DSKLEN_DMAEN
custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
custom.dsklen = unit[drive].type->read_size/sizeof(short) | DSKLEN_DMAEN;
custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;
custom.dsklen = unit[drive].type->write_size/sizeof(short) | DSKLEN_DMAEN|DSKLEN_WRITE;