Chapter 8 - Using MS-DOS
PL-5910 Series User Manual
8-23
Next, each function will be explained.
The Line Status and the Modem Status bits are used as follows:
(Each of these bits is enabled when it is "1", and disabled when it is "0")
Line Status
Modem Status
Bit 0
Data Ready
Bit 1
Overrun Error
Bit 2
Parity Error
Bit 3
Frame Error
Bit 4
Break Detect
Bit 5
Transmit's Reserved Register Free
Bit 6
Transmit's Shift Register Free
Bit 7
Time Out Error
Bit 0
Unused
Bit 1
Unused
Bit 2
Unused
Bit 3
Unused
Bit 4
Clear To Send
Bit 5
Data Set Ready
Bit 6
Ring Indicator
Bit 7
Carrier Detect
Function 00h
Initialize Transmission Port
This function performs Transmission Port initialization. Clears the Transmission
buffer.
Input:
AH = 00h,
AL = Port Parameter
Bit 0,1
Data bit length
00: Unsettable 01: Unsettable 10: 7 bit 11: 8 bit (default)
Bit 2
Stop Bit
0: 1 stop bit 1: 2 stop bits (default)
Bit 3,4
Parity
00: NON (default) 01: ODD 10: NON 11: EVEN
Bit 5,6,7
Baud Rate
000:110, 001:150, 010:300, 011:600, 100:1200,
101:2400, 110:4800, 111:9600 (default)
DX = Port Number (0 to 3)
Output:
AH = Line Status,
AL = Modem Status
