INT 14 - SERIAL - GET PORT STATUS
AH = 03h
DX = port number (00h-03h) (04h-43h for Digiboard XAPCM232.SYS)
Return: AH = line status
bit 7: timeout
6: transmit shift register empty
5: transmit holding register empty
4: break detected
3: framing error
2: parity error
1: overrun error
0: receive data ready
AL = modem status
bit 7: carrier detect
6: ring indicator
5: data set ready
4: clear to send
3: delta carrier detect
2: trailing edge of ring indicator
1: delta data set ready
0: delta clear to send
SeeAlso: AH=07h"MultiDOS",AH=81h"COURIERS",AX=FD02h

See also: 1400

1403 - SERIAL - GET PORT STATUS