file types, 9830 with 9880 mass storage

[brouhaha]

The 9830 with the 9880 mass storage system (2.5MB cartridge disks) has three documented file types, "P" (program), "D" (data), and "K" (keys). The file type is stored as the thirteenth byte in each file directory entry, with values 0x20 for data, 0x40 for program, 0x60 for keys. I was really hoping that they'd have a file type for binary files, as they do on cassette tape, but after some experimentation and code disassembly it appears that they do not. It appears that the low five bits of the file type byte are ignored, and that all unrecognized combinations of the high three bits are listed in a catalog with no file type and are not usable by the 9830.