*** Screen and colour character position addresses ***
First right click on the screen addresses on page-13 to copy and print them out so you can refer to them later.
A `character` can be printed on the screen using `character` position addresses which are from `0400` to `07E7` hex and the `character` colour position addresses to colour the `character` are from `D800` to `DBE7` hex.
Please note from the positions below ,the screen and colour character position addresses from the 2nd to 40th columns the addresses are indicated with the end 2 characters of the address in each square section.Example in row 1 ,column 2 the address is `01` thus the actual address is `0401` and the colour address is `D801`.
In the examples below shows the 1st two characters of the screen and colour position addresses.
1st two characters screen address 1st two characters colour address
04 ================================ D8
05 ================================ D9
06 ================================ DA
07 ================================ DB
Here is how to print a `character` on the screen and colour it:-
Enter the `Monitor` and type
.A C000 JSR$E544 [clear the screen
.A C003 LDA#$00 [load `A` with the value `00` (code number for colour black)]
.A C005 STA$D020 [store the value of `A` into address D020]
.A C008 STA$D021 [ " " " " " " " D021]
.A C00B LDA#$51 [load `A` with value `51` (ball)]
.A C00D STA$05F1 [store the value of `A` into screen address 05F1]
.A C010 LDA#$07 [load `A` with value `07`(code number for yellow)]
.A C012 STA$D9F1 [store the value of `A` into address D9F1
(colour address for screen address 05F1)]
.A C015 JMP$C00B [jump to address C00B to keep the program running]
Please do not enter in the `Monitor` after the commands the `brackets [ ]` and the `information`.The information is only there for reference.
`D020` address is for to colour the `border`(e.g. `00` black) and `D021` address is to colour the `background` (e.g. `00` black).
`51` is the code number for the character `a ball` and the screen character address `05F1` combined with the colour character address `D9F1` is positioned in the `middle` of the screen.
Now clear the screen and type .X and press `return` then press `F3` you are now back in `basic`.Type SYS49152 and press `return` to run the program, as you will see in the `middle` of the screen a `yellow ball`.
To return to `basic` press `Stop/Restore` same time.
