Re: packing disk copy 4.2 disk images for the web?

From: Ray Arachelian <ray_at_email.domain.hidden>
Date: Mon, 23 Apr 2007 11:52:05 -0400

My hypothetical $0.02 if I were to do this, which I can't/wont, for reasons that would jeopardize the emulator project:

  1. I'd put all of a set of related disks together. i.e. LOS3.1 + LOS 3.1 tools in one archive. Why, it's 2007. Bandwidth is plentiful. Requiring a person to click on multiple items for downloading is silly. Separating the tools from the operating system is just silly. It's unlikely that someone would want just the tools or just the OS.

I'd put third party Lisa software, as rare as they may be, in separate archives, however.

I'd even put all of the languages used by LPW in the same archive, and as future archives are found, add them to the existing one, adding a note that this was updated on a specific date adding whatever disk. Again, each virtual floppy is only 400K, much less compressed.

I'd even put Mac the Mac OS floppy along with the MacWorks boot disk. You want something that is known to work well together. If you have multiple versions of Mac OS + tools, add them all in. i.e. MacWorks Boot, System 4, System 5, etc. but don't go crazy building a huge archive of software. (It might be worth it to have a 400K MFS floppy for use on Lisas running MacWorks with archiving/connectivity tools such as StuffIt Expander, CompactorPro, ZTerm, and other useful freeware/shareware available as well since MFS is hard to use on anything running higher than System 6.0.8 - but that should be separate from the MacWorks archives.)

Similarly, I'd pack all of the Xenix files into the same archive. I would not separate out Lyrix, nor the development packages.

2. I'd separate archives by versions as well as product. i.e. LOS3.0 is separate from LOS 3.1, LPW is separated from LOS.

3. For the archive medium, I'd use StuffIt 1.5 as there is open source code to extract from these (google for unsit.c), that way they can be opened by StuffIt or Expander on an old Mac and physical floppies made. StuffIt archives also remove the need for MacBinary II or HQX wrapper as StuffIt/Expander can deal with it anyway.

I would NOT make the SIT files self extracting as this would likely cause trouble on systems other than classic 68K Macs.

4. Before making the SIT archive, I would drop all of the disk images onto FileTyper or similar and set the appropriate creator/type for Disk Copy 4.2.

5. All the disk images should be Disk Copy 4.2. This is important so as to allow the creation of real floppies for use on a real Lisa with the proper number of bit-slip sync bytes. It is fortuitous that the LisaEm prefers this format, however, it can also handle DART images properly. Running DART to restore disk images on a Mac whose formatting routine does not produce the proper bit slip will cause problems for a real Lisa. So, always, always, always stick to Disk Copy 4.2, not DART, not Disk Copy 6.x, not anything else.

Also, unlike DART, Disk Copy 4.2 stores all of its data inside its data fork. DART stores checksum information in a pair of resource forks. To properly ship DART by itself (outside of a SIT archive) would require at least a MacBinary header. Without it the image is broken. If you extract a DART file on a windows or unix machine, the resource fork would be stripped and you would then only be able to use the resulting file with the emulator - you would be unlikely to be able to restore it to a real floppy later on.

Disk Copy 4.2 images will survive being extracted on unix/windows and then being transferred back to a real Mac. You'd need to use FileTyper to reset the Creator/Type file info, but beyond that, it would restore just fine to a real floppy.

6. I would also provide copies (if possible) of StuffIt expander for classic Mac OS, Win32, the unsit.c for unix, Disk Copy 4.2, DART 1.5.x, FEdit, FileTyper, and lisafsh-tool along with the archives.

7. I would also include archives of the ROMs separately. These can be useful not just for the emulator, but also incase someone has a bad EPROM on their Lisa, or has had theirs exposed to too much UV light, etc. This means the I/O and video ROMs as well, and having copies of all the known versions of the ROMs would be helpful. i.e. D,F,H,3A, the 800K floppy ROMs, etc. any Apple II or III software useful for low-level formatting ProFile or Widget drives, and the special ROM to do that, etc.

BTW: ZIP would also be a nice archiving format as every modern system supports it, including OS X. The OS X Finder's Archive command produces ZIP files. The big issue here is that while there are unzipping tools for Classic Mac, they're a bit alien and not as native by default as SIT files, but they do exist.

Again, note that I'm neither encouraging, nor instructing anyone to do any of the above, nor am I suggesting that I would do any of this myself (unless it was legal to do so.) This is all just hypothetical, nothing to see here, move along... if you happen to be a IP lawyer, go and bark up some other tree with deeper pockets than mine. Received on 2007-04-23 11:52:07

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