Todays Development source snapshot merges in code sent by "zydeco" from his iPhone/iPod Touch port that improves support for the Disk Copy 4.2 disk image format, using information found in the Lisa Emulator Project by Ray A. Arachelian. I´ve also tried adding support for file tags to Mini vMac.

There has been no further progress in Macintosh II emulation since the last snapshot. And I haven´t been keeping up with correspondence. But the good news is that I think I´m gradually getting my health back.

The code from zydeco means that Mini vMac will now get the correct size of the data in a Disk Copy 4.2 disk image, and will identify such an image even if it is not in HFS or MFS format.

Also, with the build system option "-sony-sum 1", Mini vMac will update the checksum in a Disk Copy 4.2 disk image when it is unmounted. This prevents other programs that deal with such images from complaining about an invalid checksum. (I didn´t include this by default, because it makes Mini vMac slightly bigger and slower.)

With the build system option "-sony-tag 1", Mini vMac tries to support file tags. There are an additional 12 bytes for each 512 byte block on a 400K or 800K floppy disk, containing some additional information that was supposed to aid in recovering damaged disks, but was never actually used much. The Disk Copy 4.2 disk image format can support these tags. (The more usual raw format, such as found in Blanks, does not.)

The build system also now has the option "-sony-dc42 0" to completely disable support for disk images in disk copy 4.2 format. This could be useful when trying to compile the smallest and simplest version of Mini vMac possible for some specific purpose. It should not be used when compiling a version of Mini vMac for general distribution, because a primary goal of Mini vMac is that disk images that work with any past version of the program should also work with the current and any future version (at least when default compile options are used).

To make it easier to support file tags, and also easier to make (and debug) other changes, I´ve moved most of the logic of the replacement disk driver out of the 68k code and into the main Mini vMac program. This actually is moving back closer to how vMac works. But it still avoids having the main program try to call back into the 68k code, which I never got to work reliably.

I´ve made a number of small changes to the replacement disk driver that I think make it act closer to original Apple versions. (But which don´t make any known observable difference.)

One more change in this snapshot is that it supports Microsoft Visual Studio 2008 Express, using "-t wx86 -ev 9000" in the build system.