The OTFOC patch THE 'OPENTYPE FILE OPEN/CLOSE' ROUTINE This routine opens or closes an opentype file according to the contents of the A register. When it holds 0 a "D" channel is attached to the stream given in the DFCA. A non zero value closes the corresponding stream. This routine was added in System 3d. 0287 OTFOC AND A 0288 JP Z,#1261,OPEN_CHAN Open a channel if A holds zero. 028B JP #140C,CLOSE_STRM Otherwise close the stream.