IBM 5150 - Page 233

LOC OBJ LINE SOURCE
2870 I ~- --- ----------- ----------------------------
ze71 ; DISK_IHT
zan THIS ROUTINE HANOlES THE DISKETTE INTERRUPT
2873 ;INPUT
2674 ; NONE
2875 ; OUTPUT
287-6 THE INTERRUPT FUG IS seT IS SEEK ... STATUS
za77 ; ------------ --------------------------------
EF57
2878
DISK.INT FAR
""DC
EFS7 FB
2879
STI ; RE ENABLE INTERRUPTS
EFsa IE
2:880
PUSH DS
EF59 50
Z8a1
PUSH AX
EFSA 884000
Z68<:: MOV AX. DATA
EFSD SED!
HOV DS.AX
' .. 3
EF5F 800E3EOO&O
2884
OR SEEK_STATUS,lNTJLAG
EFM B020 28SS HOV
AL.20H f END OF INTERRUPT MARKER
EF66 E620 2886 OUT
2.0H,AL ; INTERRUPT CONTROL PORT
£F66 58 288-7
POP
AX
EF69 IF
2S8e
pcp
OS
; RECOVER SYSTEM
EFU C:P'
IRET ; RETURN FROM INTERRUPT
, ...
2690
EUDP
2891 ; ---.------------ - ---------------------------
2892 I RESULTS
2.893
THIS ROUTIf~E WILL READ ANYTHING THAT THE NEC CONTROLLER
2894 HAS TO SAY FOLLOWING AN INTERRUPT.
2895 INPUT
289'6
UONE
2897 I OUTPUT
2898 CY :: 0 SUCCESSFUL TRANSFER
2899 cv = 1 fAILURE -- TINE OUT W WAITING fOR STATUS
2900 NEe_STATUS AREA HAS STATUS BYTE LOAnED INTO IT
2901 (AH) DESTROYED
2. 90 l ; --- ----- - ------------ ----- ------------- -----
EF6B 2903 RESULTS !'ROC HEAR
EF6B
FC %904 CLD
EF6C Bf4Z00
uos
I10V DI.OFFSET NEC_STATUS ; POINT-ER TO DATA AREA
EF6F 51 2906 PUSH ex
; SAVE COUt..rTER
EF70
52
2907 PUSH ox
EF71 53
2908
PUSH ax
EF7! 6307
2909
HOV Bt.7
MAX STATUS BYTES
2910
2911 ~------ WAn FOR REQUEST FOR MASTER
291l
EFlIt 2913
J38:
i INPUT_LOOP
EF74
33C9
2914
XOR CX.cx
;
COUNTER
EF76 BAF403 2'HS MOV DX,Q3F4H
; STATUS
PORT
EF79 2916 J39: ; lolA IT FOR HASTER
Efn EC 2917 IN AL.DX
; GET STATUS
EF7A A880 2:918 TEST
Al.080H
;
MASTER READY
EF7C
750C 2919 JNZ J40A I TEST_DIR
EF7E un
2920
LOOP J39
; WAIT_MASTER
EF80
800E410080 2921 OR DISKETTE_STATUS. TIME_OUT
EFaS 2922
J40: 1 RESULTS_ERROR
EF85 F9 29Z3 STC
; SET ERROR RETURN
EF86 56 2924 POP
BX
EF87 5A 29ZS
POP
ox
EFa8 59 Z9Z6 POP
ex
EF89 Cl 2927 RET
2926
2929 ;------ TEST THE DIRECTION BIT
2930
EFSA EC 2931
J40A: IN
AL.OX
I
GET STATUS REG A.GAIN
USB AS.40 2932
TEST
AL.040H 1 TEST DIRECTION SIT
EFBO 7507 2933 JHZ
J4'
; OK TO READ STATUS
EfSf
2934 J41:
;
NEC]AIl
EFeF 8001:410020 2935 OR DISKETTE_STATUS. BAD_NEe
EF9. EB£F
2936
JH'
J4. ; RESULTS_ERROR
2937
2938 1------ READ IN THE STATUS
2939
EF96 2940
J42:
i INPUT_STAT
EF96 42
2941
INC ox
I FOINT
AT DATA PORT
EF97 EC 2942 IN AL.OX I GET TH~ DATA
EF98 8805
2943 HOV {DII.At STORE THE BYTE
EF9A 47
2944
INC or
INCREMENT THE POINTER
EF9B 690AOO 2945
HOV
eX.10
lOOP
TO KILL TIME fOR NEC
A-40