[41] | 1 | ; File name : DisplayContext.asm |
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| 2 | ; Project name : Assembly Library |
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| 3 | ; Created date : 25.6.2010 |
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[50] | 4 | ; Last update : 9.10.2010 |
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[41] | 5 | ; Author : Tomi Tilli |
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| 6 | ; Description : Functions for managing display context. |
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| 7 | |
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| 8 | ; Section containing code |
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| 9 | SECTION .text |
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| 10 | |
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| 11 | ;-------------------------------------------------------------------- |
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| 12 | ; DisplayContext_Initialize |
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| 13 | ; Parameters: |
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| 14 | ; DS: BDA segment (zero) |
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| 15 | ; Returns: |
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| 16 | ; Nothing |
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| 17 | ; Corrupts registers: |
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| 18 | ; AX, DX, DI |
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| 19 | ;-------------------------------------------------------------------- |
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| 20 | ALIGN JUMP_ALIGN |
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| 21 | DisplayContext_Initialize: |
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[50] | 22 | call .DetectAndSetDisplaySegment ; and .InitializeFlags |
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[41] | 23 | mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], DEFAULT_CHARACTER_OUTPUT |
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| 24 | mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape], CURSOR_NORMAL |
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[44] | 25 | mov BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], SCREEN_BACKGROUND_ATTRIBUTE |
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[41] | 26 | xor ax, ax |
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| 27 | call DisplayCursor_SetCoordinatesFromAX |
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[50] | 28 | jmp DisplayContext_SynchronizeToHardware |
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[41] | 29 | |
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| 30 | ;-------------------------------------------------------------------- |
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| 31 | ; .DetectAndSetDisplaySegment |
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| 32 | ; Parameters: |
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| 33 | ; DS: BDA segment (zero) |
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| 34 | ; Returns: |
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| 35 | ; Nothing |
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| 36 | ; Corrupts registers: |
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[50] | 37 | ; AX, DX |
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[41] | 38 | ;-------------------------------------------------------------------- |
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| 39 | .DetectAndSetDisplaySegment: |
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[50] | 40 | mov ax, COLOR_TEXT_SEGMENT |
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[41] | 41 | cmp BYTE [VIDEO_BDA.bMode], MDA_TEXT_MODE |
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[50] | 42 | jne SHORT .StoreSegmentToDisplayContext |
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| 43 | mov ax, MONO_TEXT_SEGMENT |
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| 44 | .StoreSegmentToDisplayContext: |
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| 45 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], ax |
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| 46 | ; Fall to InitializeFlags |
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| 47 | |
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| 48 | ;-------------------------------------------------------------------- |
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| 49 | ; .InitializeFlags |
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| 50 | ; Parameters: |
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| 51 | ; DS: BDA segment (zero) |
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| 52 | ; Returns: |
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| 53 | ; Nothing |
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| 54 | ; Corrupts registers: |
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| 55 | ; AX, DX |
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| 56 | ;-------------------------------------------------------------------- |
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| 57 | .InitializeFlags: |
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| 58 | mov dl, FLG_CONTEXT_ATTRIBUTES |
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| 59 | call CgaSnow_IsCgaPresent |
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| 60 | jnc SHORT .DoNotSetCgaFlag |
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| 61 | or dl, FLG_CONTEXT_CGA |
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| 62 | .DoNotSetCgaFlag: |
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| 63 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], dl |
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[41] | 64 | ret |
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| 65 | |
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| 66 | |
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| 67 | ;-------------------------------------------------------------------- |
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| 68 | ; DisplayContext_Push |
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| 69 | ; Parameters: |
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| 70 | ; Nothing |
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| 71 | ; Returns: |
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| 72 | ; Nothing |
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| 73 | ; Corrupts registers: |
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| 74 | ; AX, DI |
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| 75 | ;-------------------------------------------------------------------- |
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| 76 | ALIGN JUMP_ALIGN |
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| 77 | DisplayContext_Push: |
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| 78 | mov di, ds ; Backup DS |
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| 79 | LOAD_BDA_SEGMENT_TO ds, ax |
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| 80 | pop ax ; Pop return address |
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| 81 | |
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| 82 | %assign i 0 |
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| 83 | %rep DISPLAY_CONTEXT_size / 2 |
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| 84 | push WORD [VIDEO_BDA.displayContext + i] |
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| 85 | %assign i i+2 |
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| 86 | %endrep |
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| 87 | |
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| 88 | mov ds, di ; Restore DS |
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| 89 | jmp ax |
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| 90 | |
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| 91 | ;-------------------------------------------------------------------- |
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| 92 | ; DisplayContext_Pop |
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| 93 | ; Parameters: |
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| 94 | ; Nothing |
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| 95 | ; Returns: |
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| 96 | ; Nothing |
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| 97 | ; Corrupts registers: |
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| 98 | ; AX, DI |
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| 99 | ;-------------------------------------------------------------------- |
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| 100 | ALIGN JUMP_ALIGN |
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| 101 | DisplayContext_Pop: |
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| 102 | mov di, ds ; Backup DS |
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| 103 | LOAD_BDA_SEGMENT_TO ds, ax |
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| 104 | pop ax ; Pop return address |
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| 105 | |
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| 106 | %assign i DISPLAY_CONTEXT_size-2 |
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| 107 | %rep DISPLAY_CONTEXT_size / 2 |
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| 108 | pop WORD [VIDEO_BDA.displayContext + i] |
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| 109 | %assign i i-2 |
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| 110 | %endrep |
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| 111 | |
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| 112 | push ax ; Push return address |
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| 113 | push dx |
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| 114 | call DisplayContext_SynchronizeToHardware |
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| 115 | pop dx |
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| 116 | mov ds, di ; Restore DS |
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| 117 | ret |
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| 118 | |
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| 119 | |
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| 120 | ;-------------------------------------------------------------------- |
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[48] | 121 | ; DisplayContext_PrepareOffScreenBufferInESBXtoESDI |
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| 122 | ; Parameters: |
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| 123 | ; BX:AX: Ptr to off screen buffer |
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| 124 | ; Returns: |
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| 125 | ; Nothing |
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| 126 | ; Corrupts registers: |
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| 127 | ; AX |
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| 128 | ;-------------------------------------------------------------------- |
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| 129 | ALIGN JUMP_ALIGN |
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| 130 | DisplayContext_PrepareOffScreenBufferInESBXtoESDI: |
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| 131 | push ds |
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| 132 | |
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| 133 | LOAD_BDA_SEGMENT_TO ds, di |
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| 134 | xchg ax, bx |
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| 135 | mov bx, es |
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| 136 | call DisplayContext_SetCharacterPointerFromBXAX ; ES:DI now has the pointer |
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| 137 | |
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| 138 | mov bl, ATTRIBUTES_NOT_USED |
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| 139 | mov ax, BUFFER_OUTPUT_WITH_CHAR_ONLY |
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| 140 | call DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL |
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| 141 | |
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| 142 | mov bx, di |
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| 143 | pop ds |
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| 144 | ret |
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| 145 | |
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| 146 | |
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| 147 | ;-------------------------------------------------------------------- |
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[41] | 148 | ; DisplayContext_SynchronizeToHardware |
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| 149 | ; Parameters: |
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| 150 | ; DS: BDA segment (zero) |
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| 151 | ; Returns: |
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| 152 | ; Nothing |
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| 153 | ; Corrupts registers: |
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| 154 | ; AX, DX |
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| 155 | ;-------------------------------------------------------------------- |
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| 156 | ALIGN JUMP_ALIGN |
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| 157 | DisplayContext_SynchronizeToHardware: |
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| 158 | call DisplayPage_SynchronizeToHardware |
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| 159 | call DisplayCursor_SynchronizeShapeToHardware |
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| 160 | jmp DisplayCursor_SynchronizeCoordinatesToHardware |
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| 161 | |
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| 162 | |
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| 163 | ;-------------------------------------------------------------------- |
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| 164 | ; DisplayContext_SetCharacterPointerFromBXAX |
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| 165 | ; Parameters: |
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| 166 | ; BX:AX: Ptr to destination for next character to output |
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| 167 | ; DS: BDA segment (zero) |
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| 168 | ; Returns: |
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[48] | 169 | ; ES:DI: Pointer that was in BX:AX |
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[41] | 170 | ; Corrupts registers: |
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| 171 | ; AX |
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| 172 | ;-------------------------------------------------------------------- |
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| 173 | ALIGN JUMP_ALIGN |
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| 174 | DisplayContext_SetCharacterPointerFromBXAX: |
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| 175 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax |
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| 176 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], bx |
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| 177 | xchg di, ax |
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| 178 | mov es, bx |
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| 179 | ret |
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| 180 | |
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| 181 | |
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| 182 | ;-------------------------------------------------------------------- |
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| 183 | ; DisplayContext_GetCharacterPointerToBXAX |
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| 184 | ; Parameters: |
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| 185 | ; DS: BDA segment (zero) |
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| 186 | ; Returns: |
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| 187 | ; BX:AX: Ptr to destination for next character to output |
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| 188 | ; Corrupts registers: |
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| 189 | ; Nothing |
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| 190 | ;-------------------------------------------------------------------- |
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| 191 | ALIGN JUMP_ALIGN |
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| 192 | DisplayContext_GetCharacterPointerToBXAX: |
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| 193 | mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition] |
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| 194 | mov bx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2] |
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| 195 | ret |
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| 196 | |
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| 197 | |
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| 198 | ;-------------------------------------------------------------------- |
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[45] | 199 | ; DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL |
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[41] | 200 | ; Parameters: |
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| 201 | ; AX: Offset to character output function |
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[45] | 202 | ; BL: Attribute Flag |
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[41] | 203 | ; DS: BDA segment (zero) |
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| 204 | ; Returns: |
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| 205 | ; Nothing |
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| 206 | ; Corrupts registers: |
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[50] | 207 | ; BL |
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[41] | 208 | ;-------------------------------------------------------------------- |
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| 209 | ALIGN JUMP_ALIGN |
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[45] | 210 | DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL: |
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[50] | 211 | and bl, FLG_CONTEXT_ATTRIBUTES |
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| 212 | and BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], ~FLG_CONTEXT_ATTRIBUTES |
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| 213 | or [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], bl |
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[41] | 214 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], ax |
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| 215 | ret |
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| 216 | |
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| 217 | |
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| 218 | ;-------------------------------------------------------------------- |
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| 219 | ; DisplayContext_SetCharacterAttributeFromAL |
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| 220 | ; Parameters: |
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| 221 | ; AL: Character attribute |
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| 222 | ; DS: BDA segment (zero) |
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| 223 | ; Returns: |
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| 224 | ; Nothing |
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| 225 | ; Corrupts registers: |
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| 226 | ; Nothing |
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| 227 | ;-------------------------------------------------------------------- |
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| 228 | ALIGN JUMP_ALIGN |
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| 229 | DisplayContext_SetCharacterAttributeFromAL: |
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| 230 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], al |
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| 231 | ret |
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| 232 | |
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| 233 | |
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| 234 | ;-------------------------------------------------------------------- |
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| 235 | ; DisplayContext_SetCharacterOutputParameterFromAX |
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| 236 | ; Parameters: |
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| 237 | ; AX: Parameter for Character Output function |
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| 238 | ; DS: BDA segment (zero) |
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| 239 | ; Returns: |
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| 240 | ; Nothing |
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| 241 | ; Corrupts registers: |
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| 242 | ; Nothing |
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| 243 | ;-------------------------------------------------------------------- |
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| 244 | ALIGN JUMP_ALIGN |
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| 245 | DisplayContext_SetCharacterOutputParameterFromAX: |
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| 246 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], ax |
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| 247 | ret |
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| 248 | |
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| 249 | ;-------------------------------------------------------------------- |
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| 250 | ; DisplayContext_GetCharacterOutputParameterToDX |
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| 251 | ; Parameters: |
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| 252 | ; DS: BDA segment (zero) |
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| 253 | ; Returns: |
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| 254 | ; DX: User parameter for Character Output function |
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| 255 | ; Corrupts registers: |
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| 256 | ; Nothing |
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| 257 | ;-------------------------------------------------------------------- |
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| 258 | ALIGN JUMP_ALIGN |
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| 259 | DisplayContext_GetCharacterOutputParameterToDX: |
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| 260 | mov dx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam] |
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| 261 | ret |
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[44] | 262 | |
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| 263 | |
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| 264 | ;-------------------------------------------------------------------- |
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| 265 | ; DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX |
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| 266 | ; Parameters: |
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| 267 | ; AX: Offset in bytes from some character to another |
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| 268 | ; DS: BDA segment (zero) |
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| 269 | ; Returns: |
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| 270 | ; AX: Offset in characters from some character to another |
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| 271 | ; Corrupts registers: |
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| 272 | ; Nothing |
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| 273 | ;-------------------------------------------------------------------- |
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| 274 | ALIGN JUMP_ALIGN |
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| 275 | DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX: |
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| 276 | test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES |
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| 277 | jz SHORT ReturnOffsetInAX |
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| 278 | sar ax, 1 ; BYTE count to WORD count |
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| 279 | ret |
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| 280 | |
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| 281 | ;-------------------------------------------------------------------- |
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| 282 | ; DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX |
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| 283 | ; Parameters: |
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| 284 | ; AX: Offset in characters from some character to another |
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| 285 | ; DS: BDA segment (zero) |
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| 286 | ; Returns: |
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| 287 | ; AX: Offset in bytes from some character to another |
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| 288 | ; Corrupts registers: |
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| 289 | ; Nothing |
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| 290 | ;-------------------------------------------------------------------- |
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| 291 | ALIGN JUMP_ALIGN |
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| 292 | DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX: |
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| 293 | test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES |
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| 294 | jz SHORT ReturnOffsetInAX |
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| 295 | sal ax, 1 ; WORD count to BYTE count |
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| 296 | ALIGN JUMP_ALIGN, ret |
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| 297 | ReturnOffsetInAX: |
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| 298 | ret |
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