Octagon PC-500, Руководство пользователя

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18-5
PC-500 user’s manual Serial EEPROM and CMOS RAM
Calling registers: AH fch
AL 04h
DX ffffh
Return registers: Carry flag cleared if successful
AX
Size of the serial EEPROM (in words)
BX Size available to user (in words)
Carry flag set if error
AL
Error code
Error code Meaning
ffh Unknown error
01h Function not implemented
02h Defective serial EEPROM
03h Illegal access
Comments: This function returns the size (in words) of the serial
EEPROM. Since the user cannot access all of the
serial EEPROM, this function determines how much
space is available to the user. This avoids the user
from accessing unavailable addresses.
Programming example:
unsigned int seeUserSize;
/* Inline assembly code for Borland C++ 3.1 */
asm {
mov ax,0fc04h
mov dx,0ffffh
int 17h
mov seeUserSize,bx
}
≡
CMOS RAM
Read extended CMOS RAM
Function: fbh
Subfunction: 06h
Purpose: To read a single byte from the extended CMOS RAM.
Calling registers: AH fbh
AL 06h
BL CMOS index (0-127)
DX ffffh
Return registers: Carry flag cleared if successful
BH
CMOS data
Carry flag set if error
AL
Error code