[unix-history] / usr / sys / dmr / vt.c

#
/*
 *	Copyright 1973 Bell Telephone Laboratories Inc
 */

/*
 * VT01 driver via DR11C to 11/20
 */

#include "../param.h"
#include "../user.h"

int	vtflag;

struct vtreg {
	int	csr;
	int	buf;
};

#define	VTADDR	0167770
#define	RQINT	01
#define	BIENABL	040
#define	SEOF	0100000
#define	VTPRI	8

vtopen(dev, flag)
{
	if (!flag)
		u.u_error = ENXIO;
	else
		VTADDR->csr = BIENABL;
}

vtclose()
{
	VTADDR->buf = SEOF;
	VTADDR->csr =| RQINT;
}

vtwrite()
{
	register int c;
	int register count;

	while ((c=cpass()) >= 0) {
	    retry:
		for (count=0; count<10; count++)
			if ((VTADDR->csr&RQINT)==0) {
				VTADDR->buf = c&0377;
				VTADDR->csr =| RQINT;
				goto contin;
			}
		spl5();
		if (VTADDR->csr&RQINT) {
			vtflag++;
			sleep(VTADDR, VTPRI);
		}
		spl0();
		goto retry;
    contin:;
	}
}

vtintr()
{
	VTADDR->csr =& ~RQINT;
	if (vtflag) {
		vtflag = 0;
		wakeup(VTADDR);
	}
}
Commit	Line	Data
b74a9dc6 DR	1	#
	2	/*
	3	* Copyright 1973 Bell Telephone Laboratories Inc
	4	*/
	5
	6	/*
	7	* VT01 driver via DR11C to 11/20
	8	*/
	9
	10	#include "../param.h"
	11	#include "../user.h"
	12
	13	int vtflag;
	14
	15	struct vtreg {
	16	int csr;
	17	int buf;
	18	};
	19
	20	#define VTADDR 0167770
	21	#define RQINT 01
	22	#define BIENABL 040
	23	#define SEOF 0100000
	24	#define VTPRI 8
	25
	26	vtopen(dev, flag)
	27	{
	28	if (!flag)
	29	u.u_error = ENXIO;
	30	else
	31	VTADDR->csr = BIENABL;
	32	}
	33
	34	vtclose()
	35	{
	36	VTADDR->buf = SEOF;
	37	VTADDR->csr =\| RQINT;
	38	}
	39
	40	vtwrite()
	41	{
	42	register int c;
	43	int register count;
	44
	45	while ((c=cpass()) >= 0) {
	46	retry:
	47	for (count=0; count<10; count++)
	48	if ((VTADDR->csr&RQINT)==0) {
	49	VTADDR->buf = c&0377;
	50	VTADDR->csr =\| RQINT;
	51	goto contin;
	52	}
	53	spl5();
	54	if (VTADDR->csr&RQINT) {
	55	vtflag++;
	56	sleep(VTADDR, VTPRI);
	57	}
	58	spl0();
	59	goto retry;
	60	contin:;
	61	}
	62	}
	63
	64	vtintr()
65	{
66	VTADDR->csr =& ~RQINT;
67	if (vtflag) {
68	vtflag = 0;
69	wakeup(VTADDR);
70	}
71	}