FDD different between 2+ and tR?

Page 1/2
| 2

By wyrdwad

Paladin (928)

wyrdwad's picture

17-03-2021, 20:01

OK, so this is a bit of an odd thing, but it's affected enough at this point that I felt it was worth asking about.

I got into the MSX scene when I imported a Panasonic FS-A1WX (MSX2+) back in 2015, and while it's always had a few issues (a loose/unresponsive controller port, for example), one thing that never gave me trouble with it was the floppy drive. When I bought the system, I was told the drive belt had just been replaced, and that drive has been my gold standard -- if it can't read a disk, then nothing can.

About a half-year ago, though, I managed to score myself a Panasonic FS-A1ST (Turbo R), and it's in nearly perfect condition. Everything feels tight and secure, and is clean and in working order. The auction listing claimed that the system was refurbished 2 years prior and used as a display piece, only being sold because the seller no longer had room to display it.

I've been super satisfied with my ST thus far, and have enjoyed all the benefits it has to offer. However, I've run into one very peculiar issue: its floppy drive seems to be "less powerful" than the one on my WX.

This is where things get weird and hard to explain, but here's the basic gist:

- Some disks that my WX reads just fine simply can't be read by my ST. When I boot the ST with one of these disks inserted, the FDD makes a noise like its motor is struggling, and the system just boots into BASIC, but with the R800 light illuminated on the ST's front panel for some reason. One example of a disk this happens with: a physical retail copy of Eggbert. This same disk is confirmed to load without issue in my WX. This issue has also been confirmed to happen with a small number of blank floppies I've used to write DSK files onto, and again, these disks give me no trouble in the WX or in my USB floppy disk drive that I use with my Windows machine to write the DSKs. Only the ST struggles with them.

- More bizarrely, some disks that my WX reads just fine can't even be inserted into my ST. Like, physically, the ST just won't let me push them all the way in -- when I attempt to do so, it's like there's some force inside the machine actively pushing back, preventing the disk from going in any farther. The disks this happens with don't look like they have any issues -- the metal slider isn't bent or misaligned, and it slides over just fine. Additionally, the middle bit spins without resistance on these disks. Just, for some reason, the tR physically WILL NOT allow these disks inside its drive. One example of a disk this happens with: a physical retail copy of Blade Lords. This same disk is confirmed to load without issue in my WX. This issue has also been confirmed to happen with a small number of blank floppies I've used to write DSK files onto, and again, these disks give me no trouble in the WX or in my USB floppy disk drive that I use with my Windows machine to write the DSKs. Only the ST rejects them.

These issues obviously suggest that there's some problem with my ST's floppy drive, but the thing is, I own a LOT of disks, and 95% of them load just fine on the ST. It's only a small handful of disks that give me trouble, and they ONLY give me trouble on my ST. But nonetheless, the vast majority of disks load and save without the slightest issue, so the ST's floppy drive is by no means broken or worn out or anything.

Best as I can tell, it's just "weak." It's... underpowered? Or something.

So my questions are:
1) Can anyone give any explanation as to why these issues might be occurring? Is this the sort of thing that happens when a belt is starting to wear out, for example?
2) Absolute worst case scenario, I was thinking of maybe trying to swap floppy drives between my two machines to see if maybe I can get the "I'll read anything" drive of the WX functioning in the ST... but is that feasible? Do the two machines use the same model of floppy drive, or are they incompatible with one another? Would you recommend this, or is this just a Very Bad Idea?

Thanks, for any insight anyone can provide!

-Tom

Login or register to post comments

By st1mpy

Paladin (736)

st1mpy's picture

17-03-2021, 20:35

I have a wx and a st too. I haven't used the fdd enough to notice. The drives might not be the original ones, and as you say the belt might be going. If the belt is replaced with a non standard one, it is possible to end up with a drive that can read data it wrote but not written on another machine. Its probably worth replacing the belt or the drive.

By Meits

Scribe (6350)

Meits's picture

17-03-2021, 20:50

The original drives are the same.

By wyrdwad

Paladin (928)

wyrdwad's picture

17-03-2021, 20:58

Hmm, OK. I don't think it's anything quite that drastic, since again, it's able to read the vast majority of disks, both commercial and written. But it still may have something to do with the belt, so replacing it is probably not a bad idea. Can you direct me to a resource that would tell me what kind of belt I should look for to replace it with?

Before attempting something as drastic as swapping drives, changing out the belt seems like an easier, safer thing to try.

Thanks to you both for the quick replies!

-Tom

By Meits

Scribe (6350)

Meits's picture

17-03-2021, 21:33

Changing drives is easier than swapping belts I think. I can't check because none of my units have the original drive anymore (belt being reason no. 1)

By st1mpy

Paladin (736)

st1mpy's picture

17-03-2021, 21:36

May be worth checking the power as well, does it need 12v? May be capacitors are going. I guess if you end up swapping the drives (if the belt change doesn't work) it will be revealed (that drives are ok but power is bad).

I think changing the belt might be harder than swapping the drives.

By Meits

Scribe (6350)

Meits's picture

17-03-2021, 21:45

The only thing that makes it last a bit longer is that you can not swap the brackets on which the drives are mounted. But nothing technical there. Just screws.

By wyrdwad

Paladin (928)

wyrdwad's picture

18-03-2021, 05:41

Yeah, I'll be honest, I haven't opened up the Turbo R *at all* yet since purchasing it, since the previous owner said it was fully refurbished and tested/working before selling it to me, and it's thus far been completely reliable on all fronts EXCEPT for this small handful of disks it struggles with.

I do think it's more likely to be the drive itself, though, than any capacitors, if only because one of the biggest issues is disks that physically can't be inserted into the drive for no apparent reason. Obviously there must be some issue with the metal slider on those particular disks not quite being properly aligned or something, but regardless, it's not going to be a capacitor issue that causes the drive to physically reject certain disks. Wink

I wish I knew why it did that, though. It's just such a strange phenomenon! I've never heard of such a thing happening before, and it's just really odd that my Windows USB floppy drive and my WX's floppy drive can accept and read those disks without issue, but I can't even fit them into my ST.

I should try to record a video sometime showing this, as it truly is bizarre.

-Tom

By gdx

Enlighted (4255)

gdx's picture

18-03-2021, 08:32

Meits wrote:

The original drives are the same.

No, they are a little different.
https://www.msx.org/wiki/Panasonic_FS-A1WX
https://www.msx.org/wiki/Panasonic_FS-A1ST

I have roughly the same issue. Some floppy disks have trouble reading. They make a noise and seemed to have difficulty turning. If I put a floppy disk that works and then put a problematic one back, it works again for a while. I changed the belt but it doesn't change anything.

By wyrdwad

Paladin (928)

wyrdwad's picture

18-03-2021, 08:56

gdx wrote:
Meits wrote:

The original drives are the same.

No, they are a little different.
https://www.msx.org/wiki/Panasonic_FS-A1WX
https://www.msx.org/wiki/Panasonic_FS-A1ST

I'm not seeing any indication of this in these wiki articles. In fact, both of them say the respective systems use the same floppy disk controller: Toshiba TC8566AF.

I don't doubt that the drives are at least marginally different (if nothing else, they're differently colored!), but if the two systems use the same floppy disk controllers, that should mean the drives themselves can be swapped and should still function in the other system, no? Or are they differently sized, have different motors, etc. that might stand to cause problems?

I just want to make sure I don't damage my system(s) by swapping drives, should I decide to try it somewhere down the line.

-Tom

By mars2000you

Enlighted (5833)

mars2000you's picture

18-03-2021, 09:03

wyrdwad wrote:

I'm not seeing any indication of this in these wiki articles. In fact, both of them say the respective systems use the same floppy disk controller: Toshiba TC8566AF.

Compare the pictures!!!

https://www.msx.org/wiki/File:Fsa1wxi.jpg

https://www.msx.org/wiki/File:Fsa1stj.jpg

Page 1/2
| 2