Register parameters

IN:
     A = byte to be written to file / device
     IX = handle of file, device

OUT, if call successful:
     Fc = 0
OUT, if call failed:
     Fc = 1
     A = error code:
          RC_HAND ($08), bad handle
          RC_WP ($14), write protected
          RC_ESC ($01), escape, if device is :COM.0, :PRT.0
          RC_TIME ($02), if device :COM.0, :PRT.0
          RC_ROOM ($07), memory full on current device.

Registers changed after return:
     ..BCDEHL/IXIY same
     AF....../.... different

Notes

Handle is acquired from GN_Opf (or OS_Op for internal use).

Related calls

GN_Cl, close file
GN_Del, delete a file from memory
GN_Opf, open file/resource (wildcard search)
GN_Ren, rename file
OS_Cl, internal close (OZ usage)
OS_Del, file delete (internal OZ usage)
OS_Frm, file read miscellaneous
OS_Fwm, file write miscellaneous
OS_Gb, get byte from file (or device)
OS_Gbt, get byte from file (or device) with timeout
OS_Mv, move bytes between stream and memory
OS_Op, internal open (OZ usage)
OS_Pbt, write byte to file, device with timeout
OS_Ren, file rename (internal OZ usage)