2/7 Disks Working After Spindle Hub Adjustment- Next Step?

[bobrocks95]

Hi everyone,

I've been trying to get my FDS working off and on since around August of last year after returning from a trip to Japan.

The errors I recall seeing are 21, 22, and 27, so I've focused most of my time on spindle hub alignment, but the best I've ever gotten to is 2 out of my 7 disks/sides working.

What should I look to next in your all's recommendation?  Could the spindle hub still be off even though a couple of games are working fine?

The working games are the simpler ones (Volleyball and Knight Move), but I have what seem to be good condition disks, and 3 of them are retail boxes that came complete.  I find it unlikely that the majority of them are in that bad of shape...

[famiac]

did you replace the belt and adjust the drive speed? clean the read head?

[bobrocks95]

did you replace the belt and adjust the drive speed? clean the read head?

Belt has been replaced and I recall cleaning the read head, but another round of alcohol couldn't hurt.

Will try some drive speed adjustments- I'm guessing that the idea is to turn it one way until it stops reading a known good disk, turn back the other way until it stops reading, and then align it in-between the two settings?

EDIT: cleaned the head again, tried out some drive speed adjustments for ~30 minutes and Knight Move has a really big speed range where it works, while Volleyball I only ever got to read the header block again, which makes me think the real issue likely isn't the drive speed?

[famiac]

drive speed adjustment is really hard if you don't use software that measures the speed like "copy master"

i don't know of any existing homebrew that does the same thing, but that would likely be a better option

[bobrocks95]

drive speed adjustment is really hard if you don't use software that measures the speed like "copy master"

i don't know of any existing homebrew that does the same thing, but that would likely be a better option

Doesn't look like you can just buy a copy master disk anywhere.  I'll keep trying, but it seems like it doesn't really affect any of my disks that were already having trouble being read.

[ericj]

Doesn't look like you can just buy a copy master disk anywhere.  I'll keep trying, but it seems like it doesn't really affect any of my disks that were already having trouble being read.

You can load the ROM if you have FDSLoadr, an FDSStick, or an FDSEmu emulation device. It requires a game doctor copier to work though.

[famiac]

it would be nice to look into making a version of that software to run without a game doctor

[P]

Why does it need the doctor anyway? Does it use hardware in it to measure motor speed? The FDS doesn't have anything like that anyway so I'm not sure how Copy Master is measuring it.

If I just knew how motor speed can be measure I could easily make a homebrew program for it. I could start a thread on Nesdev and see if anyone knows there. FDS stuff tends to be a bit obscure there though.

[ericj]

If you look at the image file, it will probably make sense how it's done. If I had to make a guess, I would think it's reading some (repeating?) data on the disk and deriving speed from that. The program probably only needs the game doctor for the disk copying routine.

Let me know if you need the file and I can send it to you.

[P]

I was afraid of that. I'm not very good at reverse-engineering or disassembling, but I can at least take a look at it.

[ericj]

PM me your email and I'll send it to you.