Here’s a brief follow-up about the classic Macintosh game Dark Castle, which I mentioned a few weeks ago in connection with some possible disk emulation bugs. This game originally shipped on two 400K floppy disks. At the intro screen shown above, the player is given a choice of doors, and some of the doors will ask the player to insert disk 2. But when loading the 400K game disk with a Floppy Emu disk emulator, the disk swapping doesn’t work. Disk 1 doesn’t get ejected, and if disk 2 is inserted, it will be ignored. A few weeks ago I speculated that this may be caused by a Floppy Emu bug, but I was wrong.

After a bit of research, I found that the problem is just another example of Games That Only Work In Drive 1. This is pretty common in the Apple II world, but not so common for Macintosh games. When Dark Castle tries to eject disk 1, it specifically tells drive 1 (the internal drive) to eject, regardless of which drive contains the disk. Then it checks the same drive for disk 2. Since Floppy Emu is normally connected to classic Macs as the external drive (drive 2), this doesn’t work. To confirm this behavior, I disassembled an old Mac and connected a Floppy Emu internally, in place of the built-in floppy drive. With this configuration, Dark Castle 400K worked fine.

BMOW’s Vintage Apple Software Collection SD Card has an 800K version of Dark Castle, where the contents of both 400K disks have been copied onto a single 800K disk. This avoids the need for disk swapping, so the game can be played normally from a Floppy Emu or other external floppy drive, but it requires a Macintosh model that’s compatible with 800K drives. The oldest Macintosh models are only compatible with 400K drives. For those models, playing Dark Castle will require connecting the Floppy Emu internally as I did, or copying the disk images from the Floppy Emu onto real 400K disk media for use in the internal floppy drive.