Category : Files from Magazines
Archive   : CGAZ3-1.ZIP
Filename : SERIAL.C

/*********************************************************************
* File: serial.c (part of TTYTALK)
* Author: Victor Volkman
* Date: June, 1988
********************************************************************/
#include "tty.h"

extern struct serial_def serial;

int iobase;
int r_errs;
int q_errs;
QUEUE inq;


void comm_setup()
{
union REGS r;

r.h.ah = 0; /* Set comm parameters */
r.h.al = (serial.ibaud_rate<<5) + (serial.parity<<3) +
(serial.stopbits<<2) + (serial.data);
r.x.dx = serial.adapter;
intsoff();
int86(RS232_INT, &r, &r); /* BIOS communications */
intson();
}


int rcv_char()
{
r_errs += (inp(iobase+LINE_STATUS) & RCV_ERRS) != 0;
return (int) inp(iobase+RCV_DATA);
}


int chk_xmt()
{
return (int) inp(iobase+LINE_STATUS) & XMT_RDY;
}


void xmt_char(chr)
int chr;
{
outp(iobase+XMT_DATA,chr);
}


void send_char(chr)
int chr;
{
while (!chk_xmt());
xmt_char(chr);
}


void send_dial_string(str)
char *str;
{
while (*str != '\0') {
if (*str=='|') /* xlate as CR */
send_char(CHAR_CR);
else if (*str == '^') { /* xlate ctrl char */
send_char(toupper(str[1]) - 'A' + 1);
str++;
}
else if (*str == '~') /* wait 1 second */
wait_tick(18);
else /* actual char */
send_char(*str);
str++;
}
}


void xmt_brk()
{
int ctl;

ctl = inp(iobase+LINE_CTRL) | SET_BRK_BIT;
outp(iobase+LINE_CTRL, ctl);
}


void end_brk()
{
int ctl;

ctl = inp(iobase+LINE_CTRL) & (~SET_BRK_BIT);
outp(iobase+LINE_CTRL, ctl);
}


void send_brk(ticks)
int ticks;
{
xmt_brk(); /* set BREAK bit */
wait_tick(ticks);
end_brk(); /* clear BREAK bit */
}


void wait_tick(clocks) /* wait for specified number of ticks */
int clocks;
{
union REGS r;
long now, end;

r.h.ah = 0; /* Read time of day */
int86(TICK_INT, &r, &r); /* BIOS time of day */
now = r.x.cx<<16 + r.x.dx; /* compute ticks since midnight */
end = now + clocks;
while (now < end) {
r.h.ah = 0;
int86(TICK_INT, &r, &r); /* BIOS time of day */
now = r.x.cx<<16 + r.x.dx;
if (r.h.al) now += 1573040L; /* Rollover clock after midnight*/
}
}