System information

default buffer: Default 128-byte buffer maintained at 0080H in page zero. When the CCP loads
a COM file, this buffer is initialized to the command tall; that is, any characters typed after the
COM file name are loaded into the buffer. The first byte at 0080H contains the length of the
command tall, while the command tail itself begins at 0081H. The command tail is terminated by
a byte containing a binary zero value. The I command under DDT and SID initializes this buffer
in the same way as the CCP.
default FCB: Two default FCBs are maintained by the CCP at 005CH and 006CH in page zero.
The first default FCB is initialized from the first delimited field in the command tail. The second
default FCB is initialized from the next field in the command tail.
delimiter: Special characters that separate different items in a command line; for example, a
colon separates the drive specification from the filename. The CCP recognizes the following
characters as delimiters: . : = ; < > - , blank, and carriage return. Several CP/M commands also
treat the following as delimiter characters: , [ ] ( ) $. It is advisable to avoid the use of delimiter
characters and lower-case characters in CP/M filenames.
DIR: Parameter in the diskdef macro library that specifies the number of directory elements on
the drive.
DIR attribute: File attribute. A file with the DIR attribute can be displayed by a DIR command.
The file can be accessed from the default user number and drive only.
DIRBUF: 128-byte scratchpad area for directory operations, usually located at the end of the
BIOS. DIRBUF is used by the BDOS during its directory operations. DIRBUF also refers to the
two-byte address of this scratchpad buffer in the disk parameter header at DPbase + 8 bytes.
directory: Portion of a disk that contains entries for each file on the disk. In response to the DIR
command, CP/M displays the filenames stored in the directory. The directory also contains the
locations of the blocks allocated to the files. Each file directory element is in the form of a
32-byte FCB, although one file can have several elements, depending on its size. The maximum
number of directory elements supported is specified by the drive's disk parameter block value for
DRM.
directory element: Data structure. Each file on a disk has one or more 32-byte directory
elements associated with it. There are four directory elements per directory sector. Directory
elements can also be referred to as directory FCBs.
directory entry: File entry displayed by the DIR command. Sometimes this term refers to a
physical directory element.
disk, diskette: Magnetic media used for mass storage in a computer system. Programs and data
are recorded on the disk in the same way music can be recorded on cassette tape. The CP/M
operating system must be initially loaded from disk when the computer is turned on. Diskette
refers to smaller capacity removable floppy diskettes, while disk may refer to either a diskette,
Appendix H : Glossary CP/M Operating System Manual
H-7