Octagon PC-500, Руководство пользователя

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11-8
EZ I/O PC-500 user’s manual
Return registers: Carry flag cleared if successful
Carry flag set if error
AL
Error code
Comments: This function is used to initialize the EZ I/O before normal
use.
Programming example:
/* Inline assembly code for Borland C++ 3.1 */
asm {
mov ax,0ef01h
mov di,00ffh /*port A: no change */
mov bx,8000h /*port B: bit 7=0, other bits unchanged*/
mov cx,0202h /*port C: bit 1=1, other bits unchanged*
mov dx,0ffffh
int 17h
}
Read EZ I/O
Function: efh
Subfunction: 02h
Purpose: To read from an EZ I/O port.
Calling registers:
AH efh
AL 01h
xxxxxxxx Data for port C
DX ffffh
Return registers: Carry flag cleared if successful
AL
Port A data
AH Port B data
BL Port C data
Carry flag set if error
AL
Error code
Comments: This function is used to read from the EZ I/O before nor-
mal use.
Programming example:
/* Inline assembly code for Borland C++ 3.1 */
unsigned char aData, bData, cData;
asm {
mov ax,0efoch
mov dx,0ffffh
int 17h
mov aData,al
mov bData,ah
mov cData,bl
}