| [41] | 1 | ; Project name : Assembly Library
|
|---|
| 2 | ; Description : Functions for managing display page.
|
|---|
| 3 |
|
|---|
| 4 | ; Section containing code
|
|---|
| 5 | SECTION .text
|
|---|
| 6 |
|
|---|
| 7 | ;--------------------------------------------------------------------
|
|---|
| 8 | ; DisplayPage_SetFromAL
|
|---|
| 9 | ; Parameters:
|
|---|
| 10 | ; AL: New display page
|
|---|
| 11 | ; DS: BDA segment (zero)
|
|---|
| 12 | ; Returns:
|
|---|
| 13 | ; Nothing
|
|---|
| 14 | ; Corrupts registers:
|
|---|
| 15 | ; AX, DX
|
|---|
| 16 | ;--------------------------------------------------------------------
|
|---|
| [194] | 17 | %ifndef EXCLUDE_FROM_XTIDE_UNIVERSAL_BIOS
|
|---|
| [41] | 18 | ALIGN JUMP_ALIGN
|
|---|
| 19 | DisplayPage_SetFromAL:
|
|---|
| 20 | xor ah, ah
|
|---|
| 21 | mul WORD [VIDEO_BDA.wBytesPerPage] ; AX = Offset to page
|
|---|
| 22 | mov [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition], ax
|
|---|
| 23 | ret
|
|---|
| [194] | 24 | %endif
|
|---|
| [41] | 25 |
|
|---|
| 26 |
|
|---|
| 27 | ;--------------------------------------------------------------------
|
|---|
| 28 | ; DisplayPage_GetColumnsToALandRowsToAH
|
|---|
| 29 | ; Parameters:
|
|---|
| 30 | ; DS: BDA segment (zero)
|
|---|
| 31 | ; Returns:
|
|---|
| 32 | ; AL: Number of columns in selected text mode
|
|---|
| 33 | ; AH: Number of rows in selected text mode
|
|---|
| 34 | ; Corrupts registers:
|
|---|
| 35 | ; Nothing
|
|---|
| 36 | ;--------------------------------------------------------------------
|
|---|
| 37 | ALIGN JUMP_ALIGN
|
|---|
| 38 | DisplayPage_GetColumnsToALandRowsToAH:
|
|---|
| 39 | mov al, [VIDEO_BDA.wColumns] ; 40 or 80
|
|---|
| 40 | mov ah, 25 ; Always 25 rows on standard text modes
|
|---|
| 41 | ret
|
|---|
| 42 |
|
|---|
| 43 |
|
|---|
| 44 | ;--------------------------------------------------------------------
|
|---|
| 45 | ; DisplayPage_SynchronizeToHardware
|
|---|
| 46 | ; Parameters:
|
|---|
| 47 | ; DS: BDA segment (zero)
|
|---|
| 48 | ; Returns:
|
|---|
| 49 | ; Nothing
|
|---|
| 50 | ; Corrupts registers:
|
|---|
| 51 | ; AX, DX
|
|---|
| 52 | ;--------------------------------------------------------------------
|
|---|
| 53 | ALIGN JUMP_ALIGN
|
|---|
| 54 | DisplayPage_SynchronizeToHardware:
|
|---|
| 55 | xor dx, dx
|
|---|
| 56 | mov ax, [VIDEO_BDA.displayContext+DISPLAY_CONTEXT.fpCursorPosition]
|
|---|
| 57 | div WORD [VIDEO_BDA.wBytesPerPage] ; AX = Page
|
|---|
| 58 |
|
|---|
| 59 | cmp al, [VIDEO_BDA.bActivePage]
|
|---|
| 60 | je SHORT .Return ; Same page, no need to synchronize
|
|---|
| 61 | mov ah, SELECT_ACTIVE_DISPLAY_PAGE
|
|---|
| 62 | int BIOS_VIDEO_INTERRUPT_10h
|
|---|
| 63 | .Return:
|
|---|
| 64 | ret
|
|---|
