable when writing or copying a disk as other correctly calibrated drives will often fail to load such disk.

I don't think it is possible to visually distinguish between 423rpm and 407rpm without test equipment or software yet the famicom will still load data from both settings due to its range of tolerances, shouldn't we be aiming for optimal performance?

The post assembly alignment service bulletin gives a range of acceptable voltages from the head amplifier circuitry, the famicom will still load data with a lower signal value but depending on how far off the alignment is it can be more prone to errors saving or loading data.

Assuming the drive is not mechanically damaged in some what then set the spindle head and adjust the read head and drive speed should take around 1 minute and will read all disks correctly everytime, no trial and error just adjust to x setting.
wes44
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Re: Is my FDS compatible with FDSStick?

Post by wes44 »

NewRisingSun wrote: Sat Jul 23, 2022 12:41 pm That recommendation goes against what everybody else has written. The consensus is that the head screw, once properly adjusted at the factory, does not need re-adjusting, and that attempting to do so creates more problems than it solves, which is why the head screw is fixed with some glue-like substance.

The motor speed is mostly of relevance when writing Game Doctor disks, which put up to 66 KiB of data onto a disk side. As a result, the Makko Copy Master (Makko being the company that sold the Game Doctor) provides a motor speed adjustment functionality.
hello!

Yes it seems to be, but (refer to my previous post)..

most of the information online appears to be to "tweak" this until it works with no understanding of how or why it is working after "tweaking"... If you think about things what kind of alignment procedure requires trial and error after with no measurable results?

adjusting the head screw without proper measurement materials is as bad if not worse than arbitrarily tweaking the spindle positions.

The headscrew has paint on it to secure the screw from vibration and to notify the worker that alignment has been completed

The correct voltage output from the disk head can be measured in certain amount of mv p-p with an oscilloscope connected to the test point.

Once the drive and gears have been assembled correctly the head should be moved to match the spiral, which can be done in an easily measureable / repeatable controlled way that takes under a minute with recordable results (head output mv) as opposed to the prevalent method of trial and error until the famicom loads a game.

following the factory procedure I can repair and service / calibrate a drive without ever needing a famicom disk system attached and be 100% sure if the alignement passes when connected to a famicom it will load and save data correctly... can any other of these internet proecdures claim such thing?

I don't think they can becuase even setting the spindle to the 0 position mechanical tolerances and previous factory alignment often dictate that somebody will have to trial and error to get the drive to read and have no way of measuring how good the signal is.

I will make a video next month when I have some more drives to repair... strip / repair rebuild and calibrate without a famicom and then connect to a famicom afterward and get load / save first time / disk copy work first time etc.
Pokun
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Re: Is my FDS compatible with FDSStick?

Post by Pokun »

This whole thread is all about how the usual trial and error method is probably the cause of badly rewritten disks, so you are definitely on to something, and I think using an oscilloscope sounds like a safe way to find the most centered position if you know what the signal should look like. But I'm still wondering if this can't be done without touching the glued head alignment screw?
Unless that's really the official way to do it and the way that Nintendo's repair guys used.
wes44
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Re: Is my FDS compatible with FDSStick?

Post by wes44 »

Pokun wrote: Mon Jul 25, 2022 11:33 am This whole thread is all about how the usual trial and error method is probably the cause of badly rewritten disks, so you are definitely on to something, and I think using an oscilloscope sounds like a safe way to find the most centered position if you know what the signal should look like. But I'm still wondering if this can't be done without touching the glued head alignment screw?
Unless that's really the official way to do it and the way that Nintendo's repair guys used.
Yes that is almost correct.

The head screw isn't glued though. it is a low strength lacquer / varnish with red dye that is used to both visually confirm that the alignment stage was completed and to secure the screw against movement from vibration, very much like the azimuth alignment screw on a cassette deck.

Ordinary nail varnish will serve as a replacement after alignment.

And yes it is almost same as the nintendo service procedure.. after service / repair and rebuild the drive it is tested with an oscilloscope at the test point to measure the alignment, depending on a pass/fail value the drive is either finished or requires head re-alignment.

Many times any drive will appear to work first time for reading disks if you replace the belt and correctly align the gear mechanism, unless you measure it though you have no clue on how well it is aligned only the fact that it seems to load game.. if this is your only endpoint then it is probably ok.. even with correct alignment some drives will not just work right away.. maybe its a good thing as it prevents more people making counterfeit games.

The trial and error method will get the drive reading again as is evident but without any meaningful measurements there is no guarantee on how well the drive is aligned so disk duplication / error free read success cannot be guaranteed..

if using trial and error you may end up with a drive that struggles to read some disks / requires removal and re-insertion of the disk a few times until it works.

Most of this is moot point these days as disk duplication and sharing is pretty much non existent and majority of the people who still use an FDS system do so with emulator or just one drive, so even if the alignment is off any disks they do write are often only used on the drive that wrote them.

The correct procedure might help people who are repairing their drive though and want it to work properly as it left the factory without spending time guessing things or even those who still like to use actual media and have more than one system.

99.9% of the information on the internet is all copied and repeated from the same original source

Also if you have a drive somebody has messed about with before.. i.e. tightened the head alignment screw fully and not put the gears together properly I would imagine trial and error might take a long long time before it even loads a game compared to some minutes with the correct procedures.

Remember.. The disk drive was originally hand assembled, there are always slight variations between drives due to spindle placement, gear backlash etc which is why after assembly the head has to be adjusted to the correct position..

when reassembling a drive, even following the correct gear train alignment you have no guarantee that the position is identical to before you disassembled... if it is close then the drive will probably read and save disk.. maybe some trial and error.

I will make a video anyway for anyone who is interested to learn how to calibrate a drive correctly so that is not only loads a game but you can be sure that it will duplicate correctly too, requires no famicom or trial and error to complete.
Pokun
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Re: Is my FDS compatible with FDSStick?

Post by Pokun »

Sounds reasonable to me.

Yeah counterfeits is a big problem with the Disk System. The fact that there are people selling games they write, recreating labels, cases and obi is a big problem if you want to collect original disks, it's just too hard to tell apart the real ones from the fakes.
This is also problem for preservation, far from all versions of every licensed game has been dumped AFAIK.

The poor information might help preventing the market from being flooded with forgeries, but also that more and more disks will be incorrectly written on poorly serviced drives. I'm generally for keeping information open to the public as the best way to arm people against the bootleggers, and I think that generally the bad guys already has the same information as the good guys anyway.

One thing that saves the Disk System is its relatively low popularity compared to ROM cartridges, which are much more often faked.
Another thing are the wonderful disk drive emulators like the FDSStick, which allows us to play on real hardware without bothering too much with disks and their problems, allowing more room to collectors. Emulators goes here too.
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