83Plus:Software:usb8x/Asm Interface/MSD/DOS fileWrite - Revision history

Brandonw: Oops...function doesn't change attributes

2006-09-12T07:46:54Z

Oops...function doesn't change attributes

Brandonw at 09:15, 17 August 2006

2006-08-17T09:15:49Z

Brandonw at 08:34, 17 August 2006

2006-08-17T08:34:45Z

New page

== Synopsis ==
'''Name:''' DOS_fileWrite

'''Minimum usb8x version:''' 0.10

Writes bytes to a file and grows it if necessary.

=== Inputs ===
* HL points to file handle of an opened file
* DE points to a buffer of bytes to write
* BC is the number of bytes to write

=== Outputs ===
* BC is the number of bytes actually written
* C set if problems

=== Destroys ===
* AF, BC, DE, HL

== Notes ==
Example code to write "This is a test" to "readme.txt" in the root directory:
<code>
ld hl,sFilename
ld de,file_handle
U_CALL DOS_openFile
;HL points to file handle
ld de,sWrite
ld bc,14
U_CALL DOS_fileWrite
...
sFilename: DB "/readme.txt",0
sWrite: DB "This is a test"
</code>
If you are writing an application, you must copy the strings you use to RAM first, or else usb8x will not be able to see them.

== See Also ==
* [[../DOS_fileRead|DOS_fileRead]] - Read bytes from a file at current seek pointer
* [[../DOS_fileSeek|DOS_fileSeek]] - Set seek pointer in file handle

@@ Line 19: / Line 19: @@
 == Notes ==
-The file's modified date/time attributes are set according to the 84+/SE clock. Avoid overuse of this function, such as calling it hundreds of times to write one byte at a time. It is much better to write all hundred bytes at once.
+Avoid overuse of this function, such as calling it hundreds of times to write one byte at a time. It is much better to write all hundred bytes at once.
 Example code to write "This is a test" to "readme.txt" in the root directory:
 <code>