The screen has 2 resolutions. One for `high resolution` which has 320 positions or pixals across and 200 positions or pixals down. The other resolution is `low resolution` which has 40 positions across and 25 positions down (1000 in all). In the `high resolution ` screen, `sprites` ( graphic movable objects) are used. In the `low resolution `screen, ` graphic characters` are used. A `sprite` is made up of 24 pixals across and 21 pixals down (total 504 pixals) and can be made to move about anywhere in the screen. A `graphic character` is made up of 8 pixals across by 8 pixals down (total 64 pixals) and can be printed on the screen anywhere. A `sprite ` and a `graphic character` can be displayed on the screen together.

The Computer Screen

*** Sprite Design ***

Designing a sprite:- Sprite design `robot car`. In the above example a sprite is made up of 504 dots.These are arranged in a 24 dot wide by 21 dot deep grid. You can set up your own grid. Draw a grid on sheet of blank paper that is 24 squares across and 21 squares down. Shade in the squares that are part of your design. Using the `sprite` design above the next step is to convert the graphic design into data the computer can use. Starting with the top row divide the 24 squares across into 3 sections of 8 squares that are part of your design. Above the 1st row write the numbers 8,4,2,1,8,4,2,1 in each section so you have 3 sets (bytes) to get byte value numbers for each row. Each dot on the sprite design corresponds to a bit. In order to design a sprite,you simply make the relevant bit full from the grid. Each line on the grid contains 24 bits (3 bytes). Each sprite takes 63 bytes. Think of the squares that you have shaded in as full bits and the squares that are not shaded in as empty bits. Now look along row 1 of your design and think of each 8 square section as a byte, add the byte 8 bit codes together that are full in the 1st byte ( 08). Do the same with the remainder 2 bytes across and all the 21 rows. Make sure that each section of 8 bits bit codes of the 3 bytes across in row 1 are in hex values . Now convert the remainder 20 rows giving 63 byte values in all. Starting with the 1st row of byte values enter the 1st value at the 1st available address (see Monitor page) e.g. address 3500, the next value in address 3501, the next value in address 3502. Do the same with the remaining values starting at address 3503 till you reach the last value at address 353E. For your next sprite design the next starting address is 3540. Address 353F is made vacant. There should alweays be a vacant address between sprite designs. You can enter the sprite `robot car` data in the computer by entering the `Monitor` (e.g. `Action Replay` after computer is newly switched on press `F1` then press `M` you are now in the `Monitor`) type .M 3500 3540 you will see on screen 8 rows of 8 two character value numbers across.Starting from the 1st row 1st value number type over each one with the value numbers of the `robot car` above which starts with the 1st row of the 1st value number `08` then the 2nd one across(`80`) and then the 3rd one across (`00`) then go on to the 2nd row 1st value number (`0F`) then the 2nd and so on... Press `Return` after you enter every 8th value number. There should be 64 value numbers entered in all (type the last value number in with `00`). Now clear the screen (shift/home) and type in the following program:- .A 4000 LDA#$01 .A 4002 STA$D015 .A 4005 LDA#$D4 .A 4007 STA$07F8 .A 400A LDA#$07 .A 400C STA$D027 .A 400F LDA#$24 .A 4011 STA$D000 .A 4014 LDA#$CD .A 4016 STA$D001 .A 4019 JMP$4000 Clear the screen by pressing `shift/home` then type .X then press `Return` you are now in `basic` type SYS16384 then press `Return` the `robot car` will appear bottom left screen coloured yellow. Press `Stop/Restore` same time to get out of the program. Below is what `Action Replay` monitor looks like when newly entered:-

Designing a `character` :- Character design `key`. A `character` is made up of 64 dots. These are arranged in a 8 dot wide by a 8 dot deep grid. You can set up your own grid. Draw a grid that is 8 squares across and 8 squares down then shade in the squares that makes up your design. Using the above `character` design the next step is to convert the graphic design into data that the computer can use. Above the 1st row write numbers 8,4,2,1,8,4,2,1 to get byte value numbers for each row. Each dot on the `character` corresponds to a bit. In order to design a `character` you simply make the relevent bit full to get byte value numbers from the grid. Each row on the grid contains 8 bits (1 byte). Each `character` on the grid takes up 8 bytes. Think of the squares you have shaded in as full bits and the squares you have not shaded in as empty bits. Now look along row 1 and add the byte 8 bit codes together that are full to make a value number for the 1st byte (`0F`). Make sure the 1st byte 8 bits bit codes are in hex. Do the same with the remainder 7 rows giving 8 value numbers in all. Starting with the 1st row value number enter the value number into the 1st available address (see Monitor page) e.g address 3200 the next value in the address 3201 and so on till you reach address 3207 (8 bytes in all). The next available address for the next `character` is 3208. You will be able to see the character `key` later on.

*** Character Design ***

*** Multicoloured Sprites ***

A multicoloured sprite can have 4 separate colours and the background must be one of them. A colour in a multicolour sprite is always made up of 2 bits in a byte that is using bits 7+6,5+4,3+2 and 1+0. Any colour can use bits 7+6 ,bits 5+4,bits 3+2 and bits 1+0. The 2 colour bits are defined as `00` represents colour 1 (background) `01` " " 2 `10` " " 3 `11` " " 4 So to recall what we have taken in ,a byte of 4 different colours we have bits `00`,`01`, `10` and `11` which can be arranged like as bit 7 is empty ,bit 6 is empty ,bit 5 is empty, bit 4 is full, bit 3 is full, bit 2 is empty, bit 1 is full and bit 0 is full. In the sprite designs below (Manky standing) the left side `Manky` is designed in 4 different colours and the right side the same design but the colours replaced with defined colour bits in the squares. All the squares that has a `1` in it the bit is full and all the squares that has a `zero` in it the bit is empty. In the left design colour brown signifys define bit `01` in the right design " " " " " light red " " " `10` " " " " " " " " " yellow " " " `11` " " " " " " " " " transparent " " " `00` " " " " (background)