IBM 5150 Technical Reference page 201

LOC OBJ
LINE SOURCE
FA34 74FA
5712 JZ
, LOOP TILi.. HIGH
"2'
FA36
5713
W30:
FA36 E462
5714
IH
AL,PORT.C I NOW WAIT TILL TINER'S OUTPUT IS LOW
FA38 242:0 57lS AND
AL.020H
FA3A 75FA
5716 JHZ W30
5717
I
RELOAD TIttER WInt PERIOD
5718
~
FOR NEXT DATA BIT
'A3e 58 5719
pop
AX ~ RESTORE PERIOD COUNT
FA30
5720 1431:
; SET TIMER
fA3D E64::!
5721 OUT
042H. AL
~
SET LOW BYTE OF TIttER 2
FA3F 6AC4
5722
HOV
Al. AH
FA41 E642
572:3
OUT
042H. AL I SET HIGH BYTE OF TIttER 2
FA43 C3 5724 RET
5725
WRITE.BIT ENDP
5726 ; -- --------------------- _________
~
- _____________ _
5727 UPDATE CRC REGISTER WITH NEXT DATA BIT
5728 CRC IS USED TO DETECT READ ERRORS
5729 ASSUHES DATA BIT IS IN CARRY
5730
5731 REG AX IS MODIFIED
5732 FLAGS ARE HODIFIED
~------------------------------------------------
,.44 5733
5734 CRC_GEN PROC NEAR
FA44 A16900
5735
HOV
5736
I THE FOLLOWING INST\JCTlONS
5737
; WILL SET ntE OVERFLOW FlAG
5738
; IF CARRY AtIJ HS BIT OF CRC
5739
I
ARE ~QUAL
FA47 0108
5740 RCR
AX'!
FA49 DIDO
5741
RCl
AX')
FA48 F8
5742
ClC
I
CLEAR CARRY
FA4C 7104 5743 JNO
W3.
; SKIP IF NO OVERFLOW
5744 ~
IF DATA BIT XORED WITH
5745
I
CRC REG BIT 15 IS ONE
FA4E 351008 5746
XOR AX,0810H
I
THEN XOR CRC REG WITH 0801H
FA51 F9
5747
STC
I
SET CARRY
FA52 5748 1432:
FA52: DIDO
5749 RCl AX,)
I
ROTATE CARRY (DATA BIll
5750 ; INTO CRC REG
FA54 "36900 5751
MOV
CRC.REG,AX I UPDATE CRC.REG
FA57 C3 5752 RET
I
FINISHED
5753 CRC.GEN ENDP
5754
FA58 5755
BEGIN_OP PROC HEAR
~
START TAPE AHO DE LAY
FA58 E82:6FE 57. . CAll
HOTOR.ON
; TURN ON HOTOR
FASB B342 5757
HOV
Bl,42H ;DELAY FOR TAPE DRIVE
5758 ; TO GET UP TO SPEED (l/2 SEC
I
FASO 5759 1433:
FASO 890007 5760
HOV
CX.700H
IIht-lER looP= APPROX. 10 ttILLISEC
FA60 ElFE
5761 1434: lOOP W34
FA62: FEce 5762 DEC
Bl
FA64 75F7
5763
JNZ W33
FA66 C3
5764
RET
5765 BEGIN..OP EIIIP
5766
FA67 2:0323031 5767 EI DB • 201'
,13,10
FA68 00
FA6C 0...
5768
5769
1---------------------------------------------------------------------- ­
5770 CHARACTER GENERATOR GRAPHICS FOR 320X200 AND 640X200 GRAPHICS
5771
1---------------------------------------------------------------------- ­
FA6E 5772 ORS OFA6EH
FA6E 5773 CRT_CHAR.GEN LABEl BYTE
FA6E 0000000000000000 5774 DB OOOH,OOOH,OOOH,OOOH,OOOH,OOOH,OOOH,OOOH
I
0_00
FA76 7E8USS1BD99817E
5775 DB 07EH,081H,OA5H,081H,OBOH,099H,OSIH,07EH
I
0.01
FA 7E 7EFFDBFFC3E7FF7E
5776
DB
07EH,OFFH,ODBH,OFFH.OClH.OE7H,OFFH.07EH I 0.02
FA86 6CFEFEFE7C3810ao
5777
DB
06CH.OFEH,OFEH,OFEH,07CH,038H,OlOH.OOOH I 0.03
FASE l0387CFE7C381000
5778
08 010H,038H,07CH,OFEH,07CH,038H.OIOH,OOOH 10.04
FA96 387C38FEFE7C387C
5779 08 038H.07CH,03SH,OFEH,OFEH,07CH,038H,07CH ; 0.05
FA9E lOl0387CFE7C387C 5780
D.
010H.OIOH,038H,07CH,OFEH,07CH,038H,07CH I D.06
FAA6 0000183C3C180000 5781 08 OOOH,000H.018H,03CH,03CH.0ISH,OOOH,OOOH I 0.07
FAAE FFFFE7C3C3E7FFFF 5782 DB OFFH.OFFH,OE7H,OC3H.OC3H.OE7H,OFFH,OFFH
j
0.08
FAS6 003C664242:663COO 5783 DB 000H,03CH,066H,042H,042H,066H,03CH.OOOH ; 0_09
FASE FFC399BDBD99C3FF 5784
DB OFFH,OC3H,099H,OBDH,OBDH.099H,OC3H,OFFH ; 0.0'"
FAC6 OF070F7DCCCCCC78 5785
DB
OOFH,007H,00FH,070H,OCCH,OCCH,OCCH,07SH I D.OB
FACE 3C0666663C187E18 5786
DB 03CH,066H,066H,066H,03CH,018H,07EH,OI8H. I D.OC
5-108 System BIOS