#include #include #include struct termios serialconf; // Retrieve existing configuration via serialfd if (tcgetattr(serialfd, &serialconf) < 0) // Handle error // Modify settings for standard 8N1 (8 data bits, no parity, 1 stop bit) serialconf.c_cflag &= ~PARENB; // No Parity serialconf.c_cflag &= ~CSTOPB; // 1 Stop Bit serialconf.c_cflag &= ~CSIZE; // Clear the current character size mask serialconf.c_cflag |= CS8; // Set 8 data bits serialconf.c_cflag |= CREAD | CLOCAL; // Enable receiver, ignore modem control lines // Set Baud Rate to 115200 bps cfsetispeed(&serialconf, B115200); cfsetospeed(&serialconf, B115200); // Apply configuration immediately tcsetattr(serialfd, TCSANOW, &serialconf); Use code with caution. 3. Data Transmission Operations

By using EPOLLET (edge-triggered), the kernel alerts your application only when new data enters the hardware buffer, minimizing context switches.

: Governs the transmission speed. Both devices must match this timing exactly. Character Size ( CS8 ) : Sets the data word length to 8 bits.

On the DOS side, run serialfd.asm (TSR). It will attach to the BIOS interrupt.