IBM 5150 Hardware Reference Manual page 231

LOC OBJ LINE SOURCE
Ef'tD £67200 2716 CAll CHK_STAT_2
; GET THE INTERUPT AND SENSE INT STATUS
fEAG 7229
2717
JC J32 ; SEEK_ERROR
2718
2719 ;---- ­ DRIVE IS IN SYHCH WITH CONTROLLER. SEEK TO TRACK
2nD
fEA2
2721
J28:
fEAt 840F 2722 HOY AH,OfH
; SEEK COt1t1AND TO NEe
EEA4 E89DFF
2723
C.6.LL tlfC_OUTPUT
EfA7 6A£2
2724
HOY AH,Dl
; DR lYE NUMBER
EfA9 E896FF 2725
CALL NEC_OUTPUT
£EAC 8AE5
2726 MOV AH,CH
; TRACK tu1BER
EEAE £893FF
2727
CALL NEC_OUTPUT
fEB 1 £85£00
2728 CAll CHK_STAT_2
J GET ENDING INTERRUPT AND SENSE STATUS
2729
2730 ;----- WAIT FOR HEAD SUTlE
2731
EE84 9t
2732 PUSHF
; SAYE STATUS FLAGS
fEes B81200
2733 HOY
BX,l8 ; GET HEAD SETTLE PARAMETER
fEB8 f8BSFF
2734
CALL GET_PARM
fEBB 51
2.735 PUSH CX ; SAVE REGISTER
fE8C
2736
J29:
; HEAD_SETTlE
EEBC 892602
2737
MOV
CX,550 ; 1 HS lOOP
fEBf OAE4 ­
2736
OR AH,AH ; TEST FOR TIME EXPIRED
EECI
740b
2739 JZ J31
EEe] E2FE
2740 J30: LOOP J30 ; DELAY FOR
1
NS
EEtS FEce
2741 DEC AH
; DECREMENT THE COUNT
EEe7 ESFl
2742 JMP
J'9
; DO IT SONE NOR E
EEC9
2743 J31:
EfC9 59
2744
POP
ex
; RECOVER STATE
EEeA 90
2745
POPF
fEeB
2746
J32:
; SEEK_ERROR
EEeB C3
2747
RET
; RETURN TO CALLER
2748 SEEK ENOP
2749 ; --------------------------­ ----------------­
2750 ; DNA_SETUP
2751 THIS ROUTINE SETS UP THE DNA FOR READ/WRITE/VERIFY
2752 OPERATIONS.
2753
I
INPUT
2754 (AL) = NOOE BYTE FOR THE DNA
2755 (ES:BX) - ADDRESS TO READI'WRlTE THE DATA
2756 ; OUTPUT
2757 {AXI DESTROYED
2756
eEee
2759 DNA_SETUP PROC NEAR
EEce 51 2760 PUSH
CX ; SAVE THE REGISTER
EECD Eboe 2761 OUT DMA+12.AL ; SET THE FIRST/LAST F/F
eEeF E60a 2762 OUT ONA+Il.AL ; OUTPUT THE MOOE BYTE
fEDl aceD 2763 HOV AX,ES ; GET THE ES VALUE
fED3 8104 2764 MDV CL,4 ; SHIFT COUNT
fEOS 03eo
2765
ROL
AX.CL ; ROTATE LEFT
fED7 8A£8 2766 HOV CH .AL ; GET HIGHEST NYBLE OF ES TO CH
EED9 24FO 2767 AND AL.OFOH
; ZERO THE LOW NYBBLE FROM SEGMENT
fEoe 03e]
2766 ADD
Ax.ex
; TEST FOR CARRY FROM ADDITION
EEOD 7302 2769
JNC
J33
HOF FEes 2770 INC CH I CARRY MEANS HIGH 4 BITS MUST BE INC
fEEL 2771 J33:
fEEl 50
2772 PUSH
AX ; SAVE START ADDRESS
fEEZ £604­ 2773
OUT
DMA+4.AL
; OUTPUT LOW ADDRESS
EEE4 8AC4­
2774 NOV AL,AH
EEE6 £604
2775
OUT DHA+4,AL I OUTPUT HIGH ADDRESS
fEES 8ACS
2776 HOV AL.CH ; GET HIGH 4 BITS
fEEA 240F 2777 MiD AL.OFH
EEEC E681 2778 OUT oalH,At
; OUTPUT THE HIGH 4 BITS TO PAGE REGISTER
2779
2780 ;------ DETERMINE COUNT
2761
EEEE 8Af6
2782
MOY AH,DH ; NUNBER OF SECTORS
EEFO 2ACO 2783
sua
AL,Al
; TINES 256 INTO AX
EEFt 01E8
2784
SHR AX,I • SECTORS
*
128 INTO AX
EEF4 50
2765 PUSH AX
EEF5 880600 2766 MOV BX,6
; GET THE BYTES/SECTOR F'ARH
fEFS Ea7sFF 2787 CALL GET_PARM
EHB BAce 2788 HOV Cl,AH
; USE AS SHIFT Coutrr {(I=128. 1=256 ETC)
fEFO 58 2789 POP AX
fEFE 03EO 2790 SHL AX.CL
; MULTIPLY BY CORRECT AMOUNT
EFOO 48 2791 DEC AX
; -1 FOR DMA VALUE
EF01 50 2792
PUSH AX ; SAVE COUNT VALUE
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