Programmer 7500

home *** CD-ROM | disk | FTP | other *** search

/ Programmer 7500 / MAX_PROGRAMMERS.iso / INFO / EMULATRS / APL2EM.ZIP / CGA.ASM < prev next >

Wrap

Assembly Source File | 1990-03-30 | 48.6 KB | 1,311 lines

Page 58,132 Title CGA.ASM Apple CGA Video Routines ;****************************************************************************** ; ; Name: CGA.ASM Apple CGA Video Routines ; ; Group: Emulator ; ; Revision: 1.00 ; ; Date: January 30, 1988 ; ; Author: Randy W. Spurlock ; ;****************************************************************************** ; ; Module Functional Description: ; ; This module contains all the code for the Apple ; CGA video routines. ; ;****************************************************************************** ; ; Changes: ; ; DATE REVISION DESCRIPTION ; -------- -------- ------------------------------------------------------- ; 1/30/88 1.00 Original ; ;****************************************************************************** Page ; ; Public Declarations ; Public CGA_Text_1 ; Low resolution/text page 1 write Public CGA_Text_2 ; Low resolution/text page 2 write Public CGA_Graph_1 ; High resolution page 1 write Public CGA_Graph_2 ; High resolution page 2 write Public CGA_Text_Off ; Text mode off (Graphics) Public CGA_Text_On ; Text mode on (Text) Public CGA_Mixed_Off ; Mixed off (Text / Graphics) Public CGA_Mixed_On ; Mixed on (Text & Graphics) Public CGA_Page_1 ; Select video page 1 (Text & Graphics) Public CGA_Page_2 ; Select video page 2 (Text & Graphics) Public CGA_Low_Res ; Select low resolution (Graphics) Public CGA_High_Res ; Select high resolution (Graphics) Public CGA_Restore ; CGA restore screen routine ; ; External Declarations ; Extrn Cursor_Off:Near ; Turn cursor off routine (VIDEO) Extrn Cursor_On:Near ; Turn cursor on routine (VIDEO) Extrn Blink_Off:Near ; Turn blink off routine (VIDEO) Extrn Blink_On:Near ; Turn blink on routine (VIDEO) Extrn Set_Address:Near ; Set video address routine (VIDEO) Extrn Text_Address:Word ; Text address mapping table (VIDEO) Extrn Macro_Table:Word ; Text macro table (VIDEO) Extrn Char_Table:Word ; Text character mapping table (VIDEO) Extrn CGA_Address:Word ; CGA graphics address table (VIDEO) Extrn CGA_Slice:Word ; CGA graphics macro/slice table(VIDEO) Extrn Reverse_Table:Byte ; Bit reversal table (VIDEO) Extrn Even_Table:Word ; Even column bit exp. table (VIDEO) Extrn Odd_Table:Word ; Odd column bit exp. table (VIDEO) Extrn Column_Table:Word ; Column exp. selection table (VIDEO) Extrn CGA_Shift:Byte ; CGA bit shift table (VIDEO) Extrn Map_Table:Byte ; Low res. color mapping table (VIDEO) Extrn Video_Flag:Byte ; Video system flag byte (DATA) ; ; LOCAL Equates ; TEXT_PAGE_1 Equ 04h ; Starting text page 1 page value TEXT_PAGE_2 Equ 08h ; Starting text page 2 page value GRAPH_PAGE_1 Equ 20h ; Starting graphics page 1 page value GRAPH_PAGE_2 Equ 40h ; Starting graphics page 2 page value TEXT_ADDRESS_1 Equ 0400h ; Starting text page 1 address value TEXT_ADDRESS_2 Equ 0800h ; Starting text page 2 address value GRAPH_ADDRESS_1 Equ 2000h ; Starting graphics page 1 address value GRAPH_ADDRESS_2 Equ 4000h ; Starting graphics page 2 address value BASE_ADDRESS Equ 0000h ; Base video memory address BLOCK_CHAR Equ 0DFh ; Low resolution block character value SLICE_COUNT Equ 08h ; Slice count value (8 = 192 Lines) MACRO_COUNT Equ 08h ; Macro count value (8 = 24 Rows) ROW_COUNT Equ 03h ; Row count value (3 = 3 Rows) CHAR_COUNT Equ 28h ; Character column count (40 Bytes) BYTE_COUNT Equ 0Ah ; Graphics byte count (10 = 40 Bytes) MACRO_OFFSET Equ 08h ; Macro offset value (Screen holes [8]) NEXT_OFFSET Equ 50h ; Next row offset value (80) ROW_OFFSET Equ 0230h ; Row offset value (7 * 40 * 2) NEXT_MACRO Equ 0140h ; Next macro set offset value (Graphics) NEXT_ROW Equ 09BAh ; Next row offset value (Graphics) LINE_MASK Equ 2000h ; Next line XOR mask value TEXT_MASK Equ 07FFh ; Text destination mask value TEXT_MODE Equ 00h ; Text mode value (40 x 25) GRAPH_MODE Equ 04h ; Graphics mode value (320 x 200) COLOR_MASK Equ 007Fh ; Color bit mask value WORD_MASK Equ 0FFFCh ; Word mask initial value BYTE_MASK Equ 0FCh ; Byte mask initial value ADDRESS_MASK Equ 03h ; Address bits mask value (Mod 4) ODD_COLUMN Equ 0001h ; Odd column test mask value BYTE_OFFSET Equ 02h ; Byte offset value ; ; Define any include files needed ; Include Macros.inc ; Include the macro definitions Include Equates.inc ; Include the equate definitions .286c ; Include 80286 instructions Page ; ; Define the emulator code segment ; Emulate Segment Word Public 'EMULATE' ; Emulator code segment Assume cs:Emulate, ds:Nothing, es:Nothing Subttl CGA_Text_1 Low Resolution/Text Page 1 Write Page + ;****************************************************************************** ; ; CGA_Text_1(Effective_Address, Value) ; ; Write the memory location value (Byte) ; If this is a text mode and page 1 ; Save the required registers ; Save the character table index value ; Set base text video address ; Calculate macro line and offset values ; Load offset value from offset table ; If this is NOT a screen hole ; Load macro line value from macro table ; Compute the actual screen address ; Lookup the character/attribute values ; Store the character to the screen ; Endif this is a screen hole ; Restore the required registers ; Else this is a graphics mode ; If this is low resolution graphics mode page 1 ; Save the required registers ; Save the graphics byte index value ; Set base text video address ; Calculate macro line and offset values ; Load offset value from offset table ; If this is NOT a screen hole ; Load macro line value from macro table ; Compute the actual screen address ; Lookup the graphics mapping value ; Force character code to a half block ; Store the character to the screen ; Endif this is a screen hole ; Restore the required registers ; Endif for mode value ; Return to the caller ; ; Registers on Entry: ; ; AL - Memory value ; DS:DI - 65C02 Effective address ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; DI - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Text_1 Proc Near ; Low res/text page 1 write procedure mov ds:[di],al ; Write the memory location test cs:[Video_Flag],VIDEO_MODE+PAGE_NUMBER jnz Low_Check_1 ; Jump if NOT text mode page 1 Save bx ; Save the required registers xor ah,ah ; Convert character to full word shl ax,1 ; Convert character to table index mov bp,ax ; Save character table index in BP mov ax,di ; Get the effective memory address sub ah,TEXT_PAGE_1 ; Subtract off the starting value shl ax,1 ; Move macro number into AH register xor bh,bh ; Setup to index through video tables mov bl,al ; Convert offset into table index mov di,cs:[bx+Text_Address] ; Get the text offset table value inc di ; Increment for screen hole check js Text_1_Hole ; Jump if this is a screen hole mov bl,ah ; Get macro number into BL register shl bx,1 ; Convert macro number into table index add di,cs:[bx+Macro_Table] ; Compute the actual screen address mov ax,cs:[bp+Char_Table] ; Lookup the correct character value stosw ; Store character value onto screen Text_1_Hole: Restore bx ; Restore the required registers Text_Done_1: ret ; Return to the caller Low_Check_1: test cs:[Video_Flag],RESOLUTION+PAGE_NUMBER jnz Low_Done_1 ; Jump if NOT low resolution page 1 Save bx ; Save the required registers mov ah,al ; Move graphics byte to AH register mov bp,ax ; Save graphices byte value in BP mov ax,di ; Get the effective memory address sub ah,TEXT_PAGE_1 ; Subtract off the starting value shl ax,1 ; Move macro number in AH register xor bh,bh ; Setup to index through video tables mov bl,al ; Convert offset into table index mov di,cs:[bx+Text_Address] ; Get the text offset table value inc di ; Increment for screen hole check js Low_1_Hole ; Jump if this is a screen hole mov bl,ah ; Get macro number into BL register shl bx,1 ; Convert macro number into table index add di,cs:[bx+Macro_Table] ; Compute the actual screen offset mov ax,bp ; Restore the graphics byte value mov al,BLOCK_CHAR ; Force character to block character stosw ; Store graphics value onto screen Low_1_Hole: Restore bx ; Restore the required registers Low_Done_1: ret ; Return to the caller CGA_Text_1 Endp ; End of the CGA_Text_1 procedure Subttl CGA_Text_2 Low Resolution/Text Page 2 Write Page + ;****************************************************************************** ; ; CGA_Text_2(Effective_Address, Value) ; ; Write the memory location value (Byte) ; If this is a text mode and page 2 ; Save the required registers ; Save the character table index value ; Set base text video address ; Calculate macro line and offset values ; Load offset value from offset table ; If this is NOT a screen hole ; Load macro line value from macro table ; Compute the actual screen address ; Lookup the character/attribute values ; Store the character to the screen ; Endif this is a screen hole ; Restore the required registers ; Else this is a graphics mode ; If this is low resolution graphics mode page 2 ; Save the required registers ; Save the graphics byte index value ; Set base text video address ; Calculate macro line and offset values ; Load offset value from offset table ; If this is NOT a screen hole ; Load macro line value from macro table ; Compute the actual screen address ; Lookup the graphics mapping value ; Force character code to a half block ; Store the character to the screen ; Endif this is a screen hole ; Restore the required registers ; Endif for mode value ; Return to the caller ; ; Registers on Entry: ; ; AL - Memory value ; DS:DI - 65C02 Effective address ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; DI - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Text_2 Proc Near ; Low res/text page 2 write procedure mov ds:[di],al ; Write the memory location test cs:[Video_Flag],VIDEO_MODE+PAGE_INV jnz Low_Check_2 ; Jump if NOT text mode page 2 Save bx ; Save the required registers xor ah,ah ; Convert character to full word shl ax,1 ; Convert character to table index mov bp,ax ; Save character table index in BP mov ax,di ; Get the effective memory address sub ah,TEXT_PAGE_2 ; Subtract off the starting value shl ax,1 ; Move macro number into AH register xor bh,bh ; Setup to index through video tables mov bl,al ; Convert offset into table index mov di,cs:[bx+Text_Address] ; Get the text offset table value inc di ; Increment for screen hole check js Text_2_Hole ; Jump if this is a screen hole mov bl,ah ; Get macro number into BL register shl bx,1 ; Convert macro number into table index add di,cs:[bx+Macro_Table] ; Compute the actual screen address mov ax,cs:[bp+Char_Table] ; Lookup the correct character value stosw ; Store character value onto screen Text_2_Hole: Restore bx ; Restore the required registers Text_Done_2: ret ; Return to the caller Low_Check_2: test cs:[Video_Flag],RESOLUTION+PAGE_INV jnz Low_Done_2 ; Jump if NOT low resolution page 2 Save bx ; Save the required registers mov ah,al ; Move graphics byte to AH register mov bp,ax ; Save graphices byte value in BP mov ax,di ; Get the effective memory address sub ah,TEXT_PAGE_2 ; Subtract off the starting value shl ax,1 ; Move macro number in AH register xor bh,bh ; Setup to index through video tables mov bl,al ; Convert offset into table index mov di,cs:[bx+Text_Address] ; Get the text offset table value inc di ; Increment for screen hole check js Low_2_Hole ; Jump if this is a screen hole mov bl,ah ; Get macro number into BL register shl bx,1 ; Convert macro number into table index add di,cs:[bx+Macro_Table] ; Compute the actual screen offset mov ax,bp ; Restore the graphics byte value mov al,BLOCK_CHAR ; Force character to block character stosw ; Store graphics value onto screen Low_2_Hole: Restore bx ; Restore the required registers Low_Done_2: ret ; Return to the caller CGA_Text_2 Endp ; End of the CGA_Text_2 procedure Subttl CGA_Graph_1 High Resolution Graphics Page 1 Write Page + ;****************************************************************************** ; ; CGA_Graph_1(Effective_Address, Value) ; ; Write the memory location value (Byte) ; If this is a graphics mode and page 1 ; Save the required registers ; Save the bit value table index value ; Calculate macro/slice and offset values ; Load offset value from offset table ; If this is NOT a screen hole ; Load macro/slice value from macro/slice table ; Compute the actual screen address ; Lookup the reverse bit value ; Lookup the expanded bit value ; Get the word/byte shift count values ; Get the word mask value ; Shift the word mask into position ; Shift the expanded bits into position ; Update the screen word value ; If the byte shift count is NOT zero ; Get the byte mask value ; Shift byte mask into position ; Shift expanded bits into position ; Update the screen byte value ; Endif ; Endif this is a screen hole ; Restore the required registers ; Endif this is NOT a graphics mode ; Return to the caller ; ; Registers on Entry: ; ; AL - Memory value ; DS:DI - 65C02 Effective address ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; DI - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Graph_1 Proc Near ; High res page 1 write procedure mov ds:[di],al ; Write the memory location test cs:[Video_Flag],VIDEO_INV+PAGE_NUMBER+RES_INV jnz Graph_Done_1 ; Jump if NOT high res. mode page 1 Save bx,cx,dx,si ; Save the required registers and ax,COLOR_MASK ; Mask off all but the color bits mov bp,ax ; Save bit value table index in BP mov ax,di ; Get the effective memory address and di,ADDRESS_MASK ; Mask all but required address bits sub ah,GRAPH_PAGE_1 ; Subtract off the starting value shl ax,1 ; Move macro/slice number to AH register xor bh,bh ; Setup to index through video tables mov bl,al ; Convert offset into table index mov si,cs:[bx+CGA_Address] ; Get the graphics offset table value inc si ; Increment for screen hole check js Graph_Exit_1 ; Jump if this is a screen hole mov bl,ah ; Get macro/slice number to BL register shl bx,1 ; Convert macro/slice into table index add si,cs:[bx+CGA_Slice] ; Compute the actual screen address mov ch,cs:[di+CGA_Shift] ; Get the word/byte shift values mov bl,cs:[bp+Reverse_Table]; Lookup the reverse bit value shl di,1 ; Convert address into table index add bx,cs:[di+Column_Table] ; Compute the actual table entry address mov dx,Word Ptr cs:[bx] ; Get the expanded bit value (14 Bits) mov bx,dx ; Get a copy of expanded bit value mov ax,WORD_MASK ; Get the word mask value xor cl,cl ; Setup for word shift count rol cx,4 ; Shift word shift count into CL shr ax,cl ; Shift mask value into position shr bx,cl ; Shift data value into position not ax ; Invert the mask polarity xchg al,ah ; Put mask bytes into the correct order xchg bl,bh ; Put data bytes into the correct order and ax,Word Ptr es:[si] ; Mask off all but desired bits or ax,bx ; Logically OR in the new data bits mov Word Ptr es:[si],ax ; Update the screen data word value xor cl,cl ; Setup for byte shift count rol cx,4 ; Shift byte shift count into CL or cl,cl ; Check for byte value required jz Graph_Exit_1 ; Jump if byte value NOT required mov al,BYTE_MASK ; Get the byte mask value shl al,cl ; Shift mask value into position shl dl,cl ; Shift data value into position not al ; Invert the mask polarity and al,Byte Ptr es:[si+BYTE_OFFSET] or al,dl ; Logically OR in the new data bits mov Byte Ptr es:[si+BYTE_OFFSET],al Graph_Exit_1: Restore bx,cx,dx,si ; Restore the required registers Graph_Done_1: ret ; Return to the caller CGA_Graph_1 Endp ; End of the CGA_Graph_1 procedure Subttl CGA_Graph_2 High Resolution Graphics Page 2 Write Page + ;****************************************************************************** ; ; CGA_Graph_2(Effective_Address, Value) ; ; Write the memory location value (Byte) ; If this is a graphics mode and page 2 ; Save the required registers ; Save the bit value table index value ; Calculate macro/slice and offset values ; Load offset value from offset table ; If this is NOT a screen hole ; Load macro/slice value from macro/slice table ; Compute the actual screen address ; Lookup the reverse bit value ; Lookup the expanded bit value ; Get the word/byte shift count values ; Get the word mask value ; Shift the word mask into position ; Shift the expanded bits into position ; Update the screen word value ; If the byte shift count is NOT zero ; Get the byte mask value ; Shift byte mask into position ; Shift expanded bits into position ; Update the screen byte value ; Endif ; Endif this is a screen hole ; Restore the required registers ; Endif this is NOT a graphics mode ; Return to the caller ; ; Registers on Entry: ; ; AL - Memory value ; DS:DI - 65C02 Effective address ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; DI - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Graph_2 Proc Near ; High res page 2 write procedure mov ds:[di],al ; Write the memory location test cs:[Video_Flag],VIDEO_INV+PAGE_INV+RES_INV jnz Graph_Done_2 ; Jump if NOT high res. mode page 2 Save bx,cx,dx,si ; Save the required registers and ax,COLOR_MASK ; Mask off all but the color bits mov bp,ax ; Save bit value table index in BP mov ax,di ; Get the effective memory address and di,ADDRESS_MASK ; Mask all but required address bits sub ah,GRAPH_PAGE_2 ; Subtract off the starting value shl ax,1 ; Move macro/slice number to AH register xor bh,bh ; Setup to index through video tables mov bl,al ; Convert offset into table index mov si,cs:[bx+CGA_Address] ; Get the graphics offset table value inc si ; Increment for screen hole check js Graph_Exit_2 ; Jump if this is a screen hole mov bl,ah ; Get macro/slice number to BL register shl bx,1 ; Convert macro/slice into table index add si,cs:[bx+CGA_Slice] ; Compute the actual screen address mov ch,cs:[di+CGA_Shift] ; Get the word/byte shift values mov bl,cs:[bp+Reverse_Table]; Lookup the reverse bit value shl di,1 ; Convert address into table index add bx,cs:[di+Column_Table] ; Compute the actual table entry address mov dx,Word Ptr cs:[bx] ; Get the expanded bit value (14 Bits) mov bx,dx ; Get a copy of expanded bit value mov ax,WORD_MASK ; Get the word mask value xor cl,cl ; Setup for word shift count rol cx,4 ; Shift word shift count into CL shr ax,cl ; Shift mask value into position shr bx,cl ; Shift data value into position not ax ; Invert the mask polarity xchg al,ah ; Put mask bytes into the correct order xchg bl,bh ; Put data bytes into the correct order and ax,Word Ptr es:[si] ; Mask off all but desired bits or ax,bx ; Logically OR in the new data bits mov Word Ptr es:[si],ax ; Update the screen data word value xor cl,cl ; Setup for byte shift count rol cx,4 ; Shift byte shift count into CL or cl,cl ; Check for byte value required jz Graph_Exit_2 ; Jump if byte value NOT required mov al,BYTE_MASK ; Get the byte mask value shl al,cl ; Shift mask value into position shl dl,cl ; Shift data value into position not al ; Invert the mask polarity and al,Byte Ptr es:[si+BYTE_OFFSET] or al,dl ; Logically OR in the new data bits mov Byte Ptr es:[si+BYTE_OFFSET],al Graph_Exit_2: Restore bx,cx,dx,si ; Restore the required registers Graph_Done_2: ret ; Return to the caller CGA_Graph_2 Endp ; End of the CGA_Graph_2 procedure Subttl CGA_Text_Off Text Off Routine (Graphics) Page + ;****************************************************************************** ; ; CGA_Text_Off(RAM_Space, Video_Segment) ; ; If currently in a text mode ; Reset the text mode flag bit (Graphics) ; If in high resolution graphics mode ; Set graphics mode 4 (320 x 200) ; Endif ; Call routine to enable intensity (No blink) ; Call routine to restore graphics screen ; Endif ; Return to the caller ; ; Registers on Entry: ; ; DS - 65C02 RAM space ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Text_Off Proc Near ; Text off (Graphics) procedure test cs:[Video_Flag],VIDEO_MODE jnz Text_Off_Done ; Jump if this is NOT a text mode or cs:[Video_Flag],VIDEO_MODE and cs:[Video_Flag],Not VIDEO_INV test cs:[Video_Flag],RESOLUTION jz Do_Graphic ; Jump if low resolution graphics mov ah,SET_MODE ; Get set mode video sub-function code mov al,GRAPH_MODE ; Get the 320x200 graphics mode value int VIDEO ; Set video mode to 320x200 graphics Do_Graphic: call Blink_Off ; Call routine to turn blink off call Graphic_Restore ; Call routine to restore graphics Text_Off_Done: ret ; Return to the caller CGA_Text_Off Endp ; End of the CGA_Text_Off procedure Subttl CGA_Text_On Text On Routine (Text) Page + ;****************************************************************************** ; ; CGA_Text_On(RAM_Space, Video_Segment) ; ; If currently in a graphics mode ; Reset the graphics mode flag bit (Text) ; If in high resolution graphics mode ; Set text mode 0 (40x25) ; Call routine to turn off cursor ; Endif ; Call routine to enable blink (No intensity) ; Call routine to restore text screen ; Endif ; Return to the caller ; ; Registers on Entry: ; ; DS - 65C02 RAM space ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Text_On Proc Near ; Text on (Text) procedure test cs:[Video_Flag],VIDEO_MODE jz Text_On_Done ; Jump if this is a text mode and cs:[Video_Flag],Not VIDEO_MODE or cs:[Video_Flag],VIDEO_INV test cs:[Video_Flag],RESOLUTION jz Do_Text ; Jump if low resolution graphics mov ah,SET_MODE ; Get set mode video sub-function code mov al,TEXT_MODE ; Get the 40x25 text mode value int VIDEO ; Set video mode to 40x25 text mode call Cursor_Off ; Call routine to turn cursor off Do_Text: call Blink_On ; Call routine to turn blink on call Text_Restore ; Call routine to restore text Text_On_Done: ret ; Return to the caller CGA_Text_On Endp ; End of the CGA_Text_On procedure Subttl CGA_Mixed_Off Mixed Off Routine (Text/Graphics) Page + ;****************************************************************************** ; ; CGA_Mixed_Off() ; ; If this is mixed mode ; Reset mixed mode flag bit ; If this is a graphics mode ; Call routine to restore graphics screen ; Endif ; Endif this is mixed mode ; Return to the caller ; ; Registers on Entry: ; ; None ; ; Registers on Exit: ; ; AX - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Mixed_Off Proc Near ; Mixed off (Text/Graphics) procedure mov al,cs:[Video_Flag] ; Get the video flag word test al,MIXED_MODE ; Check for mixed mode already selected jz Mixed_On_Done ; Jump if this IS mixed mode already and cs:[Video_Flag],Not MIXED_MODE or cs:[Video_Flag],MIXED_INV test al,VIDEO_MODE ; Check the video mode flag bit jz Mixed_Off_Done ; Jump if this is NOT a graphics mode call Graphic_Restore ; Call routine to restore graphics Mixed_Off_Done: ret ; Return to the caller CGA_Mixed_Off Endp ; End of the CGA_Mixed_Off procedure Subttl CGA_Mixed_On Mixed On Routine (Text & Graphics) Page + ;****************************************************************************** ; ; CGA_Mixed_On() ; ; If this is NOT mixed mode ; Set mixed mode flag bit ; If this is a graphics mode ; Call routine to update mixed screen ; Endif ; Endif this is NOT mixed mode ; Return to the caller ; ; Registers on Entry: ; ; None ; ; Registers on Exit: ; ; AX - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Mixed_On Proc Near ; Mixed on (Text & Graphics) procedure mov al,cs:[Video_Flag] ; Get the video flag word test al,MIXED_MODE ; Check for mixed mode already selected jnz Mixed_On_Done ; Jump if this IS mixed mode already or cs:[Video_Flag],MIXED_MODE and cs:[Video_Flag],Not MIXED_INV test al,VIDEO_MODE ; Check the video mode flag bit jz Mixed_On_Done ; Jump if this is NOT a graphics mode call Mixed_Update ; Call routine to update mixed screen Mixed_On_Done: ret ; Return to the caller CGA_Mixed_On Endp ; End of the CGA_Mixed_On procedure Subttl CGA_Page_1 Select Page 1 Routine Page + ;****************************************************************************** ; ; CGA_Page_1(RAM_Space, Video_Segment) ; ; If this is NOT page 1 ; Reset page number flag bit (Page 1) ; If this is a text mode ; Call routine to restore text screen ; Else this is a graphics mode ; Call routine to restore graphics screen ; Endif ; Endif this is NOT page 1 ; Return to the caller ; ; Registers on Entry: ; ; DS - 65C02 RAM space ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Page_1 Proc Near ; Select video page 1 procedure mov al,cs:[Video_Flag] ; Get the video flag word test al,PAGE_NUMBER ; Check for page 1 already selected jz Page_1_Done ; Jump if this IS page 1 already and cs:[Video_Flag],Not PAGE_NUMBER or cs:[Video_Flag],PAGE_INV test al,VIDEO_MODE ; Check the video mode flag bit jnz Graphics_1 ; Jump if this is a graphics mode call Text_Restore ; Call routine to restore text screen jmp Short Page_1_Done ; Go return to the caller Graphics_1: call Graphic_Restore ; Call routine to restore graphics Page_1_Done: ret ; Return to the caller CGA_Page_1 Endp ; End of the CGA_Page_1 procedure Subttl CGA_Page_2 Select Page 2 Routine Page + ;****************************************************************************** ; ; CGA_Page_2(RAM_Space, Video_Segment) ; ; If this is NOT page 2 ; Set page number flag bit (Page 2) ; If this is a text mode ; Call routine to restore text screen ; Else this is a graphics mode ; Call routine to restore graphics screen ; Endif ; Endif this is NOT page 2 ; Return to the caller ; ; Registers on Entry: ; ; DS - 65C02 RAM space ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Page_2 Proc Near ; Select video page 2 procedure mov al,cs:[Video_Flag] ; Get the video flag word test al,PAGE_NUMBER ; Check for page 2 already selected jnz Page_2_Done ; Jump if this IS page 2 already or cs:[Video_Flag],PAGE_NUMBER and cs:[Video_Flag],Not PAGE_INV test al,VIDEO_MODE ; Check the video mode flag bit jnz Graphics_2 ; Jump if this is a graphics mode call Text_Restore ; Call routine to restore text screen jmp Short Page_2_Done ; Go return to the caller Graphics_2: call Graphic_Restore ; Call routine to restore graphics Page_2_Done: ret ; Return to the caller CGA_Page_2 Endp ; End of the CGA_Page_2 procedure Subttl CGA_Low_Res Select Low Resolution Routine Page + ;****************************************************************************** ; ; CGA_Low_Res() ; ; If this is NOT low resolution mode ; Set low resolution mode flag bit ; If this is a graphics mode ; Set text mode 0 (40x25) ; Call routine to turn off cursor ; Call routine to enable intensity (No blink) ; Call routine to restore graphics ; Endif ; Endif this is NOT low resolution mode ; Return to the caller ; ; Registers on Entry: ; ; None ; ; Registers on Exit: ; ; AX - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Low_Res Proc Near ; Select low resolution procedure mov al,cs:[Video_Flag] ; Get the video flag byte test al,RESOLUTION ; Check for low resolution mode jz Low_Res_Done ; Jump if this IS low resolution and cs:[Video_Flag],Not RESOLUTION or cs:[Video_Flag],RES_INV test al,VIDEO_MODE ; Check the video mode flag bit jz Low_Res_Done ; Jump if this is NOT a graphics mode mov ah,SET_MODE ; Get set mode video sub-function code mov al,TEXT_MODE ; Get the 40x25 text mode value int VIDEO ; Set video mode to 40x25 text mode call Cursor_Off ; Call routine to turn cursor off call Blink_Off ; Call routine to turn blink off call Graphic_Restore ; Call routine to restore graphics Low_Res_Done: ret ; Return to the caller CGA_Low_Res Endp ; End of the CGA_Low_Res procedure Subttl CGA_High_Res Select High Resolution Routine Page + ;****************************************************************************** ; ; CGA_High_Res() ; ; If this is NOT high resolution mode ; Set high resolution mode flag bit ; If this is a graphics mode ; Set graphics mode 4 (320 x 200) ; Call routine to restore graphics ; Endif ; Endif this is NOT high resolution mode ; Return to the caller ; ; Registers on Entry: ; ; None ; ; Registers on Exit: ; ; AX - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_High_Res Proc Near ; Select high resolution procedure mov al,cs:[Video_Flag] ; Get the video flag byte test al,RESOLUTION ; Check for high resolution mode jnz High_Res_Done ; Jump if this IS high resolution or cs:[Video_Flag],RESOLUTION and cs:[Video_Flag],Not RES_INV test al,VIDEO_MODE ; Check the video mode flag bit jz High_Res_Done ; Jump if this is NOT a graphics mode mov ah,SET_MODE ; Get set mode video sub-function code mov al,GRAPH_MODE ; Get the 320x200 graphics mode value int VIDEO ; Set video mode to 320x200 graphics call Graphic_Restore ; Call routine to restore graphics High_Res_Done: ret ; Return to the caller CGA_High_Res Endp ; End of the CGA_High_Res procedure Subttl Text_Restore Restore Text Screen Routine Page + ;****************************************************************************** ; ; Text_Restore(RAM_Space, Video_Segment) ; ; Save the required registers ; Set source index to page 1 memory (0400h) ; If page 2 is selected ; Set source index to page 2 memory (0800h) ; Endif ; Set destination index to video memory (BASE_ADDRESS) ; Call routine to restore the text memory ; Setup base address to video memory (BASE_ADDRESS) ; Call routine to set base video address ; Restore the required registers ; Return to the caller ; ; Registers on Entry: ; ; DS - 65C02 RAM space ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address Text_Restore Proc Near ; Restore text screen procedure Save bx,cx,dx,si,di ; Save the required registers mov si,TEXT_ADDRESS_1 ; Setup source index for page 1 test cs:[Video_Flag],PAGE_NUMBER jz Do_Restore ; Jump if this really is page 1 mov si,TEXT_ADDRESS_2 ; Setup base address for page 2 Do_Restore: mov di,BASE_ADDRESS ; Setup destination index mov bp,TEXT_MASK ; Setup destination mask value call Restore_Text ; Call routine to restore text page 1 Text_Set: mov bp,BASE_ADDRESS Shr 1 ; Setup base video address call Set_Address ; Call routine to set base address Restore bx,cx,dx,si,di ; Restore the required registers ret ; Return to the caller Text_Restore Endp ; End of the Text_Restore procedure Subttl Restore_Text Restore Text Memory Routine Page + ;****************************************************************************** ; ; Restore_Text(RAM_Space, Video_Segment, Source, Destination, Mask) ; ; Set Macro_Counter to 8 (Restore 8 macro lines [24 rows]) ; While Macro_Counter > 0 ; Set Row_Counter to 3 (Restore 3 rows) ; While Row_Counter > 0 ; Set Character_Counter to 40 (Restore 40 columns) ; While Character_Counter > 0 ; Load a character code from memory ; Lookup the character/attribute value ; Store character/attribute to memory ; Decrement the Character_Counter ; Endwhile for Character_Count ; Increment destination index by ROW_OFFSET (8) ; Mask off all but valid destination address bits ; Endwhile for Row_Counter ; Increment source index by MACRO_OFFSET (8) ; Endwhile for Macro_Counter ; Return to the caller ; ; Registers on Entry: ; ; DS:SI - 65C02 RAM space source index ; ES:DI - Video memory segment destination index ; BP - Destination index address mask ; ; Registers on Exit: ; ; AX-DX - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address Restore_Text Proc Near ; Restore text memory procedure mov dh,MACRO_COUNT ; Setup the macro count (8 = 24 Rows) Macro_Loop: mov dl,ROW_COUNT ; Setup the row count (3 Rows) Save di ; Save the destination index value Row_Loop: mov cx,CHAR_COUNT ; Setup the character count (40 Columns) Char_Loop: lodsb ; Load the character code from memory xor ah,ah ; Convert character code to full word shl ax,1 ; Convert character code to table index mov bx,ax ; Setup to translate the character mov ax,cs:[bx + Char_Table] ; Lookup the correct character value stosw ; Store the character code to memory loop Char_Loop ; Loop till all columns are moved add di,ROW_OFFSET ; Increment destination address value and di,bp ; Mask off all but valid address bits dec dl ; Decrement the row counter value jnz Row_Loop ; Jump if more rows to move add si,MACRO_OFFSET ; Increment source address value Restore di ; Restore the destination index value add di,NEXT_OFFSET ; Increment destination address value dec dh ; Decrement the macro counter value jnz Macro_Loop ; Jump if more macro lines to moves ret ; Return to the caller Restore_Text Endp ; End of the Restore_Text procedure Subttl Graphic_Restore Restore Graphic Screen Routine Page + ;****************************************************************************** ; ; Graphic_Restore(RAM_Space, Video_Segment) ; ; Save the required registers ; If in low resolution graphics mode ; Set source index to page 1 memory (0400h) ; If page 2 is selected ; Set source index to page 2 memory (0800h) ; Endif ; Call routine to restore low resolution memory ; Else in high resolution graphics mode ; Set source index to page 1 memory (2000h) ; If page 2 is selected ; Set source index to page 2 memory (4000h) ; Endif ; Set destination index to video memory (BASE_ADDRESS) ; Call routine to restore high resolution memory ; Endif for type of graphics mode ; Setup base address to video memory (BASE_ADDRESS) ; Call routine to set base video address ; Restore the required registers ; Return to the caller ; ; Registers on Entry: ; ; DS - 65C02 RAM space ; ES - Video memory segment ; ; Registers on Exit: ; ; AX - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address Graphic_Restore Proc Near ; Restore graphic screen procedure Save bx,cx,dx,si,di ; Save the required registers test cs:[Video_Flag],RESOLUTION jz Low_Restore ; Jump if this is low resolution High_Restore: mov si,GRAPH_ADDRESS_1 ; Setup source index for page 1 test cs:[Video_Flag],PAGE_NUMBER jz Do_High ; Jump if this really is page 1 mov si,GRAPH_ADDRESS_2 ; Setup base address for page 2 Do_High: mov di,BASE_ADDRESS ; Setup destination index call Restore_High ; Call routine to restore high res. jmp Short Graphic_Set ; Go setup the base address value Low_Restore: mov si,TEXT_ADDRESS_1 ; Setup source index for page 1 test cs:[Video_Flag],PAGE_NUMBER jz Do_Low ; Jump if this really is page 1 mov si,TEXT_ADDRESS_2 ; Setup base address for page 2 Do_Low: mov di,BASE_ADDRESS ; Setup destination index mov bp,TEXT_MASK ; Setup destination mask value call Restore_Low ; Call routine to restore low page 1 Graphic_Set: mov bp,BASE_ADDRESS ; Get base video address call Set_Address ; Call routine to set base address Graphic_Done: Restore bx,cx,dx,si,di ; Restore the required registers ret ; Return to the caller Graphic_Restore Endp ; End of the Graphic_Restore procedure Subttl Restore_Low Restore Low Resolution Memory Routine Page + ;****************************************************************************** ; ; Restore_Low(RAM_Space, Video_Segment, Source, Destination, Mask) ; ; Set Macro_Counter to 8 (Restore 8 macro lines [24 rows]) ; While Macro_Counter > 0 ; Set Row_Counter to 3 (Restore 3 rows) ; While Row_Counter > 0 ; Set Character_Counter to 40 (Restore 40 columns) ; While Character_Counter > 0 ; Load a graphics byte from memory ; Force character code to half block value ; Store character/attribute to memory ; Decrement the Character_Counter ; Endwhile for Character_Count ; Increment destination index by ROW_OFFSET (8) ; Mask off all but valid destination address bits ; Endwhile for Row_Counter ; Increment source index by MACRO_OFFSET (8) ; Endwhile for Macro_Counter ; Return to the caller ; ; Registers on Entry: ; ; DS:SI - 65C02 RAM space source index ; ES:DI - Video memory segment destination index ; BP - Destination index address mask ; ; Registers on Exit: ; ; AX-DX - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address Restore_Low Proc Near ; Restore low res. memory procedure mov dh,MACRO_COUNT ; Setup the macro count (8 = 24 Rows) Loop_Macro: mov dl,ROW_COUNT ; Setup the row count (3 Rows) Save di ; Save the destination index value Loop_Row: mov cx,CHAR_COUNT ; Setup the character count (40 Columns) Loop_Byte: lodsb ; Load the graphics byte from memory xor ah,ah ; Convert graphics byte to table index mov bx,ax ; Setup to translate the color mov ah,cs:[bx + Map_Table] ; Lookup the correct color value mov al,BLOCK_CHAR ; Force block character code value stosw ; Store the character code to memory loop Loop_Byte ; Loop till all columns are moved add di,ROW_OFFSET ; Increment destination address value and di,bp ; Mask off all but valid address bits dec dl ; Decrement the row counter value jnz Loop_Row ; Jump if more rows to move add si,MACRO_OFFSET ; Increment source address value Restore di ; Restore the destination index value add di,NEXT_OFFSET ; Increment destination address value dec dh ; Decrement the macro counter value jnz Loop_Macro ; Jump if more macro lines to moves ret ; Return to the caller Restore_Low Endp ; End of the Restore_Low procedure Subttl Restore_High Restore High Resolution Memory Routine Page + ;****************************************************************************** ; ; Restore_High(RAM_Space, Video_Segment, Source, Destination) ; ; Set Slice_Counter to 8 (Restore 8 slices [192 lines]) ; While Slice_Counter > 0 ; Set Macro_Counter to 8 (Restore 8 macro lines [24 rows]) ; While Macro_Counter > 0 ; Set Row_Counter to 3 (Restore 3 rows) ; While Row_Counter > 0 ; Set Byte_Counter to 10 (40 Bytes) ; While Byte_Counter > 0 ; Get next graphics byte ; Reverse the data bits ; Expand data bits for even column ; Save the first 8 expanded bits ; Get next graphics byte ; Reverse the data bits ; Expand data bits for odd column ; Combine last 6 bits with next 2 ; Save the next 16 expanded bits ; Get next graphics byte ; Reverse the data bits ; Expand data bits for even column ; Combine last 4 bits with next 4 ; Save the next 16 expanded bits ; Get next graphics byte ; Reverse the data bits ; Expand data bits for odd column ; Combine last 2 bits with next 14 ; Save the last 16 expanded bits ; Endwhile for Byte_Count ; Increment destination index by NEXT_ROW (2490) ; Endwhile for Row_Counter ; Increment source index by NEXT_MACRO (320) ; Endwhile for Macro_Counter ; Toggle destination for odd/even scan line ; If moving to an even scan line ; Increment destination index by NEXT_OFFSET (80) ; Endif ; Endwhile for Slice_Counter ; Return to the caller ; ; Registers on Entry: ; ; DS:SI - 65C02 RAM space source index ; ES:DI - Video memory segment destination index ; ; Registers on Exit: ; ; AX-DX - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address Restore_High Proc Near ; Restore high res. memory procedure mov ch,SLICE_COUNT ; Setup the slice count (8 = 192 Lines) Slice_Next: mov dh,MACRO_COUNT ; Setup the macro count (8 = 24 Rows) Save di ; Save the destination index value Macro_Next: mov dl,ROW_COUNT ; Setup the row count (3 Rows) Save di ; Save the destination index value Row_Next: mov cl,BYTE_COUNT ; Setup graphics count (10 = 40 Bytes) Byte_Next: lodsb ; Get the next graphics data byte mov bl,al ; Move data byte into BL register and bx,COLOR_MASK ; Mask off all but the color bits mov bl,cs:[bx+Reverse_Table]; Reverse the graphics data bits mov bx,cs:[bx+Even_Table] ; Expand data bits for an even column mov al,bh ; Get the first 8 expanded bits stosb ; Store data bits to screen memory mov ah,bl ; Save the last 6 expanded bits lodsb ; Get the next graphics data byte mov bl,al ; Move data byte into BL register and bx,COLOR_MASK ; Mask off all but the color bits mov bl,cs:[bx+Reverse_Table]; Reverse the graphics data bits mov bx,cs:[bx+Odd_Table] ; Expand data bits for an odd column mov al,bh ; Get the first 8 expanded bits shr al,6 ; Save only the first 2 expanded bits or al,ah ; Logically OR with other 6 bits shl bx,2 ; Shift out first 2 expanded bits mov ah,bh ; Move next 8 expanded bits into AH stosw ; Store data bits to screen memory mov ah,bl ; Save the last 4 expanded bits lodsb ; Get the next graphics data byte mov bl,al ; Move data byte into BL register and bx,COLOR_MASK ; Mask off all but the color bits mov bl,cs:[bx+Reverse_Table]; Reverse the graphics data bits mov bx,cs:[bx+Even_Table] ; Expand data bits for an even column mov al,bh ; Get the first 8 expanded bits shr al,4 ; Save only the first 4 expanded bits or al,ah ; Logically OR with other 4 bits shl bx,4 ; Shift out first 4 expanded bits mov ah,bh ; Move next 8 expanded bits into AH stosw ; Store data bits to screen memory mov ah,bl ; Save the last 2 expanded bits lodsb ; Get the next graphics data byte mov bl,al ; Move data byte into BL register and bx,COLOR_MASK ; Mask off all but the color bits mov bl,cs:[bx+Reverse_Table]; Reverse the graphics data bits mov bx,cs:[bx+Odd_Table] ; Expand data bits for an odd column shr bx,2 ; Shift data bits into position mov al,bh ; Move first 6 expanded bits into AL or al,ah ; Logically OR with other 2 bits mov ah,bl ; Move next 8 expanded bits into AH stosw ; Store data bits to screen memory dec cl ; Decrement the graphics byte count jnz Byte_Next ; Jump if more bytes to move add di,NEXT_ROW ; Increment to the next graphics row dec dl ; Decrement the row counter jnz Row_Next ; Jump if more rows to move add si,MACRO_OFFSET ; Increment source address value Restore di ; Restore the destination index value add di,NEXT_MACRO ; Increment to the next macro line dec dh ; Decrement the macro counter value jz Macro_Done ; Jump if all macro lines are moved jmp Macro_Next ; Go process more macro lines Macro_Done: Restore di ; Restore the destination index value xor di,LINE_MASK ; Adjust for the odd scan line offset test di,LINE_MASK ; Check for moving to an even scan line jnz Skip_Inc ; Jump if NOT moving to an even line add di,NEXT_OFFSET ; Adjust for moving to an even scan line Skip_Inc: dec ch ; Decrement the slice counter value jz Restore_Done ; Jump if restore is complete jmp Slice_Next ; Go process more slice sets Restore_Done: ret ; Return to the caller Restore_High Endp ; End of the Restore_High procedure Subttl Mixed_Update Mixed Mode Update Routine Page + ;****************************************************************************** ; ; Mixed_Update() ; ; ; Return to the caller ; ; Registers on Entry: ; ; None ; ; Registers on Exit: ; ; None ; ;****************************************************************************** Even ; Force procedure to even address Mixed_Update Proc Near ; Mixed screen update procedure ret ; Return to the caller Mixed_Update Endp ; End of the Mixed_Update procedure Subttl CGA_Restore Restore Screen Routine Page + ;****************************************************************************** ; ; CGA_Restore(Video_Segment) ; ; If this is text mode ; Set text mode 0 (40x25) ; Call routine to turn off cursor ; Call routine to enable blink (No intensity) ; Call the text restore routine ; Else this is a graphics mode ; If this is high resolution graphics ; Set graphics mode 4 (320 x 200) ; Else this is low resolution graphics ; Set text mode 0 (40x25) ; Call routine to turn off cursor ; Call routine to enable intensity (No blink) ; Endif for graphics resolution ; Call the graphics restore routine ; Endif for video mode ; Return to the caller ; ; Registers on Entry: ; ; ES - Video segment ; ; Registers on Exit: ; ; AX - Destroyed ; BP - Destroyed ; ;****************************************************************************** Even ; Force procedure to even address CGA_Restore Proc Near ; Restore screen procedure test cs:[Video_Flag],VIDEO_MODE jnz Mode_Graphics ; Jump if this is a graphics mode Mode_Text: mov ah,SET_MODE ; Get set mode video sub-function code mov al,TEXT_MODE ; Get the 40x25 text mode value int VIDEO ; Set video mode to 40x25 text mode call Cursor_Off ; Call routine to turn cursor off call Blink_On ; Call routine to turn blink on call Text_Restore ; Call routine to restore text screen jmp Short CGA_Done ; Go return to the caller Mode_Graphics: test cs:[Video_Flag],RESOLUTION jnz CGA_High CGA_Low: mov ah,SET_MODE ; Get set mode video sub-function code mov al,TEXT_MODE ; Get the 40x25 text mode value int VIDEO ; Set video mode to 40x25 text mode call Cursor_Off ; Call routine to turn cursor off call Blink_Off ; Call routine to turn blink off jmp Short Do_CGA ; Go continue the CGA restore CGA_High: mov ah,SET_MODE ; Get set mode video sub-function code mov al,GRAPH_MODE ; Get the 320x200 graphics mode value int VIDEO ; Set video mode to 320x200 graphics Do_CGA: call Graphic_Restore ; Call graphics screen restore routine CGA_Done: ret ; Return to the caller CGA_Restore Endp ; End of the CGA_Restore procedure ;****************************************************************************** ; ; Define the end of the Emulator Code Segment ; ;****************************************************************************** Emulate Ends End ; End of the CGA module