SCP format - disk type confusion
I'm interested to find reliable way to identify PC SCP disk images and what type these are. (I don't care about non-IBM disk images at the moment.)
Looking at the SCP format description this should be possible by checking Byte 4. But when I look at my SCP images the value is not even close to what I expect and I can see no way to match it up to the documentation...

Here some samples I created at different times using the SuperCard Pro Software. The last sample was created just now after double checking that as format IBM 1.44 had been selected:
  1. 53 43 50 20 45
  2. 53 43 50 23 45
  3. 53 43 50 23 45
I don't get why the disk type is 0x45 when I just created an IBM 1.44 image. Shouldn't it be 0x33?
0x45 would map to DISK CLASS TANDY and an undefined SUB.CLASS. Am I missing something or is the documentation really wrong here?!?

Unrelated but also noteworthy, there is a typo in the tapes section:
tape_MFM = 0x01                    ; xxxx 0010

In context it's more or less obvious that this should be tape_MFM = 0x02
You are correct. I need to look at this ASAP. 0x33 should be generated for IBM PC 1.44MB disks.

Thanks for tip on the typo. I will make the correction.
Thanks for pointing this out! This is a bug that was introduced when I added the MFM hard drive and tape drive support! The spec is correct. I have fixed this today. You can auto-update your SCP software by just running it (it should tell you there is a new version and let you update it), or you can force it to update from the pull-down menu if you have the auto-update feature disabled.
That was fast, thanks!
My ultimate goal is to see if I can add scp image support to qemu, extending the Intel 82078 floppy emulator to handle copy protected disks.

So the bug only affected PC disks? I'm wondering now if I should maybe add some code to handle it correct for old images.
I don't see any version history for the Supercard Pro software. Which version added MFM hard drive and tape drive support?

And what codes would the buggy versions use for the different PC disks?
Yes, the bug only affected PC disks that were created since the hard drive and tape drive support was added.  That was added on 06/16/20.  Considering that SCP will be 10 years old next year I would not worry about trying to make things backwards compatible for the last version.  The reality is that the disk type was designed for programs that might require it.  You can decode any format by just looking at the data, without knowing what type of disk it is.  The data rate can be determined as well as the number of tracks/sides.

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