Technical information

NewBIOS Reference Serial Solutions
Service B1H, Get/Set Software Handshake._____________________________________
Compatibility._____________
NewBIOS service only, ignored by PC ROM BIOS.
Parameters.___________
AH = B0H Denotes service B0H
DX = 0...31 Port number, 0=COM1...31=COM32
AL = 00H Denotes read software handshake
mode
AL = 01H Denotes set software handshake
mode, where
BL = 0..1 Mode, as
0 ==> software handshake disabled
1 ==> software handshake enabled
AL = 02H Denotes read XON and XOFF
characters
AL = 03H Denotes write XON and XOFF
characters, where
BL = 0-255 current XON character
BL = 0-255 current XOFF character
Return Values._____________
Subservices 00H and 01H, read/set software handshake:
BL = Software handshake mode as above
Subservices 02H and 03H, read/set XON and XOFF:
BL = XON character
BH = XOFF character
Meaning._________
Chapter 5 Page 97