AH = 00h: Initialize Serial Port

This service sets the baud rate, parity, number of stop bits, and character frame size for the specified serial port from data passed in Register AL. The function returns the LSR and MSR registers as shown in the figure below:

• Input: AH = 00h
  DX = Port# (0 = Built-In Serial Port)

• AL = Parameters)

• Output: AH: Line Status

• Output: AL: Modem Status

• Error conditions: None reported
• Registers modified: AX