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.