I have some very old mac floppies (a mix of 400K, 800K and high density). Most of these are so old that they’re corrupt.
Now, when I used to have a mac I could recover data on floppies by using a program which IIRC (and I think I don’t) showed me a bitstream or something which I somehow read with a hex editor and then cut and pasted the text. (Mostly what I have on these was text files - MacWrite generally - so I could live without the formatting).
I no longer have my mac though now. So I’m sitting here wondering if there’s any way to recover any of the data on these floppies using a Windows PC. No program I’ve tried has been able to touch these disks - mac converters say they’re bad disks and windows file recovery programs and hex editors say they’re unformatted disks.
Anybody have any suggestions? I’m thinking there has to be some program out there that can look at the raw bits on these floppies. I’m probably wrong.
Mac Opener by Realviz or MacDisk will open Mac disks on a PC - not if they’re corrput though. You need to find a Mac with Norton Utilities and try one of their programs on the disk to make it readable. Macdisk is about $20, don’t know about Mac Opener. I’ve not tried either, but was looking into it at work today (Was sifting through my mac cds to burn the better artwork onto a PC DVD ROM).
Neither Mac Opener nor MacDisk nor anything else in all of creation will allow a PC to read a Macintosh 800K or 400K diskette. (Should work fine for the hi-density Mac diskettes, though).
The Macintosh 800K diskettes were based on a totally different format, called GCR (hi-density Mac diskettes and PC double-density 720K diskettes are formatted in MFM instead).
Think of a floppy divided up the way you’d cut up a pizza or a cake or pie: wedge-shaped sectors defined by lines that go from the center to the edge in a straight line. The tracks are concentric rings that intersect these lines. Notice that the inner tracks of a given sector consist of far less total area than the outer tracks of the same sector. This format is the MFM format. It is read by a constant-speed floppy drive – the head moves in to the center or out to the edge and reads the information whirling beneath it which spins at the same rate regardless of whether you’re reading the inside track or the outside track or one located somewhere in the middle. PCs can read these and so can Macs.
Now imagine a different way of cutting it up. We’re going to shoot for an arrangement where the inner track sectors consist of pretty much the same total area as the outer track sectors, and the way we’re going to accomplish this is to start off with just a few sectors in the area closest to the center; then as we move out, we’ll cut up the tracks into more sectors, until at the outside edges we’ve got many many sectors. Now, to read this floppy, we’re going to have to vary the speed of rotation of the floppy depending on whether we’re reading a track close to the center (spin faster) or closer to the edges (slow it down). We have to vary the speed because sectors are a linear distance rather than an angular distance under the head, and too many millimeters of outside track would pass under the head in the same interval if we didn’t slow the drive down. This format is called GCR, and Macintosh computers can read them (assuming you’ve got a Mac old enough to still have a floppy drive!) but PC floppy drives cannot because they are fixed-speed drives. As you can see, it isn’t a software issue.
The GCR format requires more expensive drives; the drives sound funny when they are accessing 800K diskettes (the pitch changes, the Mac sings to you!); you get more data on a floppy (800K instead of 720).
For the sake of more compatibility with the PC world, the later floppy drives on Macs were set up to read MFM, and the Mac hi-density standard was MFM just like the PC standard.
The 400 K Mac floppies are single-sided versions of the GCR format. The file system is different from 800K though – the 400K floppies were initialized with a file system known as MFS (Macintosh File System), which is not supported at all by modern Mac operating systems (you can’t even mount a 400K disk image in MacOS 9, for instance). Beginning with the 800K floppy and System 3, Apple switched to HFS (Hierarchical File System). (Mac operating systems prior to 3 cannot read data from 800K diskettes except from their root. Folders are invisible and opaque to MFS and Systems 1 and 2 only knew about MFS!).
If you’d like, I have an aging Mac that can still boot System 7 and has a floppy drive, as well as some old versions of Mac Tools which were very good at rescuing sick floppy disks. I’ll scavenge them for you and send them back to you as Macintosh disk images or burn you a CD.
Well… there’s this place. I recall reading about a program that did almost exactly this, but I can’t find it again!
Closest I can find is this here.. I’d recommend searching the rest of tucows.com.
AHunter3, I’m damn glad to hear from ya. I am the rare commonity that you have heard rumors of…I’m a still employed MACINTOSH geek at a large (over 400) ad agency. I’m the only mac geek left due to all the layoffs, but I have survived.
I still have a working IIsi that wouldn’t have a problem reading those disks, and a crossover cable will give it over to my powerbook in appletalk with not much of a sweat(obviously not 10/100).
You spoke with some authority, so I’m thinking we could possibly pair up as the angels of the board. Due to budget cuts, I currently have 6 Powerbooks (black keyboards) 3 Powerbooks(Bronze keyboard) 4 G3 Blue and Whites, and 2 G4 Graphites that I am cannabalizing just to keep my agency running. As you would expect, I have bad hard drives, bad CD drives, and maybe a bad logic board here or there. The obscure parts are where we need to talk. The company I work for actually has to pay by the pound to get rid of old computer equipment.
Drop me a line, I could reduce the “per pound” price I’m paying, while at the same time helping peeps with older macs.
I’m a gainfully employede Macintosh geek, too, at a printing company. (Most of the other folks here are Mac users too – financial department being the primary exception).
The IIsi was a cute little machine, I remember it well!
I’m not sure what it is that you want to do vis-a-vis our respective collection of vintage Mac parts, though. Sounds like either one of us could rescue uglybeech’s antediluvian floppies.
I myself might conveivably be interested in one of those WallStreet black-keyboard PowerBooks if you have one with lots of unhappy parts but a live screen and logic board. Let me know what you’re thinking though.
Oh, I guess you mean being ‘board angels’ Actually the SDMB community is pretty good overall as far as computer help is concerned, but we might set up shop as the Ask the Vintange Macintosh Geeks people… the ones you go to when you have a CricketDraw question or need help with your LocalTalk network…
Maybe you could try a Kinkos store, they have Macs then you could open those files & email yourself the data? Most schools have old Macs that maybe you could use but I like that idea of using the Kinkos computers to email yourself the data.
The computers in Kinkos won’t read 400K floppies either. You need a Mac old enough to boot System 7 for that, and it has to actually have System 7 loaded on it.
Yeah. With or without modem, an old Mac with System 7 (or even System 6), Disk First Aid, and a floppy drive would be useful. If you can nail an old copy of Central Point’s MacTools, better yet.
Remove contents of 400K floppies to hard drive, then copy to 1.4MB diskette.
