Category : OS/2 Files
Archive   : OS2TERM.ZIP
Filename : OS2TERM.C

/*
* OS2TERM.C - An interrupt-driven OS/2 terminal emulator
*
* This program uses OS/2's COM0x.SYS serial device
* driver to turn a PC into a simple terminal. Incoming
* data is buffered in OS/2's 1,024-byte serial receive
* queue and transferred to the program's data space
* using wait-for-something reads. DTR and RTS are asserted
* but no handshaking is performed with the RS-232 control
* pins. Execution is terminated when ESC is pressed.
*
* Compile and link with: cl -Lp -G2 -Zp os2term.c
*
* Copyright (c) 1989 Ziff-Davis Publishing Co.
* Written May 1989 for PC Magazine by Jeff Prosise
*/

#define INCL_DOS
#define INCL_SUB
#define INCL_DOSDEVICES

#define SERIAL 0x01
#define SETBAUDRATE 0x41
#define SETLINECTRL 0x42
#define SETDCBINFO 0x53
#define GETDCBINFO 0x73

#define STACK_SIZE 2048
#define BPS 9600
#define KBD_HANDLE 0
#define VIO_HANDLE 0

#include
#include

struct {
unsigned char DataBits;
unsigned char Parity;
unsigned char StopBits;
} LineCtrl = { 8, // 8 data bits
0, // No parity
0 }; // 1 stop bit

struct {
unsigned short usWriteTimeout;
unsigned short usReadTimeout;
unsigned char bFlags1;
unsigned char bFlags2;
unsigned char bFlags3;
unsigned char bErrorReplacementChar;
unsigned char bBreakReplacementChar;
unsigned char bXONChar;
unsigned char bXOFFChar;
} DCBInfo;

unsigned short hCom; // COM handle
unsigned char InBuffer[256]; // Input buffer

/*
* The primary thread opens and initializes the COM
* driver, starts a thread to monitor the serial port,
* displays and outputs characters typed at the keyboard,
* and terminates when ESC is pressed.
*/

main()
{
unsigned short usAction;
unsigned short usBaudRate = BPS;
unsigned ThreadID;
USHORT x, y;
static char ComThdStk[STACK_SIZE];
struct _KBDKEYINFO KbdData;
unsigned short usBytesWritten;

void far ComThread();

/* Open and initialize COM1 */

if (DosOpen("COM1", &hCom, &usAction, 0L, 0, 1, 0x12, 0L)) {
printf("COM1 not available or COM0x.SYS not loaded\n");
exit(1);
}

/* Set data rate to 9600 bps and line format to N81 */

DosDevIOCtl(0L, &usBaudRate, SETBAUDRATE, SERIAL, hCom);
DosDevIOCtl(0L, &LineCtrl, SETLINECTRL, SERIAL, hCom);

/* Set Device Control Block parameters */

DosDevIOCtl( &DCBInfo, 0L, GETDCBINFO, SERIAL, hCom);

DCBInfo.usWriteTimeout = 6000; // 60 second write timeout
DCBInfo.usReadTimeout = 6000; // 60 second read timeout
DCBInfo.bFlags1 = 0x01; // Enable DTR
DCBInfo.bFlags2 = 0x40; // Enable RTS
DCBInfo.bFlags3 = 0x04; // Wait-for-something reads

DosDevIOCtl(0L, &DCBInfo, SETDCBINFO, SERIAL, hCom);

/* Create a thread to monitor the serial port */

DosCreateThread(ComThread, &ThreadID, ComThdStk+STACK_SIZE);

/* Monitor the keyboard and output typed characters */

do
{
KbdCharIn(&KbdData, IO_WAIT, KBD_HANDLE);

if ((KbdData.chChar != 0) && (KbdData.chChar != 0x1B))
{
VioWrtTTy(&KbdData.chChar, 1, VIO_HANDLE);
DosWrite(hCom, &KbdData.chChar, 1, &usBytesWritten);
}

} while (KbdData.chChar != 0x1B);

DosExit(EXIT_PROCESS, 0);
}

#pragma check_stack (off) // Disable stack checking

/*
* This thread monitors COM1 for incoming bytes and writes
* any it receives to the display screen. If an error is
* returned by DosRead(), the thread terminates itself.
*/

void far ComThread()
{
unsigned short usBytesRead;

while (!DosRead(hCom, InBuffer, 256, &usBytesRead))
if (usBytesRead)
{
VioWrtTTy(InBuffer, usBytesRead, VIO_HANDLE);
}

DosExit(EXIT_THREAD, 1);
}