Closes a file opened by OpenFile().
Handle, DOS handle of the file to close.
None
Reads from a file.
Handle, DOS handle of the file to read from.
Buffer, starting address of the buffer to read into.
Count, (maximum) number of bytes to read into buffer.
Returns number of bytes actually read from the file into the buffer.
Handle, DOS handle of the file to read from.
BufSel, selector of memory segment in which buffer resides.
Buffer, starting address (within the memory segment selected by BufSel) of the buffer to read into.
Count, (maximum) number of bytes to read into buffer.
Returns number of bytes actually read from the file into the buffer.
Writes into a file.
Handle, DOS handle of the file to write into.
Buffer, starting address of the buffer to read from.
Count, (maximum) number of bytes to write into the file.
Returns number of bytes actually written into the file from the buffer.
Handle, DOS handle of the file to write into.
BufSel, selector of memory segment in which buffer resides.
Buffer, starting address (within the memory segment selected by BufSel) of the buffer to read from.
Count, (maximum) number of bytes to write into the file.
Returns number of bytes actually written into the file from the buffer.
Moves current file position (the file position is where reading or writing operations start at).
Handle, DOS handle of the file to seek within.
Count, number of bytes to seek from position specified by From. May be negative to seek backwards in the file.
From, file position to seek from: 0=start of file, 1=current file position, 2=end of file
Returns new file position (in bytes, from start of file), or -1 on error.