R. T. RUSSELL
BBC BASIC (Z80) Manual
Operating System Interface
As with the BBC micro computer, the star (*) commands
provide access to the operating system. Since the BBC operating system
is completely different to CP/M-80 there are a number of differences
in the star commands.
File specifiers must comply with the standard CP/M-80 conventions.
A: to P: are accepted in file specifications. Filenames in star commands
may optionally be enclosed in quotes; unmatched quotes will cause a
'Bad string' error.
The standard CP/M-80 'wild-cards' may
be used when an ambiguous file specifier is acceptable.
||The single letter name (A to P) of the drive where the
file will be found. The colon is mandatory. If the drive name is
omitted, the currently logged-on drive is assumed.|
||The name of the file. The length of the name must not
exceed 8 characters.|
||The optional extension of the file. If an extension
is used it must be separated from the filename by a full-stop. If
the extension is omitted, .BBC is assumed.|
The following symbols and abbreviations are used as part of the explanation
of the operating system commands.
||Allow any single character in this position. If this
is used as the last character in the name, a null character will be
||Allow any character (including a null) from the position
of the '*' to the end of the name or extension.|
||The enclosed items may be repeated 0 or more times.|
||The items enclosed are optional, they may occur zero
or one time.|
||A numeric constant.|
||A string constant.|
||A numeric variable.|
||A string variable.|
||An ambiguous file specifier.|
||An unambiguous file specifier.|
||A disk drive name.|
||A directory name.|
The star commands
may be accessed directly or via the
OSCLI statement. The two examples
below both access the BYE command.
A star command must be the last (or only) command on a program line
and its argument may not be a variable. If you need to use one of
these commands with a variable as the argument, use the
OSCLI statement. Examples
of the use of the OSCLI statement are given below in the
Resident Star Commands sub-section.
Star commands and their associated qualifiers are converted from lower-case
to upper-case if necessary. For example, *era wombat is converted
to *ERA WOMBAT. This is in keeping with the general CP/M-80
philosophy and the BBC Micro's machine operating system (MOS).
Control characters, lower-case characters, DEL and quotation marks
may be incorporated in filenames by using the 'escape' character '|'.
||A ||gives ^A.|
||a||gives lower-case A.|
||"||gives the quote marks ".|
|||||gives the escape character |.|
||!||sets bit 7 of the following character.|
© Doug Mounter and
Richard Russell 2009