OFF EOF – As for OFF ERR, turns off above command. The OFF commands are not
required if the program ends normally as both modes are automatically turned
DIR – Displays the directory of the currently logged disk drive. This is shown
in a different format to when displayed under Nas-Dos. Each file name is shown
with the type of file (XBS for XBASIC, OBJ for object code, ASC for ASCII type
files or how you wish to suffix them!) Nas-Dos object code files and ROM
BASIC files are shown with strange file types. Locked files are indicated with
an asterisk in front of the filename and the size of each file is given after
the name to the nearest 1k above its actual size.
LOAD – Followed by a filename loads a file from tape or disk. e.g.
LOAD"TEST" will load the XBASIC program called TEST from the current logged
drive, disk or tape. Any program in memory is lost but variables are not
destroyed. LOAD"B:TEST.OBJ" will load the object code file called TEST from
disk drive B (irrespective of the current logged drive) into memory starting
at the location reserved for it by the CLEAR command.
SAVE – Similar in operation to LOAD command above only, of course, saves the
file to disk or tape. Three types of file may be saved with this direct
command –XBASIC programs, object code and a program as an ASCII file. If the
filename is already present on disk then the file with that name will be
erased before saving the current program!
ERA – Followed by a filename will erase the disk file of that name from the
LOCK – Followed by a filename will lock the file so any attempt to erase or
save a file of the same name will produce an error message. UNLOCK removes the
REN – Followed by two filenames will rename one file for the other.
VERIFY – Followed by a filename will verify the file, reporting any checksum
error as a Bad Data Error.
CHAIN – Followed by a filename will load and execute a program whilst
preserving variables. Particularly useful when used in conjunction with the
HOLD command such that common subroutines at the beginning of a program may be
“held” and then another program CHAINed from disk, an automatic MGE being
performed, the resulting program then being able to make use of the previously
“held” subroutines. Thus any number of programs may be “chained” which make
use of a common set of routines. I find this command most useful.
CREATE – Followed by a valid filename will create a file for subsequent data
torage using the PRINT# command. Random or sequential access are both catered
OPEN – Followed by a filename will open a previously created file for
subsequent writing (PRINT#) or reading (INPUT#).
APPEND – Followed by a filename will open the file for subsequent writing
(PRINT#) or reading (INPUT#).