I have a PowerBook 150 running 7.mumble. I want to be able to read/write/format 400kB MFS disks so that I can test MFS support on another platform. Does anyone know of any extensions that add full MFS support, including being able to format them? (Depending on the MacOS version I _may_ have read-only support, but as I don't have any MFS disks to play with I can't test that.)
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Extension supporting 400kB MFS disks?
- Thread starter hjalfi
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olePigeon
Well-known member
I can say with confidence that 7.1 Pro has read support for MFS. You can pseudo write by making a disk image first, then writing the disk image to disk.
An MFS extension would be exceptionally useful, but I've never seen one.
One alternative would be to dual boot your PowerBook with System 6. I think there are Control Panels that allow for easy switching between different versions of Mac OS. But I don't know if it's compatible with System 7 and 6.
An MFS extension would be exceptionally useful, but I've never seen one.
One alternative would be to dual boot your PowerBook with System 6. I think there are Control Panels that allow for easy switching between different versions of Mac OS. But I don't know if it's compatible with System 7 and 6.
3lectr1cPPC
Well-known member
I'd think that System picker would work for that
System Picker - Macintosh Garden
System Picker allows you to choose which System Folder to boot from, if you have 2 or more System Folders on the Macintosh startup disk. Top DL: System Picker version 1.1a3 from 1997 (from Apple Dev CD, Oct 1998). 2nd DL: System Picker version 1.0b11 from 1991. 3rd DL: System Picker version...
olePigeon
Well-known member
@Phipli Good point. @hjalfi Might have to do the Disk Image trick I mentioned earlier if you want to modify and change MFS disks around. It's a pain in the butt, though.
There was a chap who was backporting HFS+ to System 7. I don't recall who it was. But it might be worth asking them if it's possible to do the same with MFS. Make a file system extension for System 7+.
There was a chap who was backporting HFS+ to System 7. I don't recall who it was. But it might be worth asking them if it's possible to do the same with MFS. Make a file system extension for System 7+.
3lectr1cPPC
Well-known member
Ah, I had missed that this was on a 150, otherwise I would have caught that.
Phipli
Well-known member
Do you have a scsi drive and cable? You could install it from a CD or SCSI2SD or whatever. I can't remember the last time I installed 7.* from floppy disks
Phipli
Well-known member
For reference, this site is handy regarding what systems do what with MFS :
Note this :
If you want to format MFS disks on a PB150, you must install 7.1.1 to 7.1.3.
Working with Macintosh Floppy Disks in the New Millennium
Discussion of Apple Macintosh MFS and HFS floppy disks, with emphasis on usage in modern times.
siber-sonic.com
Note this :
If you want to format MFS disks on a PB150, you must install 7.1.1 to 7.1.3.
That's useful, thanks. Looks like I'll be reinstalling, then.
BTW, on a semi-related topic, I am now capable of reading and writing files directly from and to HFS-formatted Mac 800kB floppies on a normal PC drive (connected to a FluxEngine or GreaseWeazle controller). I'd like to add MFS support, at least read-only.
BTW, on a semi-related topic, I am now capable of reading and writing files directly from and to HFS-formatted Mac 800kB floppies on a normal PC drive (connected to a FluxEngine or GreaseWeazle controller). I'd like to add MFS support, at least read-only.
cheesestraws
Well-known member
Oh, that's cool. Another use for the Greaseweazle beckons...
...and that's the hard bit, right?
I've looked at the MFS file system definition; it's not actually very complicated. There's a single directory containing a flat list of files, a single FAT containing the allocation chains, and a boot block. Subdirectories are faked in the main directory --- each file points at the directory entry of its enclosing directory. It's very reminiscent of the CP/M filesystem! https://wiki.osdev.org/MFS
So, providing that the System 7 filesystem extension API is reasonable, I'd guess it'd take someone who knew what they were doing under a week. A read-only version could probably be hacked together in a couple of days. Naturally, I have no idea what the API actually looks like.
olePigeon
Well-known member
@hjalfi I think @cheesestraws started a thread about how to write an Extension file. Plus, I think there's an old tutorial on how to make a Control Panel (which is very similar in many ways.) Plus the numerous copies of "How To Program C On the Macintosh" floating around. That's the one I was playing with for quite a while.
One of the big problems, however, is that all the official reference material is written in Pascal.
One of the big problems, however, is that all the official reference material is written in Pascal.
cheesestraws
Well-known member
Writing an extension is easy: it's literally just a function that gets called at some point in the boot sequence, which can then hook other things. An example of an absolutely trivial extension is this one, which just implements the M1 notch on System 7: https://github.com/cheesestraws/softnotch
Writing a filesystem is harder. Probably the easiest option to take would be to write something against the File System Manager API, which is present in 7.5+. I do not know that API at all, I've never used it, but there's an ext2 implementation with source here that might be a feasible starting point for learning it:
macintoshgarden.org
Writing a filesystem is harder. Probably the easiest option to take would be to write something against the File System Manager API, which is present in 7.5+. I do not know that API at all, I've never used it, but there's an ext2 implementation with source here that might be a feasible starting point for learning it:
MountX - Mount old Linux ext2 filesystems - Macintosh Garden
MountX is a GPL-licensed system extension which provides read-only access to ext2-formatted filesystems, under MacOS 8 & 9 This software is based on e2fsprogs version 1.14, it was written by Benjamin Herrenschmidt, the original author of BootX, a well known Linux bootloader, for PowerPC Macs...
Wow. That's remarkably straightforward. Although, the FSM API looks remarkably complicated. I also found Retro68, which provides a modern development environment (with C++17!) far MacOS. I don't think the FSM bindings could be used as-is with Retro68 but adding them to the Multiversal dataset doesn't look hard.
So, this is definitely doable. I'll admit that there would be a certain satisfaction in writing the thing with MPW on my PB150, though. Also, I have too many projects already...
So, this is definitely doable. I'll admit that there would be a certain satisfaction in writing the thing with MPW on my PB150, though. Also, I have too many projects already...
cheesestraws
Well-known member
Personally, I've stuck to using CodeWarrior Pro rather than retro68, but that's mostly because wrestling gcc is too much like what I do for a day job...
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