This example will show how to use the double buffering.

 
     PROCEDURE example ON COCO3
 
         BITMAP ENABLE (160,200,16)
 
         DOUBLE BUFFER ON
         CLS BLACK
         SCREEN SWAP
         CLS BLACK
         SCREEN SWAP
 
         anim := LOAD IMAGES("ponyo2.gif") FRAME SIZE AUTO
 
         DO
             PUT IMAGE anim FRAME frame AT 0, 0
             PUT IMAGE anim FRAME frame AT 32, 0
             PUT IMAGE anim FRAME frame AT 0, 32
             PUT IMAGE anim FRAME frame AT 32, 32
             ADD frame, 1, 0 TO FRAMES(anim)-1
             LOCATE 0, 10
             PEN COLOR(1)
             IF SCREEN PAGE = PAGE A THEN
                 PRINT "PAGE A"
             ELSE
                 PRINT "PAGE  B"
             ENDIF
             WAIT VBL
             SCREEN SWAP
         LOOP
 
     END PROC
 
     example[] ON COCO3
     

• graphics_double_buffer_01.bas

The instructions here refer to compiling the example from the command line. For Microsoft Windows users we suggest using UGBASIC-IDE, which allows you to compile the example with just one click.

In order to compile and run the example, you need to have the Altirra emulator, and in particular that the altirra executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.atari graphics_double_buffer_01.bas -o example.xex
 altirra example.xex
 
 # Windows 
 ugbc.atari.exe graphics_double_buffer_01.bas -o example.xex
 altirra example.xex

In order to compile and run the example, you need to have the Altirra emulator, and in particular that the altirra executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.atarixl graphics_double_buffer_01.bas -o example.xex
 altirra example.xex
 
 # Windows 
 ugbc.atarixl.exe graphics_double_buffer_01.bas -o example.xex
 altirra example.xex

In order to compile and run the example, you need to have the VICE emulator, and in particular that the x64sc executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.c64 graphics_double_buffer_01.bas -o example.prg
 x64sc example.prg
 
 # Windows 
 ugbc.c64.exe graphics_double_buffer_01.bas -o example.prg
 x64sc example.prg

In order to run the example, you need to have the YAPE emulator. In particular that the yape executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.plus4 graphics_double_buffer_01.bas -o example.prg
 yape example.prg
 
 # Windows 
 ugbc.plus4.exe graphics_double_buffer_01.bas -o example.prg
 yape example.prg

In order to run the example, you need to have the VICE emulator. In particular that the xplus4 executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.plus4 graphics_double_buffer_01.bas -o example.prg
 xplus4 example.prg
 
 # Windows 
 ugbc.plus4.exe graphics_double_buffer_01.bas -o example.prg
 xplus4 example.prg

In order to compile and run the example, you need to have the XROAR emulator, and in particular that the xroar executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.d32 graphics_double_buffer_01.bas -o example.bin
 xroar -rompath (your rom path) example.bin
 
 # Windows 
 ugbc.d32.exe graphics_double_buffer_01.bas -o example.bin
 xroar.exe -rompath (your rom path) example.bin

In order to compile and run the example, you need to have the XROAR emulator, and in particular that the xroar executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.d64 graphics_double_buffer_01.bas -o example.bin
 xroar -rompath (your rom path) example.bin
 
 # Windows 
 ugbc.d64.exe graphics_double_buffer_01.bas -o example.bin
 xroar.exe -rompath (your rom path) example.bin

In order to compile and run the example, you need to have the DCMOTO emulator, and in particular that the dcmoto executable is accessible.

Then, type this command on the command line and on the emulator:

 # Linux 
 ugbc.pc128op graphics_double_buffer_01.bas -o example.k7
 dcmoto
 (choose BASIC 128)
 CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
 
 # Windows 
 ugbc.pc128op.exe graphics_double_buffer_01.bas -o example.k7
 dcmoto
 (choose example.k7)
 (choose BASIC 128)
 CLEAR,&H2FFF: LOADM"CASS:",R: EXEC

In order to compile and run the example, you need to have the DCMOTO emulator, and in particular that the dcmoto executable is accessible.

Then, type this command on the command line and on the emulator:

 # Linux 
 ugbc.pc128op graphics_double_buffer_01.bas -o example.k7
 dcmoto
 (choose BASIC 128)
 CLEAR,&H2FFF: LOADM"CASS:",R: EXEC
 
 # Windows 
 ugbc.pc128op.exe graphics_double_buffer_01.bas -o example.k7
 dcmoto
 (choose example.k7)
 (choose BASIC 128)
 CLEAR,&H2FFF: LOADM"CASS:",R: EXEC

In order to compile and run the example, you need to have the VICE emulator, and in particular that the xvic executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.vic20 graphics_double_buffer_01.bas -o example.prg
 xvic --memory 24k example.prg
 
 # Windows 
 ugbc.vic20.exe graphics_double_buffer_01.bas -o example.prg
 xvic --memory 24k example.prg

In order to compile and run the example, you need to have the Speccy emulator, and in particular that the speccy executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.zx graphics_double_buffer_01.bas -o example.tap
 Speccy example.tap
 
 # Windows 
 ugbc.zx.exe graphics_double_buffer_01.bas -o example.tap
 Speccy example.tap

In order to compile and run the example, you need to have the openMsx or the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.msx1 graphics_double_buffer_01.bas -o example.rom
 openmsx -cart example.rom
 
 # Windows 
 ugbc.msx1.exe graphics_double_buffer_01.bas -o example.rom
 openmsx -cart example.rom

 # Linux 
 ugbc.msx1 graphics_double_buffer_01.bas -o example.rom
 bluemsx example.rom
 
 # Windows 
 ugbc.msx1.exe graphics_double_buffer_01.bas -o example.rom
 bluemsx example.rom

In order to compile and run the example, you need to have the openMsx or the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.coleco graphics_double_buffer_01.bas -o example.rom
 openmsx -machine \"COL - ColecoVision\" -cart example.rom
 
 # Windows 
 ugbc.coleco.exe graphics_double_buffer_01.bas -o example.rom
 bluemsx -machine \"COL - ColecoVision\" example.rom

 # Linux 
 ugbc.coleco graphics_double_buffer_01.bas -o example.rom
 bluemsx /machine \"COL - ColecoVision\" /rom1 example.rom
 
 # Windows 
 ugbc.coleco.exe graphics_double_buffer_01.bas -o example.rom
 bluemsx  /machine \"COL - ColecoVision\" /rom1 example.rom

In order to compile and run the example, you need to have the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.sc3000 graphics_double_buffer_01.bas -o example.rom
 bluemsx /machine \"SEGA - SC-3000\" /rom1 example.rom
 
 # Windows 
 ugbc.sc3000.exe graphics_double_buffer_01.bas -o example.rom
 bluemsx  /machine \"SEGA - SC-3000\" /rom1 example.rom

In order to compile and run the example, you need to have the BlueMSX emulator, and in particular that its executable is accessible.

Then, type this command on the command line:

 # Linux 
 ugbc.sg1000 graphics_double_buffer_01.bas -o example.rom
 bluemsx /machine \"SEGA - SG-1000\" /rom1 example.rom
 
 # Windows 
 ugbc.sg1000.exe graphics_double_buffer_01.bas -o example.rom
 bluemsx  /machine \"SEGA - SG-1000\" /rom1 example.rom

If you have found a problem trying to run this example, if you think there is a bug or, more simply, you would like it to be improved, open an issue for this example on GitHub. Thank you!