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Writing files to 400K floppies using System 7.5.5

decle

Member
Hey all,

I wonder if you can help me please? Could someone test whether it's possible to copy a single file to a formatted 400K floppy in a 1.4MB drive using a 68K Mac running System 7.5.5?

I have an SE/30 with 16MB of RAM that runs System 7.5.5, and I'd like to use it to write 400K disks for a 128K Mac. I believe that this should work, and indeed I can successfully write disk images using DiskCopy 4.2. I can also read files from 400K disks without problem. However, trying to write individual files to a 400K disk fails with a -2 error (I believe this may be a vTypErr, caused by an invalid queue element?!?). It seems as though the copy might actually work, as the available space falls by the expected amount, but perhaps System 7.5.5 cannot update its view of the MFS contents as the number of items on the drive does not increase and no icons appear. Another clue that this is the problem might be that when I view a 400K floppy the icons are screwed up and all over the place (for example the floppy's System Folder is not present and it's contents are scattered in the root folder).

This is definitely a problem with the OS, as if I boot from a System 6.0.8 floppy everything works fine.

Thanks for any help or guidance.
 
Last edited:

Crutch

Well-known member
I can’t explain your -2 error, but the missing folders/scattered icons is normal. That happens because 7.5.5 no longer knows how to interpret the old ‘FOBJ’ folder-proxy setup used on MFS disks (which don’t, of course, have true ‘folders’ in the HFS sense). Any MFS disk loaded under 7.5.5 will not show you any folders.
 

volvo242gt

Well-known member
I seem to remember that being an issue with System 7.1 as well.

I'll have to create another 400K disk and see what happens on my IIci.

Anyway @decle, if your SE/30 has a large enough hard drive, use the System Picker application with a 6.0.8 install that has the Desktop Manager extension installed. That way, you can dual boot the machine and not have the 7.5.5 finder crash when it tries to rebuild the desktop file that 6.0.8 would otherwise create. Then, you'll be able to deal with the 400K disks without having to switch back and forth between floppies, or use an external floppy drive.
 

decle

Member
Thanks for your responses

the missing folders/scattered icons is normal

Good to know, thanks.

I seem to remember that being an issue with System 7.1 as well.

I'll have to create another 400K disk and see what happens on my IIci.

That would be great if you could. I might consider downgrading to System 7.1 if it fixes the problem, although I do like the quality of life improvements associated with 7.5.5.

Anyway @decle, if your SE/30 has a large enough hard drive, use the System Picker application with a 6.0.8 install that has the Desktop Manager extension installed.

This is a great tip, thanks! I had noted the desktop rebuilds, but hadn't linked them with the switch to 6.0.8 and back. I've tried both System Picker 1.1 and System Switcher 1.1.1. Both work a treat, and once Desktop Manager is installed the rebuilds seem to be banished.
 

decle

Member
A small update, although a vanilla install of System 7.0 does not understand MFS folders, it does seem to be able to write files to a 400K disk successfully.
 

volvo242gt

Well-known member
Sounds like the break may've been with 7.1 or 7.5, then. I still need to try 7.1 and see if it works. The hard drive in my Centris 650 decided to commit suicide, so won't be able to do much until that's replaced. Both the IIci and SE still need some help, floppy drive-wise, to get them reading and writing disks perfectly.
 

decle

Member
Fiddling a bit more with a stock 400K MFS disk image of System 2.0 in Basilisk II using Disk Copy 6.3.3...

7.0.1 - Does not render the folder correctly, but files can be copied into the image.
7.1 - Disk Copy whinges when mounting the image (-43 error), but does copy files into the image without error
7.5.3 - Disk Copy gives error -43 on mounting the image, file copies result in an error -3 and disk space consumption
7.5.5 - Same as 7.5.3

In all cases files can be copied and deleted from the 400K image. The gradual degradation of behaviour is interesting. I guess Apple stopped formally supporting MFS at System 7.0 and any residual utility was more luck than judgement.

I've bitten the bullet and ordered a RaScsi. Once I've gotten it set up I'll repeat the tests on real hardware, as there are clearly some small differences in the error codes I'm seeing in Basilisk vs my SE/30.
 

decle

Member
Well the RaSCSI has arrived :), man those 74LS641s get warm! :unsure:

Anyway, with a fresh install of each of the version of MacOS trying to interact with a real 400K disk in the 1.4MB drive of my SE/30 I see...

6.0.8 - Renders the disk fine, including understanding the System Folder and works fine
7.0.1 - Also renders fine and works fine
7.1 - Also renders fine and works fine
7.5.3 - Renders the disk fine, but gives a -5 error when copying a file onto the disk
7.5.5 - Renders the disk fine, but gives a -5 error when copying a file onto the disk

It's a bit strange that the v7.0.1 installed from the Apple restore CD image is better behaved than the 7.0 install I did from floppies. Otherwise it does seem that everything should be OK up to System 7.5.x.

And with the RaSCSI, I now have a convenient mechanism to get data between my SE/30 and desktop PC. (y)
 
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