Copy protected Excel 1.00 - now what?

I've added Microsoft Excel 1.00 for Macintosh, but it is copy protected, and I don't have a Mac of the appropriate vintage to test with.

https://winworldpc.com/product/microsoft-excel/1x

The only mac emulator that I even know of that supports copy protection is PCE-Mac. I've gotten as far as converting to a PRI, and setting PCE to emulate a Mac 512k (what is needed to run this program). The software gets as far as loading the program in to memory and then it complains that I need to insert the Excel Master disk.

There was hardly a clue on the web that Excel 1.00 was ever copy protected. Later versions were not.

It has two intentionally bad sectors, one on track 02 and another on track 03. The contents appear to fluxuate, perhaps using weakbits. No idea what kind of GCR/IWM futzing was possible on early macs.

There are Kryoflux images, SuperCard pro images, and TransCopy images (although I don't think anything supports TransCopy Mac images). I would be interested to know if anyone can create a working disk from these.

Unfortunately, I'm low on time, so I'll just have to leave this to others to figure out.

Comments

  • Just out of curiosity, how do you determine that the bad sectors are intentional? I'm new to all of this stuff.

    I was just trying to image an old school mac floppy, and I came across some bad sectors. I thought it might have been a dirty disk (and therefore drive) so I cleaned the drive and still had the same bad sectors. I was wondering if I had a bad disk or perhaps it was copy protection.

    I then used a completely different drive, and came up with a different set of bad sectors. I've never experienced anything like that before. I ended up taking the raw files from both drives, and combining just the good sectors into one folder and then running kryoflux on the stream files. When I did that I got all green, and I was able to make the image work in BasiliskII.

    So now I'm wondering if some drives just don't like mac formatted floppies.

  • So I used a 3rd drive, and I got green boxes everywhere. So I'm guessing that's the drive I'm using for 400K/800K mac floppies from now on.

  • Macintosh 400k/800k floppy disks use variable bitrates. On a genuine Mac, it spins at different speeds depending on the track.

    Many IBM PC 3.5" drives have built in density filtering and automatic gain control that incorrectly filters out parts of the signal. In these cases, exactly what part of the disk appears "bad" depends on the specific drive.

    Teac and Toshiba drives seem to get the best results. But no PC drives are absolutely perfect with this. Macs are goofy :P

    I determined that tracks 02 and 03 were copy protected by viewing the histogram in the Kryoflux GUI. I could tell the signal looked good, except for a very distinct "bad" pattern that exactly fit evenly over one entire sector.

    Also, since there was a second backup disk, I determined that the the copy protection was exactly identical on both disks.

  • +1 for using TEAC drives for Mac floppies. That's the only luck I've had. Neither my NEC or my Sony drives have worked.

  • I was using a Sony and Samsung when I had issues. The drive that worked well for me was a Mitsumi. Those were the only drives I've got that aren't in computers right now.

  • I'll give this a try on a Citizen drive I've got using the KF and Supercard images.

  • I’m afraid I’ve derailed this a little by talking about drives :)

    I think the most important thing is testing it on a real Mac, if you have one.

  • Yes, I'm a little uncertain exactly what it is looking for in those two artificially bad sectors, so any testing would be very welcome.

    It is clearly not just looking for a "bad" sector, it seems to be looking for something specific. My hunch is it is messing around with the IWM (mac disk controller) somehow, so it could be doing something extra odd.

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