BIOS
/ BIOS
.
, (
, , ) BIOS RS-232C, 14h.
14h . DX. DX
COM1, ,
COM2.
AL , 8-7. 3- , - 2-
, - -
2- . 8-2
. , COM DOS 3.3
19200 , , ROM-BIOS 9600 .
, 8-2,
,
.
- a.
-
000 110 00 0 1 10 7
b.
001 150 10 1 2 11 8
010 300 01c.
011 600 11d.
100 1200
101 2400
110 9600
111
.8-7. ,
, 14h BIOS
a.- ; b. - ; c. - ; d. -
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8-2
14h
- 110 0
150 1
300 2
600 3
1200 4
2400 5
4800 6
9600 7
0 2
1
3
1 0
2 1
7 2
8 3
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. ,
, ,
:
pckd_commparams = (baudrate << 5) | (parity <<3) |
(stopbits << 2) | (wordlength);
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. baudrate, parity, stopbits
wordlength
8-2.
, BIOS 14h. int86 Microsoft
:
#include
#define BIOS_RS232 0x14
/* BIOS */
static union REGS xr, yr;
.
.
.
xr.h.ah = 0; /* BIOS RS-232 */
xr.h.al = pckd_commparams; /* */
xr.x.dx = port_number; /* 0 COM1, 1 COM2 */
int86(BIOS_RS232, &xr, &yr); /* */
.
.
.
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Microsoft C 5.0
BIOS: _bios_serialcomm
BIOS 14h. ,
8- , 1 ,
300 ,
,
. service_code port_number 0
(COM1) 1 (COM2). data .
Microsoft C 5.0
Run-time Library Reference.
_bios_serialcom(_COM_INIT, COM1, (_COM_CHR8 | _COM_STOP1 |
_COM_NOPARITY | _COM_300) );
_bios_serialcom
status = _bios_serialcomm(service_code, port_number, data);
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