IBM PC CONVERTIBLE Technical Reference page 101

0386
0386
0388
038A
038D
0390
0393
0396
0396
0397
0399
039B
039B
039C
039D
039E
039F
03AO
03Al
03A2
03A3
03A4
03A4
03A4
03A5
03A6
03AA
03AC
03BO
03BO
03B1
03B1
BO 20
E6 20
BB 0053
B9 0081
E8 0000 E
EB 06 90
FA
BO 20
E6 20
07
IF
5F
5E
5A
59
5B
58
CF
43
43
BUFFER IS FULL, SOUND THE BEEPER
K62 :
MOV AL, EO! END OF INTERRUPT COMMAND
OUT INTAOO,AL SEND CMD TO INT CONTROL PORT
MOV BX,083 NO. CYCLES FOR 83 MSEC TONE
MOV
CX,081H 1/2 CYCLE FOR 1KHZ TONE
CALL
KB_NOISE
JMP
KYBD9_RET
RETURN WITHOUT EOI
,
-
- -- - - -- - - - - -
--
- - -
-- -
- - - -
--
; ISSUE EOI & RETURN
-----
- -- - - - - -- - - - - -
--
-- - -
--
KYBD9_EXIT :
CLI TURN OFF INTERRUPTS
MOV AL,EOI ISSUE EOI
OUT INTAOO,AL
RETURN WITH EOI ALREADY ISSUED
KYBD9_RET:
POP
ES RESTORE REGS
POP
DS
POP
DI
POP SI
POP DX
POP CX
POP BX
POP
AX
IRET ; RETURN: I RPTS SET BACK AS WERE
KYBD_INT9 ENDP
; **********************************************************************
ROUTINE-NAME: PTR_INC
FUNCTION: INCREMENT THE KEYBOARD BUFFER POINTER AND WRAP THE BUFFER
I F NECESSARY.
ENTRY CONDITIONS: DS= DATA SEGMENT
BX= POINTER TO INCREMENT
EXIT CONDITIONS:
BX INCREMENTED BY 2 AND I F BUFFER_END EXCEECE
BX IS SET TO BUFFER_START.
REGISTERS MODIFIED: BX
; **********************************************************************
PTR_INC PROC NEAR
INC BX MOV E TO N EXT WORD IN LIST
INC BX
3B IE 0082 CMP BX, BUFFER-END
AT END OF BUFFER?
75 04 JNE
PTR_Ol
NO, CONTI NU E
8B IE 0080 MOV BX, BUFFER-START YES, RESET TO BUFFER BEGINNING
PTR_01 :
C3 RET
PTR-INC ENDP
ROM CODE ENDS
END
2-76 ROM BIOS