IBM 5150 Hardware Reference Manual page 213

LaC OSJ
LINE SOURCE
E6EC eSOAOE
E6EF COlO
£6fl Cl
E6F2
E6F2: FB
E6F3 884000
E6F6 8£08
E6Fe All000
E6F8 A801
E6FD 7423
E6FF 890400
E702
noz
51
£703 8400
E705 CDll
n07 7214
£109 8402
£10& B80000
E70E 8fC3
E7l0 BB007C
E713 BAOOOO
E7l6 8901QO
E7l9 B001
E7lB CDl3
E7lD 59
E7lE 7304
E720 £2£0
£722:
E72:O! C018
E7Z4
e724 EAOO7COOOO
1351 MOV AX,OEOAH ; LINE FEED CHARS
1352:
ItH
10H
1353
RET
1354 P _HSG EHOP
1355 ;--- INT 19 ----------------------------­
1356 I BOOT STRAP LOADER
1357 IF A 5 1/4" DISKETTE DRIVE IS AVAIlABLE
1358 ON THE SYSTEM. TRACK 0, SECTOR 1 IS READ INTO THE
1359 BOOT LOCATION (SEG~IENT O. OFFSET 7COO}
1360 Aim CONTROL IS TRANSFERRED THERE.
1361
1362 IF TIiERE IS NO DISKETTE DRIVE. OR IF THERE IS
1363 IS A HAROWARE ERROR CONTROL IS TRANSFERREO
1364
TO THE CASSETTE BASIC
E~Y
POINT.
1365
1366 I IPl ASSUMPTIONS
1367 8255 PORT bOH El:lT 0
1368
=
1 IF IPL FROH DISKETTE
1369 ; ------------------------------.--------­
1370
ASSUME CS:CDDE.DS:DATA
1371
BOOT.STRAP PROC NEAR
1372
1373 STI 1 ENABLE INTERRUPTS
1374 HOV
AX,DATA ; ESTABLISH ADDRESSING
1375 HOV OS,AX
1376
HOV AX. EQUIP
JUG
; GET THE EQUIPMENT SWITCKE'
1377
TEST ALd J ISOLATE IPL SENSE SWITCH
1378 JZ
H3 ;, GO TO CASSETTE BASIC ENTRY POINT
1379
1380 ;------ MUST LOAD SYSTEM FROM DISKETTE -­
ex
HAS RETRY COUHT
1381
1382
NOV
CX.4 ; SET RETRY COUNT
1383
HI:
J IPL.SYSTEH
1384 PUSH
ex
; SAVE RETRY COl.mT
1385
HOV
AH,O
; RESET THE DISKETTE SYSTEM
1386
INT
13ft
j
DISKETTE.IO
1387 JC HZ I IF ERROR. TRY AGAIN
1388 HOV AH,2 ; READ IN THE SINGLE SECTOR
1389 MOV BX.O
; TO THE BOOT LOCATION
1390
MOV ES,BX
1391 HOV eX,oFFSET BOOT.LOCN
139Z HOV
OX,O I
DRIVE
0,
HEAD 0
1393
MOV CX.! ; SECTOR
I,
TRACK
0
1394 NOV AL,I ; READ ONE SECTOR
n95 INT
IlH
i
DISKETTE.IO
1396 POP
ex
j
RECOVER RETRY COUNT
1397 JNe H4 ; CF SET BY UNSUCCESSFUL READ
1398 LOOP HI
j
DO IT FOR RETRY TIMES
1399
1400
j------
UNABLE TO IPL FROM THE DISKETTE
1401
1402
H3:
I CASSETTE_JUMP:
1403 INT 18H ; USE INTERRUPT VECTOR TO GET TO BASIC
1404
1405 1------ IPL WAS SUCCESSFUL
1406
1407
H4:
1406
1409
1410
; -----INT 14----­ ---------------------------­
1411 ;RS232_IO
1412 THIS ROUTINE PROVIDES BYTE STREAM I/O TO THE: COf1MUNICATIOHS
1413
PORT ACCORDING TO THE: PARAMETERS:
1414
(AH )=0 INITIALIZE TItE COMMUNICATIONS PORT
1415
j
AL) HAS PARMS fOR INITIALIZATION
1416
1417
7 • 4 I
1416
----­ BAUD RATE -­
-PARITY-­ STOPBIT --WORD
1419
1420
000 - 110
xo -
NONE
o ­
1
10 - 7
1421
001 - 150
01 - COD
1 - Z 11 - 8
1422 010 - 300
11 - EVEN
1423
011 -
600
1424
100 - 1200
1425
101 - 24QO
1426
110 - 4600
1427
III -
9600
lENGTH-­
BITS
BITS
A-20