Trouble Initializing/Writing 400k (Single Sided) Disks on a PowerBook 3400c Running 7.6

[SilverStreaks]

I am trying to write an image to a 400k single sided disk, but I just can't get it to work. Every program I've tried returns errors, listed below:

Disk Copy 4.2	An error (-81) occured while copying/verifying the disk
Disk Copy 6.3.3	The Make Floppy operation did not complete. (-81)
ShrinkWrap 3.5.1	A media problem has been found on this volume. The disk may be copy-protected or damaged. Error #-81
DiskDup+ 2.9.1	Initialize Failed!

The disks are from a company called Dysan and came in a sealed box. I've tried all 10 disks, and they all fail. I find it difficult to believe that the disks themselves are faulty. Anyone got any ideas?

 

[3lectr1cPPC]

Not sure whether you can write 400k disks or not on a system that new - someone will confirm on that.

But first the obvious: Does the drive work with known-good disks?

 

[SilverStreaks]

Not sure whether you can write 400k disks or not on a system that new - someone will confirm on that.

But first the obvious: Does the drive work with known-good disks?

Unfortunately I don't have any other disks to try it with. I know this is probably the bottleneck here, but I want to see what else I could do while I wait for some working disks to be delivered.

 

[3lectr1cPPC]

Ah, well it's probably likely that your drive is bad then. Not too uncommon to see. Try with some 800K or 1.44MB disks once you get them.

 

[SilverStreaks]

Ah, well it's probably likely that your drive is bad then. Not too uncommon to see. Try with some 800K or 1.44MB disks once you get them.

Bummer. Would a dirty r/w head be a possibility here?

 

[3lectr1cPPC]

Could be that, or a locked up stepper motor, or any number of failures. Does the drive sound normal when attempting a format?

Could also be a box of bad disks though. It's not at all uncommon to see that, if the box was stored poorly.

Also again, not entirely sure if there's a software limitation there as 400k disks are pretty early.

 

[Forrest]

I never had much luck using 400K/800K disks when my preG3 PowerMacs were new, much less 25 years later. Apple had phased out 400K/800K drives in Macs around 1988. If you want to use floppies, the 1.4 MB HD disks are a lot more reliable.

 

[Mk.558]

Any machine with a built-in floppy drive or compatible external (i.e. PB1400) can write a 400KiB disk image file but systems beyond 7.6.1 cannot read them. Mac OS X machines (not sure about OS X Server) cannot use the internal drive.

Error code -81 means you have a sector error. Either the disk is bad, the image is corrupted, or the floppy drive needs some maintenance.

I would suggest loading the disk image in Mini vMac and checking for its integrity that way, and based on that, you may have to make a new image file by copying the contents out to a blank 400KiB MFS image. Use System 6 for doing this.

While it is true that "2MB" "high density" disks do have stronger magnetic flux than 720KiB/800KiB/837KiB/880KiB/360KiB/400KiB disks do, they're not necessarily more reliable. In a pinch, a high density disk can be used to substitute for a 800KiB disk but it isn't ideal -- but is an option, which will likely work best if it wasn't formatted as any other format beforehand.

 

[bigmessowires]

Are your Dysan disks double-density or high-density?

 

[SilverStreaks]

Any machine with a built-in floppy drive or compatible external (i.e. PB1400) can write a 400KiB disk image file but systems beyond 7.6.1 cannot read them. Mac OS X machines (not sure about OS X Server) cannot use the internal drive.

Error code -81 means you have a sector error. Either the disk is bad, the image is corrupted, or the floppy drive needs some maintenance.

I would suggest loading the disk image in Mini vMac and checking for its integrity that way, and based on that, you may have to make a new image file by copying the contents out to a blank 400KiB MFS image. Use System 6 for doing this.

While it is true that "2MB" "high density" disks do have stronger magnetic flux than 720KiB/800KiB/837KiB/880KiB/360KiB/400KiB disks do, they're not necessarily more reliable. In a pinch, a high density disk can be used to substitute for a 800KiB disk but it isn't ideal -- but is an option, which will likely work best if it wasn't formatted as any other format beforehand.

Thanks for the tip! So far it seems that the disk images themselves are totally fine. I'm trying to write a system disk for my Macintosh 512k. So at this point its either the drive or the disks themselves, will have to find out by testing with known good disks.

 

[SilverStreaks]

Are your Dysan disks double-density or high-density?

Double density.

 

[SilverStreaks]

Could be that, or a locked up stepper motor, or any number of failures. Does the drive sound normal when attempting a format?

Could also be a box of bad disks though. It's not at all uncommon to see that, if the box was stored poorly.

Also again, not entirely sure if there's a software limitation there as 400k disks are pretty early.

To me it sounds nominal, but I'm not really sure what its supposed to sound like.

 

[bigmessowires]

Maybe review this old thread. It sounds like 400K disk support after System 7.0 was pretty glitchy.

If the drive is formatting the disk normally, you should hear 80 evenly-spaced clicking sounds or vibrations, grouped into 5 sets of 16 with a short pause between each group. That's writing the tracks, and adjusting the rotation speed after every 16 tracks. Then after a short pause you should hear 80 more clicks or vibrations, but coming about twice as fast as before. That's verifying the tracks. Finally after a slightly longer pause, you should hear some uneven clicks and grunts for a couple of seconds. That's writing the initial disk directory. Once that's done, the newly-formatted disk should appear on the Finder desktop. If your drive doesn't make it through that whole process, then it might help to identify exactly when it's failing.

 

[mg.man]

I've created loads of 400k disks - even some for my Lisa - on System versions up to 9.x. I'm wondering - even though NOS/sealed - if it might be your diskettes? Have you tried formatting them as regular - 800k - diskettes?

ISTR reading somewhere that sometimes the magnetism just gets messed up, and that waving a bulk tape eraser over can bring old diskettes back to life. I've never tried, so YMMV!

 

[Mk.558]

If you're just trying to install stuff, one option is to use the network.

Using a System 3.3/Finder 5.4 network access disk, you could copy all the contents of the disks to a RAM disk on another machine which is shared out to the LocalTalk network. As long as you have two floppy drives, you can then use the shared volume as the installation source while you install onto a second floppy drive. TBH any machine without a hard drive of sorts really should have a second floppy drive: with the 512K, you can use a 400KiB MFS boot floppy with Appleshare WS 1.1, screen saver and the usual stuff like File Tools DA. Then after it loads the HD20 INIT you could use a 800KiB external drive as your system disk or something.

 

[SilverStreaks]

Hey guys sorry for the late response,

I ended up finding a huge box filled with over a hundred floppy disks for $20! I was able to successfully write to the disks from there, so it turns out the ones I had before were indeed bad. Quite a few of the disks from the new box were also bad, but started working again after running them through a few times. So that has me wondering if there might be a way to revive old disks by blindly writing over them multiple times. Is there any program that does this?

 

[3lectr1cPPC]

Also possible that your heads were a bit stiff and using them more loosened them up and got them running better.

 

[SilverStreaks]

Also possible that your heads were a bit stiff and using them more loosened them up and got them running better.

Perhaps, but my old disks still won't initialize, neither on my Macintosh 512K nor 3400c. So I'm guessing just bad disks.

 

[3lectr1cPPC]

Probably the case then.