IBM AT 5170 Technical Reference page 308

- -
IBM Personal Computer MACRO Assembler Ver5,on 2.00
KYBO ----- 06/10185 KEYBOARD BIOS
800
;
-----
TRANSLATE THE CHARACTER
8"
'"
802 0486
K5b: TRANSLATE-CHAR
803 0486 FE CB
DEC AL CONVERT ORIGIN
804 0488 2E
=
01
XLAT CS:K
I I
CONVERT THE SCAN CODE TO ASC I I
80S
806
;-----
PUT CHARACTER I NTO BUFFER
801
808 048A
K571 BUFFER-F I LL
809 048A 3C FF
eMP AL,-1
Is
THIS AN IGNORE CHAR
810 048C 14 IF
eE K59 YES. DO NOTH I NG WITH IT
81 I 04BE 80 FC FF CMP AH,-I LOOK FOR -I PSEUDO SCAN
812 0491 14 IA
eE K59 NEAR_l NTERRUPT _RETURN
813
81' HANDLE THE CAPS LOCK PROBLEM
815
8 I 6 0493
K58 : BUFFER-F I LL -NOTES T
8110493F6060017R40
TEST
a.KB FLAG,CAPS STATE ARE WE IN CAPS LOCK STATE
818 0498 14 20
ez
K6'- -
SK I P IF NOT
8"
820
IN CAPS LOCK STATE
821
822 049A F6 06 0011 R 03
TEST .KB FLAG,LEFT SHIFT+RIGHT SHIFT; TEST FOR SHIFT STATE
823 049F 14 OF .JZ K60- ;-IF NOT SHIFT, CONVERT LOWER TO UPPER
82.
825
CONVERT ANY UPPER CASE TO LOWER CASE
826
827 04AI 3C 41 CMP
AL, 'A' FIND OUT
IF ALPHABET 1 C
828 04A3 12 15
eB K61 NOT CAPS STATE
829 04A5 3C 5A
CMP AL, 'Z'
830 04A1 1711
JA K61 NOT CAPS STATE
B31 04A9 04 20
ADD AL,'
01'-
'A' CONVERT TO LOwER CASE
832 04AB EB 00 JMP SHORT K61
NOT_CAPS
-
STATE
833
834 04AD K59:
NEAR-I NTERRUPT-RETURN
835 04AD E9 02EE R eMP
K26 INTERRUPT RETURN
836
-
831
; ----- CONVERT ANY LOWER CASE TO UPPER CASE
838
B39 04BO K60: LOWER-TO-UPPER
B40 04BO 61
CMP AL,' a' FIND OUT IF ALPHABETIC
841 04B2 12 06
JB K61 NOT_CAPS_STATE
842 04B4 3C 1 A CMP
AL,'
2 '
B43 04B6 11 02
JA K61
NOT CAPS STATE
B44 04BB 2C 20
SUB AL,' a' - 'A' CONVERT TO UPPER CASE
8.5
846 04BA Kbl,
NOT-CAPS-STATE
847 04BA BB IE OOIC R
~OV BX ••BUFFER_TAl L GET THE END PO I NTER TO THE 8UFFER
848 04BE BB F3
MOV SI,BX SAVE THE VALUE
B49 04CO E8 001F R CALL
K'
ADVANCE THE TAl L
B50 04C33B IE OOIA R CMP
BX, .BUFFER_HEAD
HAS THE BUFFER WRAPPED AROUND
B51 04C1 14 22
eE K62 BUFFER FULL BEEP
852 04C9 89 04
MOV (si)
,AX
STORE THE VALUE
B53
04CB 69 IE OOIC
R
MOV
.BUFFER _TAIL,8X MOVE THE PO I NTER UP
854 04CF FA CL I TURN OFF INTERRUPTS
855 0400 BO 20 MOV
AL,EOI END OF I NTERRUPT COMMAND
856 0402 E6 20 OUT INTAOO,AL SEND COMMAND TO INTERRUPT CONTROL PORT
851 0404 BO AE MOV
AL,ENA_KBD I NSURE KEYBOARD I S ENABLED
858 0406 EB 0595 R CALL
SHIP IT EXECUTE ENABLE
859 0409 86 9102 MOV
AX,09102H MOVE I N POST CODE
&
TYPE
860 04DC CD 15 I NT ISH PERFORM OTHER FUNCT! ON
861 04DE E9 02F8 R eMP
K27A I NTERRUPT ~RETURN
862
863
86.
TRANSLATE SCAN FOR PSEUDO SCAN CODES
865
666 04EI
TRANSLATE-SCAN
861 04EI 2C 3B SUB
CONVERT OR I GIN TO FUNCT I ON KEYS
666 04E3 Kb4: TRANSLATE- SCAN-ORGD
869 04E3 2E: 01
XLAT CS:K9 CTL TABLE SCAN
870 04E5 8A EO
MOV
AH,AL
PUT VALUE INTO AH
871 04E1 BO 00
MOV AL,O ZERO ASC
J
I CODE
872 04E9 EB 9F
JMP K51
PUT I T I NTO THE BUFFER
813
814 04EB
KB_INT_I ENDP
815
816 04EB
K62:
811 04EB BO 20
MOV
AL,EOI ENABLE I NTERRUPT CONTROLLER CH I P
818 04EO E6 20
OUT INTAOO ,AL
819 04EF B9 02A6
~OV CX,678 DIVISOR FOR 1760 HZ
880 04F2 B3 04
MOV BL,4 SHORT BEEP COUNT 11/16 + 1/64 DELAY)
881 04F4 E8 0000 E
CALL
BEEP GO TO COMMON BEEP HANDLER
882 04F1 E9 02F3 R
JMP K21
EXIT
883
88. 1- - - ----------­
885 SND_DATA
886
881
THIS ROUTINES HANDLES TRANSMISSION OF COMMAND AND DATA BYTES
888
TO THE KEYBOARD AND RECE I PT OF ACKNOWLEDGEMENTS. I T ALSO
88' HANDLES ANY RETR I ES IF REQU I RED
890
891
892
893 04FA SND DATA PROC NEAR
894 04FA 50
~
PUSH AX
SAVE REGISTERS
895 04FB 53
PUSH BX
896 04FC 51 PUSH CX
891 04FD 8A F8
BH,AL SAVE TRANSMITTED BYTE FOR RETRIES
898 04FF B3 03
BL,3 LOAD RETRY COUNT
899 0501
SDO:
900 050 I FA
CLI ; DISABLE INTERRUPTS
90 I 0502 80 26 0091 R CF
AND <PKB_FLAG_2,NOT lKB_FE+KB_FAI : CLEAR ACK AND RESEND FLAGS
902
903
WA I T FOR ANY PEND I NG COMMAND TO BE ACCEPTED
90.
')05 0501 28 C9
SUB
cX,ex MAXIMUM WAIT COUNT
906 0509 501 :
901 0509 E4 64
IN AL,STATUS PORT READ KEYBOARD PROCESSOR STATUS PORT
908 0508 A8 02
TEST AL, I NPT BUF FULL CHECK FOR ANY PEND I NG COMMAND
909 0500 EO FA LOOPNZ SO I - -
WA I T FOR COMMAND TO BE ACCEPTED
910
911 050F 8A C1
MOV AL,BH REESTABLISH BYTE TO TRANSMIT
912 0511 E6 60
OUT PORT_A,AL SEND BYTE
5-136
KYBD