| 1 | ; Project name : Assembly Library |
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| 2 | ; Description : Functions for managing display page. |
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| 3 | |
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| 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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| 20 | ; Section containing code |
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| 21 | SECTION .text |
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| 22 | |
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| 23 | ;-------------------------------------------------------------------- |
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| 24 | ; DisplayPage_SetFromAL |
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| 25 | ; Parameters: |
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| 26 | ; AL: New display page |
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| 27 | ; DS: BDA segment (zero) |
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| 28 | ; Returns: |
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| 29 | ; Nothing |
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| 30 | ; Corrupts registers: |
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| 31 | ; AX, DX |
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| 32 | ;-------------------------------------------------------------------- |
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| 33 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS OR EXCLUDE_FROM_XTIDECFG |
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| 34 | ALIGN DISPLAY_JUMP_ALIGN |
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| 35 | DisplayPage_SetFromAL: |
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| 36 | xor ah, ah |
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| 37 | mul WORD [VIDEO_BDA.wBytesPerPage] ; AX = Offset to page |
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| 38 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax |
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| 39 | ret |
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| 40 | %endif |
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| 41 | |
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| 42 | |
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| 43 | ;-------------------------------------------------------------------- |
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| 44 | ; DisplayPage_GetColumnsToALandRowsToAH |
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| 45 | ; Parameters: |
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| 46 | ; DS: BDA segment (zero) |
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| 47 | ; Returns: |
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| 48 | ; AL: Number of columns in selected text mode |
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| 49 | ; AH: Number of rows in selected text mode |
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| 50 | ; Corrupts registers: |
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| 51 | ; Nothing |
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| 52 | ;-------------------------------------------------------------------- |
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| 53 | ALIGN DISPLAY_JUMP_ALIGN |
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| 54 | DisplayPage_GetColumnsToALandRowsToAH: |
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| 55 | mov al, [VIDEO_BDA.wColumns] ; 40 or 80 |
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| 56 | mov ah, 25 ; Always 25 rows on standard text modes |
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| 57 | ret |
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| 58 | |
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| 59 | |
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| 60 | ;-------------------------------------------------------------------- |
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| 61 | ; DisplayPage_SynchronizeToHardware |
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| 62 | ; Parameters: |
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| 63 | ; DS: BDA segment (zero) |
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| 64 | ; Returns: |
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| 65 | ; Nothing |
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| 66 | ; Corrupts registers: |
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| 67 | ; AX, DX |
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| 68 | ;-------------------------------------------------------------------- |
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| 69 | ALIGN DISPLAY_JUMP_ALIGN |
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| 70 | DisplayPage_SynchronizeToHardware: |
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| 71 | xor dx, dx |
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| 72 | mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition] |
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| 73 | div WORD [VIDEO_BDA.wBytesPerPage] ; AX = Page |
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| 74 | |
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| 75 | cmp al, [VIDEO_BDA.bActivePage] |
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| 76 | je SHORT .Return ; Same page, no need to synchronize |
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| 77 | mov ah, SELECT_ACTIVE_DISPLAY_PAGE |
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| 78 | int BIOS_VIDEO_INTERRUPT_10h |
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| 79 | .Return: |
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| 80 | ret |
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