User`s guide

Function 152 also excludes all control characters from the file fields, and translates all
lower-case letters to upper-case.
Avoid using parentheses and the backslash character, \, in the filename and filetype
fields because they are commonly used delimiters. Use asterisk and question mark
characters, * and ?, only to make an ambiguous file reference. When Function 152
encounters an * in a filename or filetype field, it pads the remainder of the field with
question marks. For example, a filename of X*.* is parsed to X???????.???. The
BDOS search and delete functions treat a ? in the filename and type fields as follows:
A ? in any position matches the corresponding field of any directory entry belonging
to the current user number. Thus, a search operation for X???????.??? finds all the
current user files on the directory beginning in X. Most other file related BDOS
functions treat the presence of a ? in the filename or type field as an error.
It is not mandatory to follow the file naming conventions of CP/M 3 when you
create or rename a file with BDOS functions. However, the conventions must be used
if the file is to be accessed from a command line. For example, the CCP cannot locate
a command file in the directory if its filename or type field contains a lower-case
letter.
As a general rule, the filetype field names the generic category of a particular file,
while the filename distinguishes individual files in each category. Although they are
generally arbitrary, the following list of filetypes names some of the generic categories
that have been established.
ASM Assembler Source PLI PL/I Source File
PRN Printer Listing REL Relocatable Module
HEX Hex Machine Code TEX TEX Formatter Source
BAS Basic Source File BAK ED Source Backup
INT Intermediate File SYM SID Symbol File
COM Command File $$$ Temporary File
PRL Page Relocatable DAT Data File
SPR Sys. Page Reloc. SYS System File
2.3.2 Disk and File Organization
The BDOS file system can support from one to sixteen logical drives. The maxi-
mum file size supported on a drive is 32 megabytes. The maximum capacity of a
drive is determined by the data block size specified for the drive in the BIOS. The
data block size is the basic unit in which the BDOS allocates disk space to files.
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2.3 BDOS File System CP/M 3 Programmer's Guide