Path: utzoo!utgpu!cunews!cognos!attila!fozzi.ocunix.on.ca!latour!mcr
From: mcr@Sandelman.OCUnix.on.ca (Michael Richardson)
Newsgroups: comp.sys.amiga.programmer
Subject: Re: ASDG DSB DTR control
Message-ID: <1991Jun22.025147.10168@Sandelman.OCUnix.on.ca>
Date: 22 Jun 91 02:51:47 GMT
References: <91171.021857DXB132@psuvm.psu.edu>
Organization: Sandelman Software Works, Debugging Department, Ottawa, ON
Lines: 78

In article <91171.021857DXB132@psuvm.psu.edu> DXB132@psuvm.psu.edu writes:
>This information was posted to the net a while ago, but it slipped by me.
>Could someone with documentation on the ASDG dual serial board describe
>the command extensions defined by ASDG for controlling DTR? I'd like to
>be compatible. Thanks!!!

  My experience is that trying to send characters to the internal
serial port while the DTR is down occasionally crashes serial.device.
It has been awhile since I tried though. There is no problem sending
characters to the ASDG board while DTR is down. 

  From welmat/src/welmat/session/modemio.c:

/* DTR.c -- handle DTR */
/****************************************/
/* Set com DTR line                     */
/* FALSE = DTR off; TRUE = dtr on       */
/* I hate bit bashing.                  */
/****************************************/

SetInternalDTR(fd,set)
MHANDLE fd;
int set;
{
  struct CIA *Ciab;
  char tbuf[20];

#ifdef DTR_DEBUG
  sprintf(tbuf,"DTR is %d\n",set);
  M_DEBUG(M_DEBUG_FATAL,tbuf);
#endif
  Ciab=(struct CIA *)0xBFD000;
  Disable();
  Ciab->ciaddra |= CIAF_COMDTR;            /* Set DTR as output */
  if (set) Ciab->ciapra &= ~CIAF_COMDTR;   /* Set DTR low */
  else Ciab->ciapra |=  CIAF_COMDTR;       /* Set DTR high */

  Enable();
}

/****************************************************/
/* ASDG Dual Serial Board (and presumably 4 board)  */
/*  DTR control support.                            */
/****************************************************/
#define SIOCMD_SETCTRLLINES 0x10
#define SIOB_RTSB  0
#define SIOB_DTRB  1
#define SIOB_RTSF  (1<<SIOB_RTSB)
#define SIOB_DTRF  (1<<SIOB_DTRB)

SetAsdgDTR(fd,set)
MHANDLE fd;
int set;
{
  register IOExtSer *ios;

  ios=&fd->IOutil;

  ios->IOSer.io_Command=SIOCMD_SETCTRLLINES;
  ios->IOSer.io_Offset=SIOB_DTRF;
  if(set==TRUE) {
    ios->IOSer.io_Length=SIOB_DTRF;
  }
  else {
    ios->IOSer.io_Length=0;
  }
  DoIO(ios);
}

/*************************************************/



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