IBM 5170 Technical Reference page 268

0044 BF 0000 E
MOV
OI,OFFSET A1 BASE OF TABLE
0047 03 FA
ADD OI,OX
PUT I NTO I NDEX REG I STER
0049 8B 94 0000 R MOV OX, RS232_BASE[ S I 1
POINT TO HIGH ORDER OF DIVISOR
0040
42 INC
OX .
004E 2E: 8A 45 01
MOV AL,CS:[Olj+l
GET HIGH ORDER OF DIVISOR
0052 EE OUT DX,AL SET MS OF DIV TO 0
0053 4A DEC
ox
0054 EB 00 JMP SHORT $+2 10 DELAY
0056 2E: 8A 05 MOV AL,CS:[DIJ
GET LOW ORDER OF DIVI SOR
0059
EE
OUT DX,AL SET LOW OF DIVISOR
005A 83 C2 03
ADD
DX,3
0050 8A C4
MOV AL,AII
GET PARMS BACK
005F 24 1F
AND
AL,Ol FH STR I P OFF THE BAUD BITS
0061 EE OUT DX,Al LINE CONTROL TO 8 BITS
0062
4A DEC
ox
0063 4A DEC
ox
0064 EB 00 JMP
SHORT $+2 10 DELAY
0066 BO 00
MOV
AL,a
0068
EE
OuT aX,AL
I NTERRUPT ENABLES ALL OFF
0069 EB 4B
JMP
SHORT AlB COM_STATUS
;------ SEND CHARACTER IN (AL) OVER COMMO LINE
006B AS:
006B
50 PUSH
AX
SAVE CHAR TO SEND
006C 83 C2 04 ADD DX,4 MODEM CONTROL REGISTER
006F
BO 03
MOV
AL,3 OTR ANO RTS
0071
0072
EE
42
OUT
INC
OX,AL
ox
DATA TERMINAL READY, REQUEST TO SEND
MODEM STATUS REGISTER
0073
42
INC
ox
0074
B7 30
MOV
BH,30H
DATA SET READY
&
CLEAR TO SEND
0076 EB OOC5 R GALL WAI T_FOR_STATUS ARE BOTH TRUE
0079 74 08 JE A9
YES, READY TO TRANSM I T CHAR
007B
A7:
007B 59
POP
cx
007C SA Cl MOV AL,Cl
RELOAD DATA BYTE
007E
A8:
007E 80 CC 80 OR AH,80H INDICATE TIME OUT
0081 EB A8
JMP A3
RETURN
0083 A9:
CLEAR_
TO_SE~D
0083 4A
DEC OX
LINE STATUS REGISTER
0084
A10: WAIT SEND
0084 B7 20 MOV BH,20H IS TRANSM I TTER READY
0086 E8 00C5 R
CALL
WA
I T
_FOR_STATUS
TEST FOR TRANSMITTER READU
0089 75 Fa JNl A7 RETURN WITH TIME OUT SET
008B All: OUT CHAR
008B 83 EA 05
SUB
DX,S DATA PORT
008E 59 POP CX RECOVER
IN CX TEMPORARILY
008F 8A C1 MOV AL,CL MOVE CHAR TO AL FOR OUT, STATUS IN AH
0091
EE
OUT DX,AL
OUTPUT CHARACTER
0092 EB 97
JMP A3
RETURN
;------ RECEIVE CHARACTER FROM COMMO LINE
0094 Al2:
0094
83 C2 04
ADD DX,4
MODEM CONTROL REG
r
STER
0097
BO 01
MOV AL,l
DATA TERMINAL
READY
0099
009A
EE
42
OUT
INC
DX,AL
ox
MODEM STATUS REG I STER
009B
42
INC
ox
009C A13:
WAIT_DSR
009C
B7 20
MOV
BH,20H DATA SET READY
009E E8 00C5 R CALL WAIT
-
FOR_STATUS TEST FOR OSR
OOAl 75 DB JNL
A8
RFTURN WITH ERROR
00A3 A15: WAIT DSR END
00A3 4A DEC OX
LlNCSTATUS REGISTER
OOA4 A16: WAIT
RECV
OOA4 B7 01 MOV
BH,l
RECEIVE BUfFER FULL
00A6
E8 OOC5 R
CALL WAIT_ FOR_STATUS
TEST fOR REC. BUfF, FULL
OOA9
75 03 JNZ A8
SET T I ME OUT ERROR
OOAB
DOAB
OOAE
0082
80 Eli 1£
8B 94 0000 R
EC
Al7:
AND
MOV
IN
AH,00011'10B
DX,RS232_BASE[ SI
J
AL,DX
~~hG~~~
ERROR CONDITIONS ON RECV CHAR
DATA PORT
GET CHARACTER FROM LINE
00B3 E9 0028 R
JMP A3
RETURN
;-~---- COMMO PORT STATUS ROUTINE
00B6 A18:
00B6
88
94 0000 R MOV OX,RS232 BASE[SI]
OOBA 83 C2 05 ADD
OX,5 - CONTROL PORT
OOBO
EC
IN AL, OX GET LINE CONTROL STATUS
OOBE
8A EO
MOV
AH,AL PUT IN AH FOR RETURN
OOCO
42
INC Ox
POINT TO MODEM STATUS REGISTER
OOCl EC IN
AL,DX
GET MODEM CONTROL STATUS
OOC2
E9 002B R
JMP A3
RETURN
;
-------
---
---- ------ ----------------
----­
; ENTRY:
~~!~Tf~~sS~Nn)R~gT~g6K
FOR,
; EX IT:
g~~~D~~AGO~N S~A~~~T~~G
FOUND
ZERO FLAG OFF'" TIMEOUT,
AH=LAST STATUS READ
00C5
~~ 7~: ;;~R:STAT~S-;R;;;;--
--
N~A~--
------------ ­
OOC5 8A 90 007C R
MOV BL,RS232_TlM_OUT[DIJ ; LOAD OUTER LOOP COUNT
;------ADJUST DUTTER LOOP COUNT
00C9 55
PUSH
BP SAVE BP -----­
OOCA 53
PUSH
BX SAVE BX -----­
OOCB 50 POP BP USE BP FOR OUTTER LOOP COUNT
OOCC 81 E5 DOFF AND BP,OOFFH
STRIP HIGH BITS
0000 01 05 ReL BP,l
MUll DUTTER BY 4
0002 01 05 ReL BP,l
0004 2B C9
WFSO: SUB
ex,cx
00D6 EC WFS1: IN AL,DX
;GET
STATUS
0007 8A EO
MOV
AH,AL ; MOVE TO AH
0009 22 C7 AND AL,BH ; ISOLATE BITS TO TEST
OOOB 3A C7 CMP AL,BH
; EXACTLY
=
TO MASK
0000 74 07
JE
WFS_END ; RETURN WITH ZERO FLAG ON
OOOF E2 F5 LOOP WFSl
;TRY AGAIN
00(1 40 DEC BP
;
---- ­
00E2 75 FO
JNZ WFSO
00E4 OA
rF
OR BH, BH
; SET ZERO FLAG OFF
00E6
WFS_ENO:
00E6 50 POP RESTORE BP ---- ­
Don
C3
RET
00E8
WAIT FOR STATUS ENOP
00E8
RS232~IO=1
ENOP
00E8
CODE ENDS
5-126 RS232