The imagedata pointer of the vsprite structure must be initialized with the address of the first word of the image data array. The image data array must be in Chip memory. It takes two sequential 16-bit words to define each line of a VSprite. This means that the data area containing the VSprite image is always Height x 2 (10 in the example case) words long. A VSprite image is defined just like a real hardware sprite. The combination of bits in corresponding locations in the two data words that define each line select the color for that pixel. The first of the pair of words supplies the low-order bit of the color selector for that pixel; the second word supplies the high-order bit. These binary values select colors as follows: 00 - selects "transparent" 01 - selects the first of three VSprite colors 10 - selects the second VSprite color 11 - selects the third VSprite color In those areas where the combination of bits yields a value of 0, the VSprite is transparent. This means that the playfield, and all Bobs and AnimComps, and any VSprite whose priority is lower than this VSprite will all show through in transparent sections. For example: (&VSprite->ImageData) 1010 0000 0000 0000 (&VSprite->ImageData + 1) 0110 0000 0000 0000 Reading from top to bottom, left to right, the combinations of these two sequential data words form the binary values of 01, 10, 11, and then all 00s. This VSprite's first pixel will be color 1, the next color 2, the third color 3. The rest will be transparent, making this VSprite appear to be three pixels wide. Thus, a three-color image, with some transparent areas, can be formed from a data set like the following sample: Address Binary Data VSprite Image Data ------- ----------- ------------------ mem 1111 1111 1111 1111 Defines top line mem + 1 1111 1111 1111 1111 3333 3333 3333 3333 mem + 2 0011 1100 0011 1100 Defines second line mem + 3 0011 0000 0000 1100 0033 1100 0011 3300 mem + 4 0000 1100 0011 0000 Defines third line mem + 5 0000 1111 1111 0000 0000 3322 2233 0000 mem + 6 0000 0010 0100 0000 Defines fourth line mem + 7 0000 0011 1100 0000 0000 0032 2300 0000 mem + 8 0000 0001 1000 0000 Defines fifth line mem + 9 0000 0001 1000 0000 0000 0003 3000 0000 The vsprite.height for this sample image is 5.