[41] | 1 | ; Project name : Assembly Library |
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| 2 | ; Description : Functions for system timer related operations. |
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| 3 | |
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[376] | 4 | ; |
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| 5 | ; XTIDE Universal BIOS and Associated Tools |
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| 6 | ; Copyright (C) 2009-2010 by Tomi Tilli, 2011-2012 by XTIDE Universal BIOS Team. |
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| 7 | ; |
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| 8 | ; This program is free software; you can redistribute it and/or modify |
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| 9 | ; it under the terms of the GNU General Public License as published by |
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| 10 | ; the Free Software Foundation; either version 2 of the License, or |
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| 11 | ; (at your option) any later version. |
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| 12 | ; |
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| 13 | ; This program is distributed in the hope that it will be useful, |
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| 14 | ; but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | ; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
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| 16 | ; GNU General Public License for more details. |
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| 17 | ; Visit http://www.gnu.org/licenses/old-licenses/gpl-2.0.html |
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| 18 | ; |
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| 19 | |
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[41] | 20 | ; System timer ticks 18.2 times per second = 54.9 ms / tick |
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| 21 | TICKS_PER_HOUR EQU 65520 |
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| 22 | TICKS_PER_MINUTE EQU 1092 |
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| 23 | TICKS_PER_SECOND EQU 18 |
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| 24 | |
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| 25 | |
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| 26 | ; Section containing code |
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| 27 | SECTION .text |
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| 28 | |
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| 29 | ;-------------------------------------------------------------------- |
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| 30 | ; TimerTicks_GetHoursToAXfromTicksInDXAX |
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| 31 | ; TimerTicks_GetMinutesToAXfromTicksInDX |
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| 32 | ; TimerTicks_GetSecondsToAXfromTicksInDX |
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| 33 | ; Parameters |
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| 34 | ; DX(:AX): Timer ticks to convert |
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| 35 | ; Returns: |
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| 36 | ; AX: Hours, minutes or seconds |
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| 37 | ; DX: Remainder ticks |
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| 38 | ; Corrupts registers: |
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| 39 | ; CX |
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| 40 | ;-------------------------------------------------------------------- |
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[131] | 41 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS |
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[370] | 42 | %ifndef EXCLUDE_FROM_XTIDECFG |
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[41] | 43 | ALIGN JUMP_ALIGN |
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| 44 | TimerTicks_GetHoursToAXfromTicksInDXAX: |
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| 45 | mov cx, TICKS_PER_HOUR |
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| 46 | div cx ; Divide DX:AX by CX, Hours to AX, remainder ticks to DX |
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| 47 | ret |
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[370] | 48 | %endif ; EXCLUDE_FROM_XTIDECFG |
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[41] | 49 | |
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| 50 | ALIGN JUMP_ALIGN |
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| 51 | TimerTicks_GetMinutesToAXfromTicksInDX: |
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| 52 | xor ax, ax |
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| 53 | xchg ax, dx ; Ticks now in DX:AX |
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| 54 | mov cx, TICKS_PER_MINUTE |
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| 55 | div cx ; Divide DX:AX by CX, Minutes to AX, remainder ticks to DX |
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| 56 | ret |
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[370] | 57 | %endif ; EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS |
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[106] | 58 | |
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[41] | 59 | ALIGN JUMP_ALIGN |
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| 60 | TimerTicks_GetSecondsToAXfromTicksInDX: |
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| 61 | xchg ax, dx ; Ticks now in AX |
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| 62 | mov cl, TICKS_PER_SECOND |
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| 63 | div cl ; Divide AX by CL, Seconds to AL, remainder ticks to AH |
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| 64 | xor dx, dx |
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| 65 | xchg dl, ah ; Seconds in AX, remainder in DX |
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| 66 | ret |
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| 67 | |
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| 68 | |
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| 69 | ;-------------------------------------------------------------------- |
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| 70 | ; First tick might take 0...54.9 ms and remaining ticks |
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| 71 | ; will occur at 54.9 ms intervals. Use delay of two (or more) ticks to |
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| 72 | ; ensure at least 54.9 ms timeout. |
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| 73 | ; |
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| 74 | ; TimerTicks_InitializeTimeoutFromAX |
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| 75 | ; Parameters: |
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| 76 | ; AX: Timeout ticks (54.9 ms) before timeout |
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| 77 | ; DS:BX: Ptr to timeout variable WORD |
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| 78 | ; Returns: |
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| 79 | ; [DS:BX]: Initialized for TimerTicks_SetCarryIfTimeoutFromDSBX |
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| 80 | ; Corrupts registers: |
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| 81 | ; AX |
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| 82 | ;-------------------------------------------------------------------- |
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| 83 | ALIGN JUMP_ALIGN |
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| 84 | TimerTicks_InitializeTimeoutFromAX: |
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| 85 | mov [bx], ax ; Store timeout ticks |
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| 86 | call TimerTicks_ReadFromBdaToAX |
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[119] | 87 | add [bx], ax ; [bx] now contains end time for timeout |
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[41] | 88 | ret |
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| 89 | |
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[60] | 90 | |
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[41] | 91 | ;-------------------------------------------------------------------- |
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[60] | 92 | ; TimerTicks_GetTimeoutTicksLeftToAXfromDSBX |
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[41] | 93 | ; Parameters: |
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| 94 | ; DS:BX: Ptr to timeout variable WORD |
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| 95 | ; Returns: |
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[85] | 96 | ; AX: Number of ticks left before timeout |
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[41] | 97 | ; CF: Set if timeout |
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| 98 | ; Cleared if time left |
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| 99 | ; Corrupts registers: |
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| 100 | ; Nothing |
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| 101 | ;-------------------------------------------------------------------- |
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| 102 | ALIGN JUMP_ALIGN |
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[60] | 103 | TimerTicks_GetTimeoutTicksLeftToAXfromDSBX: |
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| 104 | push dx |
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| 105 | mov dx, [bx] |
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[41] | 106 | call TimerTicks_ReadFromBdaToAX |
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[60] | 107 | xchg ax, dx |
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| 108 | sub ax, dx ; AX = End time - current time |
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| 109 | pop dx |
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[41] | 110 | ret |
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| 111 | |
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| 112 | |
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| 113 | ;-------------------------------------------------------------------- |
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| 114 | ; TimerTicks_GetElapsedToAXandResetDSBX |
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| 115 | ; Parameters |
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| 116 | ; DS:BX: Ptr to WORD containing previous reset time |
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| 117 | ; Returns: |
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| 118 | ; AX: 54.9 ms ticks elapsed since last reset |
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| 119 | ; [DS:BX]: Reset to latest time |
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| 120 | ; Corrupts registers: |
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| 121 | ; Nothing |
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| 122 | ;-------------------------------------------------------------------- |
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[131] | 123 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS |
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[41] | 124 | ALIGN JUMP_ALIGN |
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| 125 | TimerTicks_GetElapsedToAXandResetDSBX: |
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| 126 | call TimerTicks_ReadFromBdaToAX |
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| 127 | push ax |
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| 128 | sub ax, [bx] |
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| 129 | pop WORD [bx] ; Latest time to [DS:BX] |
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| 130 | ret |
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[131] | 131 | %endif |
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[41] | 132 | |
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| 133 | ;-------------------------------------------------------------------- |
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| 134 | ; TimerTicks_GetElapsedToAXfromDSBX |
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| 135 | ; Parameters |
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| 136 | ; DS:BX: Ptr to WORD containing previous update time |
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| 137 | ; Returns: |
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| 138 | ; AX: 54.9 ms ticks elapsed since initializing [DS:BX] |
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| 139 | ; Corrupts registers: |
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| 140 | ; Nothing |
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| 141 | ;-------------------------------------------------------------------- |
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[131] | 142 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS |
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[41] | 143 | ALIGN JUMP_ALIGN |
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| 144 | TimerTicks_GetElapsedToAXfromDSBX: |
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| 145 | call TimerTicks_ReadFromBdaToAX |
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| 146 | sub ax, [bx] |
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| 147 | ret |
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[131] | 148 | %endif |
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[41] | 149 | |
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| 150 | |
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| 151 | ;-------------------------------------------------------------------- |
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| 152 | ; TimerTicks_ReadFromBdaToAX |
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| 153 | ; Parameters |
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| 154 | ; Nothing |
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| 155 | ; Returns: |
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| 156 | ; AX: System time in 54.9 ms ticks |
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| 157 | ; Corrupts registers: |
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| 158 | ; Nothing |
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| 159 | ;-------------------------------------------------------------------- |
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| 160 | ALIGN JUMP_ALIGN |
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| 161 | TimerTicks_ReadFromBdaToAX: |
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| 162 | push ds |
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| 163 | |
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| 164 | LOAD_BDA_SEGMENT_TO ds, ax |
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| 165 | mov ax, [BDA.dwTimerTicks] ; Read low WORD only |
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| 166 | |
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| 167 | pop ds |
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| 168 | ret |
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