User`s guide

2.3.6 Directory Labels and XFCBs
The BDOS file system includes two special types of FCBS: the XFCB and the
Directory Label. The XFCB is an extended FCB that optionally can be associated
with a file in the directory. If present, it contains the file's password. Note that
password protected files and XFCBs are supported only in the banked version of
CP/M 3. The format of the XFCB follows.
Figure 2-1. XFCB Format
dr - drive code (O - 16)
file - filename field
type - filetype field
PM - password mode
bit 7 - Read mode
bit 6 - Write mode
bit 5 - Delete mode
** - bit references are right to left,
relative to 0
sl,s2, rc - reserved for system use
password - 8-byte password field (encrypted)
reserved - 8-byte reserved area
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2.3 BDOS File System CP/M 3 Programmer's Guide