IBM 5150 PC Technical Reference (6025005, August, 1981) (PDF)

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
fEA2 2721 J28:
2719 ;----­ DRIVE IS IN SYHCH WITH CONTROLLER. SEEK TO TRACK
2nD
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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