Commodore 128D - Page 268

DOPEN
—Open a disk file for a read and/or write operation
DOPEN #logical file
number,"! ilename[,<S |P|U >]"[,Lrecord
length][,Ddrive number][<ON | ,>Udevice
number][, W]
where:
S = Sequential File Type
P = Program File Type
U = User File Type
L = Record Length = the length of records in a relative file only
W = Write Operation (if not specified a read operation occurs)
This statement opens a file for a read or write operation. The record
length (L) pertains to a relative file's record length, which can be as
long as 255. The "W" parameter is specified only during a write
(PRINT#) operation. If it is not specified, the disk drive assumes the
disk operation to be a read operation.
LJ
U
u
u
u
u
The logical file number associates a number to the file for future disk
operations such as a read (INPUT#) or write (PRINT#) operation. The
logical file number can range from 1 to 255. Logical file numbers
greater than 128 automatically receive a carriage return and line
feed with each write (PRINT#) command. Logical file numbers less
than 128 receive only a carriage return, which can be suppressed
with a semicolon at the end of the PRINT# command. The default
device number is 8, and the default drive is 0. The default file type is
sequential and the default operation is READ.
EXAMPLES:
DOPEN#1, "ADDRESS",W Open the sequential file number 1
(ADDRESS) for a write operation
DOPEN#2 "RECIPES",D1,U9 Open the sequential file number 2
(RECIPES) for a read operation on
device number 9, drive 1
U
LJ
u
i {
260
BASIC 7.0 ENCYCLOPEDIA—Basic Commands and Statements
LJ
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