Can a Sony video recorder be controlled from an SGI serial port?

[Bill Coughran]

   I have a Silicon Graphics 4D-240VGX running under IRIX 3.3.2 and
have been doing frame by frame animation with a Sony 1" video
recorder (model BVH-2500).  The Sony can be controlled via a 9-pin
RS-422-A input:
	RS-422-A, full duplex, 38.4Kb/s
	1 start bit + 8 data bits + 1 parity bits + 1 stop bit
	odd parity
I have a level converter box that goes from RS-232 to RS-422, which
doesn't look at the pulses and has worked with an older alternate way
of driving the Sony.

   I use the following procedure to set one of the SGI serial i/o ports:

	#include	<termio.h>
	#include	<termios.h>
	
	tsetup(int fd)
	{
		struct termio	tbuf;
	
		if(ioctl(fd, TCFLSH, TCIOFLUSH) < 0)
			perror("ioctl 1");
		if(ioctl(fd, TCGETA, &tbuf) < 0)
			perror("ioctl 2");
		tbuf.c_cflag = B38400 | CS8 | CLOCAL | CREAD | PARENB | PARODD;
		tbuf.c_cc[VMIN] = 1;
		tbuf.c_cc[VTIME] = 5;
		tbuf.c_line = LDISC0;
		tbuf.c_lflag = 0;
		tbuf.c_oflag = 0;
		tbuf.c_iflag = IGNBRK | IGNPAR;
		if(ioctl(fd, TCSETA, &tbuf) < 0)
			perror("ioctl 3");
	}

The Sony complains about a parity error if I then send it control bytes
(that work via my alternate delivery system).

   Has anyone figured out how to control a professional Sony recorder
through a serial port?

		Bill Coughran
		AT&T Bell Laboratories