Setup for MFM 5 1/4" DD 360K

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Guld
Posts: 12
Joined: Fri Dec 29, 2017 11:38 pm

Setup for MFM 5 1/4" DD 360K

Post by Guld »

I am trying to setup Kryoflux to read images using my old 5 1/4" double density drive from a PCjr (so MFM format). I am having some trouble getting the correct configuration options so that I get a valid image once it is done. For my test disk, when I put my drive in the actual computer with the same disk, the disk works fine. I can run the program and get a valid directory listing, etc. However, I haven't had much luck getting Kryoflux setup to get an image where I can even see a valid directory tree.

Any advice on what settings I should use? I've set the RPM to 300 as I believe these old DD drives were 300 RPM and it calibrates to 41 tracks maximum, which makes sense. Any other settings I should use?
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by brightcaster »

Is this related to your first posting here?

viewtopic.php?f=3&t=1366&p=12486#p12486

If yes, than you should not use -k2 and replace -e83 with -e41 as you already dump with a 40 track (48tpi) drive....

David
Guld
Posts: 12
Joined: Fri Dec 29, 2017 11:38 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by Guld »

Not exactly, that was when I was imaging everything using a high density drive years back. Now I am trying to do similar with my only working double density drive. The track is set to 41 tracks maximum for this particular drive (same value I get after calibration).

I have been using the GUI for testing so I'm not sure of the exact command line equivalents for the settings I have right now. On the GUI, I've set it to MFM sector image, everything default except "track distance: 40". I also tried playing with the RPM between 360 and 300. My understanding is 300 should be correct, or so I thought.
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by brightcaster »

You have to uncheck the 40track option if you read with a 40 track (48tpi) drive! Otherwise double stepping will be active (dumping only the even tracks of your floppies). Yes it's a bit misleading...

If you dump a 40track floppy (48tpi) with a 80track drive (96tpi) you have to dial 40track mode. But if you dump a 40track floppy (48tpi) with a 40 track drive (48tpi) you have to dial 80 track mode! It's because the Kryflux was not designed to be used with 40track drives (although it works great)!

David
Guld
Posts: 12
Joined: Fri Dec 29, 2017 11:38 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by Guld »

David, thanks for the pointer! So I guess that setting is more of a setting of whether or not it should skip over every other track (e.g. DD disk in a HD drive).

I'm still having some difficulty getting a good image. The only non-default setting I'm doing now is to set the RPM to 300 and I've also tried 360. AFAIK the drive is 300 RPM, so it should be set to 300?

The best I've gotten so far is for it to have a ton of bad sectors on side 0 (tracks 00-10), but side 1 reports all good. Does the RPM setting matter or is that only for creating the IMG file and is irrelevant to the preservation stream? I see brief glimpses of errors about "drive speed proble...". The output image is also 720 kB instead of the expected 360 kB.

Does density line low/high play into this at all? That setting always confused me a bit to be honest.

And this also leads to one other question I have. Is there any need for me to re-image my DD disks with my DD drive if I previously did them with my HD drive? I was hoping I could possibly recover a little more data from some of the more troublesome disks but maybe this is a lot of effort which likely won't help?
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by brightcaster »

If one side is fine and the other shows many bad sectors it's likely a dirty head or surface. So a good cleaning of head 0 (bottom side) may solve the problem. If the surface of floppy side 0 (bottom side) is molded you see the same results.

300 rpm is correct. You have to add -oe39 to the "other params" field in the setup menu to limit the output to 360k.

David
Guld
Posts: 12
Joined: Fri Dec 29, 2017 11:38 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by Guld »

Thanks David so..

I cleaned the heads, fortunately I still have an old disk cleaning kit and had some 90% isopropyl around. Still no luck. Disks are clean and free of any signs of any surface issues. As noted above, all the disks I have tried so far also read just fine with this same exact drive put in the actual system, so I figure I must be doing something wrong. I have tried multiple disks now and none really seem to give anything useful.

I did a dtc -c3 and the RPM came out to an average of about 301, is that close enough to 300?

I've switched to the command line, can you tell me if these are the correct settings to be using? I guess I could always try to up the retry count.
5 1/4" DSDD drive (360k MFM image)
dtc -ftest.img -i4 -dd0 -v300 -oe39 -pg1 -e41

For some reason, this is still outputting 720k images. This is with Kryoflux for Windows 3.00. -oe should take care of that??? That is odd.

I may have to pull out a HD drive and see how it fares on the same disk. Is there any benefit to pulling a stream with both drives, or is just getting on that works usually sufficient to have the best luck recreating the disk?
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by brightcaster »

Yes, a stream file would be of much help in this case. The rpm doesn't matter much, the software does correct a much greater difference. DD drives don't care about the density line so -dd0 and -dd1 should give the same result...

David
Guld
Posts: 12
Joined: Fri Dec 29, 2017 11:38 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by Guld »

So:
dtc -ftest.img -i4 -i0 -v300 -oe39 -e41

Should give me a preservation stream and a IMG file, correct? I didn't have much luck with this last time I tried, same results. I could share the stream if it helps determine what is going on.

Any idea why the output image is 720k instead of 360k? I'm surprised the -oe didn't fix that.

I'll also try putting the drive back in the system and make sure everything is still working as expected there while I'm at it.
brightcaster
Posts: 476
Joined: Fri Nov 08, 2013 10:48 pm

Re: Setup for MFM 5 1/4" DD 360K

Post by brightcaster »

Your parameter line doesn't work that way! Just to quote the manual:
IMPORTANT NOTE on command line parameters order:
The following settings are “image local” and therefore must appear before the image type and would affect only the first image type specified after the parameter. Their values automatically revert to the default after an image type setting (ie once they get used).

Correct: DTC.exe -ffilename.ext -v360 -z3 -i4
Wrong: DTC.exe -ffilename.ext -i4 -v360 -z3
So your parameter line should be

dtc -ftest.img -v300 -e41 -oe39 -i4 -ffilename -i0

instead of

dtc -ftest.img -i4 -i0 -v300 -oe39 -e41

Still, a raw flux dump would be handy to examine for the bad sectors you get...

David
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