IBM 5150 - 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