IBM 5170 Technical Reference page 258

; ------ I NCREMENT A BUFFER PO INTER
007F .4
PROC NEAR
007F
4'
INC BX MOVE TO NEXT WORD IN LI ST
0080
INC
BX
0081
' "
3 B lE 0082 R
eMP BX, BU FFER_END AT END OF BUFFER?
0085 75 04
JNE K5 ; NO, CaNT I NUE
0087 8B 1 E 0080 R
MOV BX,BUFFER_START ; YES, RESET TO BUFFER BEGINNING
008B
K5:
008B
C,
RET
008C
K4 ENDP
;------ KEYBOARD INTERRUPT ROUTINE
008C
KB_INT_l PROC FAR
008C FB
ST I ; ENABLE INTERRUPTS
0080 55 PUSH
BP
008E
50 PUSH
AX
008F PUSH
5'
BX
0090 51 PUSH
ex
0091
52 PUSH
OX
0092
56
PUSH 51
0093 57 PUSH
01
0094 1E PUSH
OS
0095 06
PUSH
ES
0096
Fe
CLD FORWARD DIRECT ION
0097 E8 0000 E CALL
DDS SET UP ADDRESSING
009A BO AD
MOV AL, 01 S_KBD o I SABLE THE KEYBOARD
009C E8 0498 R CALL
SH! P_IT
EXECUTE
01
SABLE
;------- WAIT FOR COMMAND TO ACCEPTED
009F FA
CLI
; DISABLE INTERRUPTS
DOAD 2B C9
SUB
eX,ex
00A2
KB_INT_Dl :
00A2 E4 64
IN
AL, STATUS_PORT ;
00A4 A8 02 TEST AL,INPT_BUF_FULL
00A6 EO FA
lOOPNZ KB_INT_Ol WAIT FOR COMMAND TO BE ACCEPTED
00A8 E4 60
IN READ I N THE CHARACTER
OOAA FB
STI
ENABLE INTERRUPTS AGA I N
;--------CHECK FOR A RESEND COMMAND TO KEYBOARD
OOAB
3C FE
eMP AL, KB~RESEND ; I S THE
J
NPUT A RESEND
OOAD 74 00
JE KB_I NT_4 ; GO I F RES END
; ------- CHECK FOR RESPONSE TO A COMMAND TO KEYBOARD
OOAF 3C FA eMP Al, KB_ACK ; I S THE I NPUT AN ACKNOWLEDGE
OOBl 75 12
JNZ
KB_INT_2 ;GOIFNOT
;------- A COMMAND TO THE KEYBOARD WAS ISSUED
00B3 FA CLI ; DISABLE INTERRUPTS
00B4 80 DE 0097 R 10 OR KBJLAG_2,KB_FA; INDICATE ACK RECEIVED
00B9 E9 01E2 R JMP K26 ; RETURN I f NOT (TH I SACK RETURNED FOR DATA)
; -------- RESENO THE LAST BYTE
OOBC KB INT 4;
OOBC FA DISABLE INTERRUPTS
- - Cli
ODBD 60 DE 0097 R 20
OR
KBJLAG_2,KB_FE; INDICATE RESEND RECEIVED
00C2 E9 01 E2 R JMP K26 ; RETURN IF NOT (THIS ACK RETURNED fOR DATA)
00C5 KB_I NT_2:
;--------UPDATE MODE INDICATORS IF CHANGE IN STATE
00C5 50 PUSH
AX
SAVE DATA IN
00C6 E6 046A R
CALL GO GET MOD[ INDICATOR DATA BYTE
00C9 6A lE 0097 R
MOV
=t~~B~~EAG_2
GET PREV 10US BITS
OOCD 32 08 XOR BL,AL SEE I F ANY OJ FFERENT
OOCF
60 £3 07 AND Bl,07H
ISOLATE INDICATOR BITS
0002 711 03
JZ
UPO
I F NO CHANGE BYPASS UPDATE
0004 E8 0439 R CALL SND~LEO GO TURN ON MODE INDICATORS
0007 5B UPO:
POP AX
RESTORE DATA IN
0008 8A EO MOV AH,AL SAVE SCAN CODE IN AH ALSO
; ------ TEST FOR OVERRUN SCAN CODE FROM KEYBOARD
DODA 3C FF
eMP
AL,OFFH IS TH [S
AN
OVERRUN CHAR
OODC 75 03
JNZ
NO, TEST FOR SHI
FT
KEY
DODE E9 0306 R JMP K62 BUFFERJULl_BEEP
"6
; ------ TEST FOR SH I FT KEYS
OOEl K16: TEST SHIFT
OOEl 24 7F AND AL,07FH
TURN-OFF THE BREAK BIT
00E3 DE
PUSH
CS
00E4
07 POP ES
ESTABLISH ADDRESS OF SHIFT TABLE
;-----~- TEST FOR SYSTEM kEY
00E5 3C 54 CMP AL, SYS_KEY
I SIT THE SYSTEM KEY?
00E7 75 3D
JNZ
K16A CONT I NUE I F NOT
00E9
F6 C4 60 TEST AH,080H CHECK If TH I S A BREAK CODE
DOEC 75 21
JNZ
K16C DONT TOUCH SYSTEM INDICATOR I F TRUE
OOEE F6 06 0016 R 04
TEST KB FLAG_l,SYS_SHIFT ; SEE IF IN SYSTEM KEY HELD DOWN
00F3 75 17 JNZ
K16B ; I F YES, DONT PROCESS SYSTEM INDlCATOR
00F5
80 0018 OR KB_FLAG_ 1, SYS_SH 1FT; I NO I CATE SYSTEM KEY DEPRESSED
OOFA BO 20 MOV
AL,EOt ; END OF INTERRUPT COMMAND
OOFC E6 20
OUT
020H,AL ; SEND COMMMD TO INTERRUPT CONTROL PORT
; INTERRUPT-RETURN-NO-EOI
OOFE BO AE MOV AL, ENA_KBD
; I NSURE KEYBOARD I S ENABLED
0100 E8 0498 R
CALL
SHIP IT
; EXECUTE ENABLE
0103 B6 8500 MOV AX,08500H FUNCTION VALUE FOR MAKE OF SYSTEM KEY
0106
Fa
ST I
MAKE SURE I NTERRUPTS ENABLED
0107 CO 15 I NT 15H USER I NTERRU PT
0109 E9 01EC R JMP K27A END PROCESS I NG
OlOC
E9 01E2 R
K16B: JMP
'26
IGNORE SYSTEM KEY
DE
R 0"
OlOF 80 26 0018 R Fa K16C: AND
KB_FLAG_ 1, NOT SYS_SH 1FT; TURN OFF SH I FT KEY HELD DOWN
0114 BO 20
MOV
AL, EO I ; END OF I NTERRUPT COMMAND
0116 E6 20
OUT
02QH,AL ; SEND COMMAND TO INTERRUPT CONTROL PORT
; 'NTERRUPT-RETURN-NO-EO I
0118 BO AE MOV AL, ENA_KBD
; I NSURE KEYBOARD t S ENABLED
OllA E8 0498 R CALL SHI P IT ; EXECUTE ENABLE
0110 B8 8501 MOV AX,08501H
FUNCT I ON VALUE FOR BREAK OF SYSTEM KEY
0120 FB
sn
MAKE SURE INTERRUPTS ENABLED
0121 CD 15 INT 15H USER INTERRUPT
5-116 Keyboard