Specifications

MICROPROCESSADORES
INTERRUPÇÕES
5
Luís Miguel Charrua Figueiredo 5 - 10 E.N.I.D.H.
AL = modem status (see #00305)
Notes
: default handler is at F000h:E739h in IBM PC and 100% compatible
BIOSes since the PCjr supports a maximum of 4800 bps, attempting to set 9600
bps will result in 4800 bps various network and serial-port drivers support the
standard BIOS functions with interrupt-driven I/O instead of the BIOS's polled I/O
the 1993/04/08 Compaq system ROM uses only the low two bits of DX the default
setting used by DOS (MS-DOS 6, DR-DOS 7.03, PTS-DOS) when (re-)initializing
the serial devices is AL=A3h (2400 bps, no parity, 1 stop bit, 8 data bits).
SeeAlso
: AH=04h"SERIAL",AH=04h"MultiDOS",AH=05h"SERIAL",AH=57h
SeeAlso
: AX=8000h"ARTICOM",AH=81h"COMM-
DRV",AH=82h"COURIERS",AH=8Ch
SeeAlso
: MEM 0040h:0000h,PORT 03F8h"Serial"
Bitfields for serial port parameters:
Bit(s) Description (Table 00300)
7-5 data rate (110,150,300,600,1200,2400,4800,9600 bps)
4-3 parity (00 or 10 = none, 01 = odd, 11 = even)
2 stop bits (set = 2, clear = 1)
1-0 data bits (00 = 5, 01 = 6, 10 = 7, 11 = 8)
SeeAlso
: #00302,#00307,#00308,#00309
INT 14 - SERIAL - WRITE CHARACTER TO PORT
AH = 01h
AL = character to write
DX = port number (00h-03h) (04h-43h for Digiboard XAPCM232.SYS)
Return
: AH bit 7 clear if successful
AH bit 7 set on error
AH bits 6-0 = port status (see #00304)
Notes
: various network and serial-port drivers support the standard BIOS
functions with interrupt-driven I/O instead of the BIOS's polled I/O the 1993/04/08
Compaq system ROM uses only the low two bits of DX
SeeAlso
: AH=02h,AH=0Bh"FOSSIL",AX=8000h"ARTICOM",AH=89h,MEM
0040h:007Ch
INT 14 - SERIAL - READ CHARACTER FROM PORT
AH = 02h
AL = 00h (ArtiCom)
DX = port number (00h-03h (04h-43h for Digiboard XAPCM232.SYS))
Return
: AH = line status (see #00304)
AL = received character if AH bit 7 clear
Notes
: will timeout if DSR is not asserted, even if function 03h returns data
ready various network and serial-port drivers support the standard BIOS functions
with interrupt-driven I/O instead of the BIOS's polled I/O the 1993/04/08 Compaq
system ROM uses only the low two bits of DX
SeeAlso
: AH=01h,AH=02h"FOSSIL",AH=84h,AH=FCh
INT 14 - SERIAL - GET PORT STATUS
AH = 03h
AL = 00h (ArtiCom)
DX = port number (00h-03h) (04h-43h for Digiboard XAPCM232.SYS)
Return
: AH = line status (see #00304)
AL = modem status (see #00305)
AX = 9E00h if disconnected (ArtiCom)
Note
: the 1993/04/08 Compaq system ROM uses only the low two bits of
DX
SeeAlso
:
AH=00h,AH=07h"MultiDOS",AX=8000h"ARTICOM",AH=81h"COURIERS",AX=FD
02h
Bitfields for serial line status:
Bit(s) Description (Table 00304)
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
Note
: for COMM-DRV, if bit 7 is set, an error occurred, and may be retrieved
through a separate call (see AX=8000h"COMM-DRV")
Bitfields for modem status:
Bit(s) Description (Table 00305)
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
INT 14 - SERIAL - EXTENDED INITIALIZE (CONVERTIBLE,PS)
AH = 04h
AL = break status
00h if break
01h if no break
BH = parity (see #00307)
BL = number of stop bits
00h one stop bit
01h two stop bits (1.5 if 5 bit word length)
CH = word length (see #00308)
CL = bps rate (see #00309)
DX = port number
Return
: AX = port status code (see #00304,#00305)
SeeAlso
: AH=00h,AH=1Eh,AX=8000h"ARTICOM"
(Table 00307)
Values for serial port parity:
00h no parity
01h odd parity
02h even parity
03h stick parity odd
04h stick parity even
SeeAlso
: #00300,#00308,#00309,#00310
(Table 00308)
Values for serial port word length:
00h 5 bits
01h 6 bits
02h 7 bits
03h 8 bits
SeeAlso
: #00300,#00307,#00309,#00345
(Table 00309)
Values for serial port bps rate:
00h 110 (19200 if ComShare installed)
01h 150 (38400 if ComShare installed)
02h 300
03h 600 (14400 if ComShare installed)
04h 1200
05h 2400
06h 4800 (28800 if ComShare installed)
07h 9600
08h 19200
---ComShare---
09h 38400
0Ah 57600
0Bh 115200
SeeAlso
:
#00300,#00307,#00309,#00346,#00353,AH=36h,#00364,#00606,#02923
INT 14 - SERIAL - EXTENDED COMMUNICATION PORT CONTROL
(CONVERTIBLE,PS)
AH = 05h
AL = function
00h read modem control register
Return: BL = modem control register (see #00334)
AH = status