[41] | 1 | ; Project name : Assembly Library |
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| 2 | ; Description : Functions for managing display context. |
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| 3 | |
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| 4 | ; Section containing code |
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| 5 | SECTION .text |
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| 6 | |
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| 7 | ;-------------------------------------------------------------------- |
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| 8 | ; DisplayContext_Initialize |
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| 9 | ; Parameters: |
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| 10 | ; DS: BDA segment (zero) |
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| 11 | ; Returns: |
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| 12 | ; Nothing |
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| 13 | ; Corrupts registers: |
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| 14 | ; AX, DX, DI |
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| 15 | ;-------------------------------------------------------------------- |
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| 16 | ALIGN JUMP_ALIGN |
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| 17 | DisplayContext_Initialize: |
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| 18 | mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], DEFAULT_CHARACTER_OUTPUT |
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| 19 | mov WORD [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCursorShape], CURSOR_NORMAL |
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[44] | 20 | mov BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], SCREEN_BACKGROUND_ATTRIBUTE |
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[101] | 21 | ; Fall to .DetectAndSetDisplaySegment |
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[41] | 22 | |
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| 23 | ;-------------------------------------------------------------------- |
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| 24 | ; .DetectAndSetDisplaySegment |
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| 25 | ; Parameters: |
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| 26 | ; DS: BDA segment (zero) |
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| 27 | ; Returns: |
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| 28 | ; Nothing |
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| 29 | ; Corrupts registers: |
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[50] | 30 | ; AX, DX |
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[41] | 31 | ;-------------------------------------------------------------------- |
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| 32 | .DetectAndSetDisplaySegment: |
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[50] | 33 | mov ax, COLOR_TEXT_SEGMENT |
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[41] | 34 | cmp BYTE [VIDEO_BDA.bMode], MDA_TEXT_MODE |
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[101] | 35 | eCMOVE ah, MONO_TEXT_SEGMENT >> 8 |
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[50] | 36 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], ax |
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[101] | 37 | ; Fall to .InitializeFlags |
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[50] | 38 | |
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| 39 | ;-------------------------------------------------------------------- |
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| 40 | ; .InitializeFlags |
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| 41 | ; Parameters: |
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| 42 | ; DS: BDA segment (zero) |
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| 43 | ; Returns: |
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| 44 | ; Nothing |
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| 45 | ; Corrupts registers: |
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| 46 | ; AX, DX |
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| 47 | ;-------------------------------------------------------------------- |
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| 48 | .InitializeFlags: |
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| 49 | mov dl, FLG_CONTEXT_ATTRIBUTES |
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| 50 | call CgaSnow_IsCgaPresent |
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| 51 | jnc SHORT .DoNotSetCgaFlag |
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| 52 | or dl, FLG_CONTEXT_CGA |
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| 53 | .DoNotSetCgaFlag: |
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| 54 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], dl |
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[101] | 55 | ; Fall to .InitializeCursor |
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[41] | 56 | |
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[101] | 57 | ;-------------------------------------------------------------------- |
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| 58 | ; .InitializeCursor |
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| 59 | ; Parameters: |
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| 60 | ; DS: BDA segment (zero) |
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| 61 | ; Returns: |
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| 62 | ; Nothing |
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| 63 | ; Corrupts registers: |
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| 64 | ; AX, DX |
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| 65 | ;-------------------------------------------------------------------- |
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| 66 | .InitializeCursor: |
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[115] | 67 | call DisplayCursor_GetHardwareCoordinatesToAX ; Coordinates before init |
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| 68 | call DisplayCursor_SetCoordinatesFromAX ; Cursor to Display Context |
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[101] | 69 | ; Fall to DisplayContext_SynchronizeToHardware |
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[41] | 70 | |
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| 71 | ;-------------------------------------------------------------------- |
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[101] | 72 | ; DisplayContext_SynchronizeToHardware |
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| 73 | ; Parameters: |
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| 74 | ; DS: BDA segment (zero) |
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| 75 | ; Returns: |
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| 76 | ; Nothing |
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| 77 | ; Corrupts registers: |
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| 78 | ; AX, DX |
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| 79 | ;-------------------------------------------------------------------- |
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| 80 | ALIGN JUMP_ALIGN |
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| 81 | DisplayContext_SynchronizeToHardware: |
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| 82 | call DisplayPage_SynchronizeToHardware |
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| 83 | call DisplayCursor_SynchronizeShapeToHardware |
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| 84 | jmp DisplayCursor_SynchronizeCoordinatesToHardware |
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| 85 | |
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| 86 | |
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| 87 | ;-------------------------------------------------------------------- |
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[41] | 88 | ; DisplayContext_Push |
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| 89 | ; Parameters: |
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| 90 | ; Nothing |
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| 91 | ; Returns: |
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| 92 | ; Nothing |
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| 93 | ; Corrupts registers: |
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| 94 | ; AX, DI |
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| 95 | ;-------------------------------------------------------------------- |
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| 96 | ALIGN JUMP_ALIGN |
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| 97 | DisplayContext_Push: |
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| 98 | mov di, ds ; Backup DS |
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| 99 | LOAD_BDA_SEGMENT_TO ds, ax |
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| 100 | pop ax ; Pop return address |
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| 101 | |
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| 102 | %assign i 0 |
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| 103 | %rep DISPLAY_CONTEXT_size / 2 |
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| 104 | push WORD [VIDEO_BDA.displayContext + i] |
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| 105 | %assign i i+2 |
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| 106 | %endrep |
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| 107 | |
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| 108 | mov ds, di ; Restore DS |
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| 109 | jmp ax |
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| 110 | |
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| 111 | ;-------------------------------------------------------------------- |
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| 112 | ; DisplayContext_Pop |
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| 113 | ; Parameters: |
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| 114 | ; Nothing |
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| 115 | ; Returns: |
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| 116 | ; Nothing |
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| 117 | ; Corrupts registers: |
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| 118 | ; AX, DI |
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| 119 | ;-------------------------------------------------------------------- |
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| 120 | ALIGN JUMP_ALIGN |
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| 121 | DisplayContext_Pop: |
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| 122 | mov di, ds ; Backup DS |
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| 123 | LOAD_BDA_SEGMENT_TO ds, ax |
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| 124 | pop ax ; Pop return address |
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| 125 | |
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| 126 | %assign i DISPLAY_CONTEXT_size-2 |
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| 127 | %rep DISPLAY_CONTEXT_size / 2 |
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| 128 | pop WORD [VIDEO_BDA.displayContext + i] |
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| 129 | %assign i i-2 |
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| 130 | %endrep |
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| 131 | |
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| 132 | push ax ; Push return address |
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| 133 | push dx |
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| 134 | call DisplayContext_SynchronizeToHardware |
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| 135 | pop dx |
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| 136 | mov ds, di ; Restore DS |
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| 137 | ret |
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| 138 | |
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| 139 | |
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| 140 | ;-------------------------------------------------------------------- |
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[52] | 141 | ; DisplayContext_PrepareOffScreenBufferInESBXwithLengthInCX |
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[48] | 142 | ; Parameters: |
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[52] | 143 | ; CX: Off screen buffer length in characters |
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| 144 | ; ES:BX: Ptr to off screen buffer |
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[48] | 145 | ; Returns: |
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| 146 | ; Nothing |
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| 147 | ; Corrupts registers: |
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[52] | 148 | ; AX, DI |
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[48] | 149 | ;-------------------------------------------------------------------- |
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| 150 | ALIGN JUMP_ALIGN |
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[52] | 151 | DisplayContext_PrepareOffScreenBufferInESBXwithLengthInCX: |
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[48] | 152 | push ds |
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| 153 | |
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| 154 | LOAD_BDA_SEGMENT_TO ds, di |
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| 155 | xchg ax, bx |
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| 156 | mov bx, es |
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| 157 | call DisplayContext_SetCharacterPointerFromBXAX ; ES:DI now has the pointer |
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| 158 | |
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| 159 | mov bl, ATTRIBUTES_NOT_USED |
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| 160 | mov ax, BUFFER_OUTPUT_WITH_CHAR_ONLY |
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| 161 | call DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL |
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[52] | 162 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], cx |
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[48] | 163 | |
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| 164 | mov bx, di |
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| 165 | pop ds |
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| 166 | ret |
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| 167 | |
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| 168 | |
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| 169 | ;-------------------------------------------------------------------- |
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[41] | 170 | ; DisplayContext_SetCharacterPointerFromBXAX |
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| 171 | ; Parameters: |
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| 172 | ; BX:AX: Ptr to destination for next character to output |
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| 173 | ; DS: BDA segment (zero) |
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| 174 | ; Returns: |
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[48] | 175 | ; ES:DI: Pointer that was in BX:AX |
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[41] | 176 | ; Corrupts registers: |
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| 177 | ; AX |
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| 178 | ;-------------------------------------------------------------------- |
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| 179 | ALIGN JUMP_ALIGN |
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| 180 | DisplayContext_SetCharacterPointerFromBXAX: |
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| 181 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax |
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| 182 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2], bx |
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| 183 | xchg di, ax |
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| 184 | mov es, bx |
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| 185 | ret |
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| 186 | |
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| 187 | |
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| 188 | ;-------------------------------------------------------------------- |
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| 189 | ; DisplayContext_GetCharacterPointerToBXAX |
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| 190 | ; Parameters: |
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| 191 | ; DS: BDA segment (zero) |
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| 192 | ; Returns: |
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| 193 | ; BX:AX: Ptr to destination for next character to output |
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| 194 | ; Corrupts registers: |
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| 195 | ; Nothing |
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| 196 | ;-------------------------------------------------------------------- |
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| 197 | ALIGN JUMP_ALIGN |
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| 198 | DisplayContext_GetCharacterPointerToBXAX: |
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| 199 | mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition] |
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| 200 | mov bx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition+2] |
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| 201 | ret |
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| 202 | |
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| 203 | |
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| 204 | ;-------------------------------------------------------------------- |
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[45] | 205 | ; DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL |
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[41] | 206 | ; Parameters: |
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| 207 | ; AX: Offset to character output function |
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[45] | 208 | ; BL: Attribute Flag |
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[41] | 209 | ; DS: BDA segment (zero) |
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| 210 | ; Returns: |
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| 211 | ; Nothing |
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| 212 | ; Corrupts registers: |
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[50] | 213 | ; BL |
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[41] | 214 | ;-------------------------------------------------------------------- |
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| 215 | ALIGN JUMP_ALIGN |
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[45] | 216 | DisplayContext_SetCharOutputFunctionFromAXwithAttribFlagInBL: |
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[50] | 217 | and bl, FLG_CONTEXT_ATTRIBUTES |
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| 218 | and BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], ~FLG_CONTEXT_ATTRIBUTES |
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| 219 | or [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], bl |
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[41] | 220 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fnCharOut], ax |
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| 221 | ret |
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| 222 | |
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| 223 | |
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| 224 | ;-------------------------------------------------------------------- |
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| 225 | ; DisplayContext_SetCharacterAttributeFromAL |
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| 226 | ; Parameters: |
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| 227 | ; AL: Character attribute |
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| 228 | ; DS: BDA segment (zero) |
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| 229 | ; Returns: |
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| 230 | ; Nothing |
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| 231 | ; Corrupts registers: |
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| 232 | ; Nothing |
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| 233 | ;-------------------------------------------------------------------- |
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| 234 | ALIGN JUMP_ALIGN |
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| 235 | DisplayContext_SetCharacterAttributeFromAL: |
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| 236 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bAttribute], al |
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| 237 | ret |
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| 238 | |
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| 239 | |
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| 240 | ;-------------------------------------------------------------------- |
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| 241 | ; DisplayContext_SetCharacterOutputParameterFromAX |
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| 242 | ; Parameters: |
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| 243 | ; AX: Parameter for Character Output function |
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| 244 | ; DS: BDA segment (zero) |
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| 245 | ; Returns: |
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| 246 | ; Nothing |
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| 247 | ; Corrupts registers: |
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| 248 | ; Nothing |
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| 249 | ;-------------------------------------------------------------------- |
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| 250 | ALIGN JUMP_ALIGN |
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| 251 | DisplayContext_SetCharacterOutputParameterFromAX: |
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| 252 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam], ax |
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| 253 | ret |
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| 254 | |
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| 255 | ;-------------------------------------------------------------------- |
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| 256 | ; DisplayContext_GetCharacterOutputParameterToDX |
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| 257 | ; Parameters: |
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| 258 | ; DS: BDA segment (zero) |
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| 259 | ; Returns: |
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| 260 | ; DX: User parameter for Character Output function |
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| 261 | ; Corrupts registers: |
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| 262 | ; Nothing |
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| 263 | ;-------------------------------------------------------------------- |
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| 264 | ALIGN JUMP_ALIGN |
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| 265 | DisplayContext_GetCharacterOutputParameterToDX: |
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| 266 | mov dx, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.wCharOutParam] |
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| 267 | ret |
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[44] | 268 | |
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| 269 | |
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| 270 | ;-------------------------------------------------------------------- |
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| 271 | ; DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX |
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| 272 | ; Parameters: |
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| 273 | ; AX: Offset in bytes from some character to another |
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| 274 | ; DS: BDA segment (zero) |
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| 275 | ; Returns: |
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| 276 | ; AX: Offset in characters from some character to another |
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| 277 | ; Corrupts registers: |
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| 278 | ; Nothing |
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| 279 | ;-------------------------------------------------------------------- |
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| 280 | ALIGN JUMP_ALIGN |
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| 281 | DisplayContext_GetCharacterOffsetToAXfromByteOffsetInAX: |
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| 282 | test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES |
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| 283 | jz SHORT ReturnOffsetInAX |
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| 284 | sar ax, 1 ; BYTE count to WORD count |
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| 285 | ret |
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| 286 | |
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| 287 | ;-------------------------------------------------------------------- |
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| 288 | ; DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX |
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| 289 | ; Parameters: |
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| 290 | ; AX: Offset in characters from some character to another |
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| 291 | ; DS: BDA segment (zero) |
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| 292 | ; Returns: |
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| 293 | ; AX: Offset in bytes from some character to another |
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| 294 | ; Corrupts registers: |
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| 295 | ; Nothing |
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| 296 | ;-------------------------------------------------------------------- |
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| 297 | ALIGN JUMP_ALIGN |
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| 298 | DisplayContext_GetByteOffsetToAXfromCharacterOffsetInAX: |
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| 299 | test BYTE [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.bFlags], FLG_CONTEXT_ATTRIBUTES |
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| 300 | jz SHORT ReturnOffsetInAX |
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| 301 | sal ax, 1 ; WORD count to BYTE count |
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| 302 | ALIGN JUMP_ALIGN, ret |
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| 303 | ReturnOffsetInAX: |
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| 304 | ret |
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