;********************************************************************* ;* Here contains 68K assembler source code to convert color byte * ;* information into data that is suitable for a system that * ;* displays color in a multiple plane configuration. This code * ;* assumes each plane is offset by 16 bits (2 bytes). * ;* Available Functions: * ;* * ;* int byte2raw8(char *color_data, char *buffer); 256 color * ;* int byte2raw4(char *color_data, char *buffer); 16 color * ;* int byte2raw2(char *color_data, char *buffer); 4 color * ;* int byte2raw1(char *color_data, char *buffer); 2 color * ;* Return value is the number of bytes written to the buffer. * export byte2raw8 export byte2raw4 export byte2raw2 export byte2raw1 text ;********************************************************************* ;* This will convert byte color into 8 plane pixel color. * ;* Input 16 bytes of color information. * ;* Output 8 integers suitable for displaying on the ATARI. * ;********************************************************************* ;* Function: ;* int byte2raw8(char *color_data, char *buffer); ;* color_data will be converted and placed into location buffer. ;* color_data = A0. (Must be word aligned) ;* buffer = A1. (Must be word aligned) byte2raw8: movem.l D1-D7/A0-A2,-(A7) ; Save used registers. moveq.l #0,D0 ; Now zero them out. moveq.l #0,D1 ; Pixel color store here moveq.l #0,D2 ; in registers D0-D3. moveq.l #0,D3 move.l #$1, D5 ; Set up 'OR' mask. move.l D5,D6 swap D6 adda.l #12,A0 ; Start at end of data. ; In order to plot the data in the correct order. We need ; to reverse the order of the 16 bytes of data. move.l (A0),D4 ; Get the last 4 bytes ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 move #3,D7 ; Loop 4 times (4 bytes). .loop1: lsl.l #1,D4 ; Bit was set? bcc .b12 ; Branch if not. or.l D5,D3 ; Set pixel on plane 7 .b12: lsl.l #1,D4 bcc .b13 or.l D6,D3 ; Plane 6 .b13: lsl.l #1,D4 bcc .b14 or.l D5,D2 ; Plane 5 .b14: lsl.l #1,D4 bcc .b15 or.l D6,D2 ; Plane 4 .b15: lsl.l #1,D4 bcc .b16 or.l D5,D1 ; Plane 3 .b16: lsl.l #1,D4 bcc .b17 or.l D6,D1 ; Plane 2 .b17: lsl.l #1,D4 bcc .b18 or.l D5,D0 ; Plane 1 .b18: lsl.l #1,D4 bcc .b19 or.l D6,D0 ; Plane 0 .b19: lsl.l D5 ; Shift odd and even plane lsl.l D6 ; 'OR' mask. dbf D7,.loop1 ; Branch if data still available. suba.l #4,A0 ; Adjust data pointer to left move.l (A0),D4 ; and get the 3rd 4 byte group. ror.w #8,D4 ; Convert long word into Intel swap D4 ; format. ror.w #8,D4 move #3,D7 ; Set up loop counter. .loop2: lsl.l #1,D4 bcc .b22 or.l D5,D3 ; Plane 7 .b22: lsl.l #1,D4 bcc .b23 or.l D6,D3 ; Plane 6 .b23: lsl.l #1,D4 bcc .b24 or.l D5,D2 ; Plane 5 .b24: lsl.l #1,D4 bcc .b25 or.l D6,D2 ; Plane 4 .b25: lsl.l #1,D4 bcc .b26 or.l D5,D1 ; Plane 3 .b26: lsl.l #1,D4 bcc .b27 or.l D6,D1 ; Plane 2 .b27: lsl.l #1,D4 bcc .b28 or.l D5,D0 ; Plane 1 .b28: lsl.l #1,D4 bcc .b29 or.l D6,D0 ; Plane 0 .b29: lsl.l D5 lsl.l D6 dbf D7,.loop2 suba.l #4,A0 ; Adjust data pointer left and move.l (A0),D4 ; get the 2nd 4 byte group. ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 move #3,D7 ; Set up loop counter. .loop3: lsl.l #1,D4 bcc .b32 or.l D5,D3 ; Plane 7 .b32: lsl.l #1,D4 bcc .b33 or.l D6,D3 ; Plane 6 .b33: lsl.l #1,D4 bcc .b34 or.l D5,D2 ; Plane 5 .b34: lsl.l #1,D4 bcc .b35 or.l D6,D2 ; Plane 4 .b35: lsl.l #1,D4 bcc .b36 or.l D5,D1 ; Plane 3 .b36: lsl.l #1,D4 bcc .b37 or.l D6,D1 ; Plane 2 .b37: lsl.l #1,D4 bcc .b38 or.l D5,D0 ; Plane 1 .b38: lsl.l #1,D4 bcc .b39 or.l D6,D0 ; Plane 0 .b39: lsl.l D5 lsl.l D6 dbf D7,.loop3 suba.l #4,A0 ; Adjust data pointer left and move.l (A0),D4 ; get the first 4 bytes. ror.w #8,D4 ; Shift data to intel format. swap D4 ror.w #8,D4 move #3,D7 ; Loop 4 times. .loop4: lsl.l #1,D4 bcc .b42 or.l D5,D3 ; Plane 7 .b42: lsl.l #1,D4 bcc .b43 or.l D6,D3 ; Plane 6 .b43: lsl.l #1,D4 bcc .b44 or.l D5,D2 ; Plane 5 .b44: lsl.l #1,D4 bcc .b45 or.l D6,D2 ; Plane 4 .b45: lsl.l #1,D4 bcc .b46 or.l D5,D1 ; Plane 3 .b46: lsl.l #1,D4 bcc .b47 or.l D6,D1 ; Plane 2 .b47: lsl.l #1,D4 bcc .b48 or.l D5,D0 ; Plane 1 .b48: lsl.l #1,D4 bcc .b49 or.l D6,D0 ; Plane 0 .b49: lsl.l D5 lsl.l D6 dbf D7,.loop4 movem.l D0-D3,(A1) ; Now move the data into ; buffer. movem.l (A7)+,D1-D7/A0-A2 ; Restore used registers. move.l #16,D0 ; Return number of bytes written. rts ; Return to calling function. ;********************************************************************* ;* This will convert byte color into 4 plane pixel color. * ;* Input 16 bytes of color information. * ;* Output 4 integers suitable for displaying on the ATARI. * ;********************************************************************* ;* Function: ;* int byte2raw4(char *color_data, char *buffer); ;* color_data will be converted and placed into location buffer. ;* color_data = A0. (Must be word aligned) ;* buffer = A1. (Must be word aligned) byte2raw4: movem.l D2-D7/A0-A2,-(A7) ; Save used registers. moveq.l #0,D2 ; in registers D0-D3. moveq.l #0,D3 move.l #$1, D5 ; Set up 'OR' mask. move.l D5,D6 swap D6 adda.l #12,A0 ; Start at end of data. ; In order to plot the data in the correct order. We need ; to reverse the order of the 16 bytes of data. move.l (A0),D4 ; Get the last 4 bytes ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 move #3,D7 ; Loop 4 times (4 bytes). .loop1: lsl.l #4,D4 ; First four bits unused. lsl.l #1,D4 ; Bit was set? bcc .b12 ; Branch if not. or.l D5,D3 ; Set pixel on plane 3 .b12: lsl.l #1,D4 bcc .b13 or.l D6,D3 ; Plane 2 .b13: lsl.l #1,D4 bcc .b14 or.l D5,D2 ; Plane 1 .b14: lsl.l #1,D4 bcc .b15 or.l D6,D2 ; Plane 0 .b15: lsl.l D5 ; Shift odd and even plane lsl.l D6 ; 'OR' mask. dbf D7,.loop1 ; Branch if data still available. suba.l #4,A0 ; Adjust data pointer to left move.l (A0),D4 ; and get the 3rd 4 byte group. ror.w #8,D4 ; Convert long word into Intel swap D4 ; format. ror.w #8,D4 move #3,D7 ; Set up loop counter. .loop2: lsl.l #4,D4 ; First 4 bits unused. lsl.l #1,D4 bcc .b22 or.l D5,D3 ; Plane 3 .b22: lsl.l #1,D4 bcc .b23 or.l D6,D3 ; Plane 2 .b23: lsl.l #1,D4 bcc .b24 or.l D5,D2 ; Plane 1 .b24: lsl.l #1,D4 bcc .b25 or.l D6,D2 ; Plane 0 .b25: lsl.l D5 lsl.l D6 dbf D7,.loop2 suba.l #4,A0 ; Adjust data pointer left and move.l (A0),D4 ; get the 2nd 4 byte group. ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 move #3,D7 ; Set up loop counter. .loop3: lsl.l #4,D4 ; First 4 bits unused. lsl.l #1,D4 bcc .b32 or.l D5,D3 ; Plane 3 .b32: lsl.l #1,D4 bcc .b33 or.l D6,D3 ; Plane 2 .b33: lsl.l #1,D4 bcc .b34 or.l D5,D2 ; Plane 1 .b34: lsl.l #1,D4 bcc .b35 or.l D6,D2 ; Plane 0 .b35: lsl.l D5 lsl.l D6 dbf D7,.loop3 suba.l #4,A0 ; Adjust data pointer left and move.l (A0),D4 ; get the first 4 bytes. ror.w #8,D4 ; Shift data to intel format. swap D4 ror.w #8,D4 move #3,D7 ; Loop 4 times. .loop4: lsl.l #4,D4 ; First 4 bits unused. lsl.l #1,D4 bcc .b42 or.l D5,D3 ; Plane 3 .b42: lsl.l #1,D4 bcc .b43 or.l D6,D3 ; Plane 2 .b43: lsl.l #1,D4 bcc .b44 or.l D5,D2 ; Plane 1 .b44: lsl.l #1,D4 bcc .b45 or.l D6,D2 ; Plane 0 .b45: lsl.l D5 lsl.l D6 dbf D7,.loop4 movem.l D2/D3,(A1) ; Now move the data into ; buffer. movem.l (A7)+,D2-D7/A0-A2 ; Restore used registers. move.l #8,D0 ; Number of bytes written. rts ; Return to calling function. ;********************************************************************* ;* This will convert byte color into 2 plane pixel color. * ;* Input 16 bytes of color information. * ;* Output 2 integers suitable for displaying on the ATARI. * ;********************************************************************* ;* Function: ;* int byte2raw2(char *color_data, char *buffer); ;* color_data will be converted and placed into location buffer. ;* color_data = A0. (Must be word aligned) ;* buffer = A1. (Must be word aligned) byte2raw2: movem.l D3-D7/A0-A2,-(A7) ; Save used registers. moveq.l #0,D3 ; in registers D0-D3. move.l #$1, D5 ; Set up 'OR' mask. move.l D5,D6 swap D6 adda.l #12,A0 ; Start at end of data. ; In order to plot the data in the correct order. We need ; to reverse the order of the 16 bytes of data. move.l (A0),D4 ; Get the last 4 bytes ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 move #3,D7 ; Loop 4 times (4 bytes). .loop1: lsl.l #6,D4 ; First four bits unused. lsl.l #1,D4 ; Bit was set? bcc .b12 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b12: lsl.l #1,D4 bcc .b13 or.l D6,D3 ; Plane 0 .b13: lsl.l D5 ; Shift odd and even plane lsl.l D6 ; 'OR' mask. dbf D7,.loop1 ; Branch if data still available. suba.l #4,A0 ; Adjust data pointer to left move.l (A0),D4 ; and get the 3rd 4 byte group. ror.w #8,D4 ; Convert long word into Intel swap D4 ; format. ror.w #8,D4 move #3,D7 ; Set up loop counter. .loop2: lsl.l #6,D4 ; First 6 bits unused. lsl.l #1,D4 bcc .b22 or.l D5,D3 ; Plane 1 .b22: lsl.l #1,D4 bcc .b23 or.l D6,D3 ; Plane 0 .b23: lsl.l D5 lsl.l D6 dbf D7,.loop2 suba.l #4,A0 ; Adjust data pointer left and move.l (A0),D4 ; get the 2nd 4 byte group. ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 move #3,D7 ; Set up loop counter. .loop3: lsl.l #6,D4 ; First 6 bits unused. lsl.l #1,D4 bcc .b32 or.l D5,D3 ; Plane 1 .b32: lsl.l #1,D4 bcc .b33 or.l D6,D3 ; Plane 0 .b33: lsl.l D5 lsl.l D6 dbf D7,.loop3 suba.l #4,A0 ; Adjust data pointer left and move.l (A0),D4 ; get the first 4 bytes. ror.w #8,D4 ; Shift data to intel format. swap D4 ror.w #8,D4 move #3,D7 ; Loop 4 times. .loop4: lsl.l #6,D4 ; First 4 bits unused. lsl.l #1,D4 bcc .b42 or.l D5,D3 ; Plane 3 .b42: lsl.l #1,D4 bcc .b43 or.l D6,D3 ; Plane 2 .b43: lsl.l D5 lsl.l D6 dbf D7,.loop4 move.l D3,(A1) ; Now move the data into ; buffer. movem.l (A7)+,D3-D7/A0-A2 ; Restore used registers. move.l #4,D0 ; Number of bytes written. rts ; Return to calling function. ;********************************************************************* ;* This will convert byte color into 2 plane pixel color. * ;* Input 16 bytes of color information. * ;* Output 1 integers suitable for displaying on the ATARI. * ;********************************************************************* ;* Function: ;* int byte2raw1(char *color_data, char *buffer); ;* color_data will be converted and placed into location buffer. ;* color_data = A0. (Must be word aligned) ;* buffer = A1. (Must be word aligned) byte2raw1: movem.l D3-D7/A0-A2,-(A7) ; Save used registers. moveq.l #0,D3 ; Zero register D3. ; In order to plot the data in the correct order. We need ; to reverse the order of the 16 bytes of data. adda.l #12,A0 ; Start at end of data. move.l (A0),D4 ; Get the last 4 bytes ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 move.l #$1, D5 ; Set up 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b12 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b12: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b13 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b13: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b14 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b14: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b15 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b15: subq.l #4,A0 move.l (A0),D4 ; Get 4 bytes ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b22 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b22: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b23 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b23: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b24 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b24: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b25 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b25: subq.l #4,A0 move.l (A0),D4 ; Get 4 bytes ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b32 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b32: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b33 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b33: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b34 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b34: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b35 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b35: subq.l #4,A0 move.l (A0),D4 ; Get 4 bytes ror.w #8,D4 ; Convert to Intel format. swap D4 ror.w #8,D4 lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b42 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b42: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b43 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b43: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b44 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b44: lsl.l D5 ; Shift 'OR' mask. lsl.l #7,D4 ; First 7 bits unused. lsl.l #1,D4 ; Bit was set? bcc .b45 ; Branch if not. or.l D5,D3 ; Set pixel on plane 1 .b45: move.w D3,(A1) ; Now move the data into ; buffer. movem.l (A7)+,D3-D7/A0-A2 ; Restore used registers. move.l #2,D0 ; Number of bytes written. rts ; Return to calling function. end_loop: bra end_loop ; just in case. end