Hyunji Jane Lee

What I have learned this week 1. Learning the example code: Place a Graphic on the screen  1-1. Code Learning         define WIDTH        4        ; width of graph        define HEIGHT   4        ; height of graph                        lda                #$25                ; create a pointer at $10                        sta                $10                  ;   which points to where                        lda               #$02             ...

What I have learnt this week 1. How the bitmapped display consists When I look at the notes in a 6502 assembler in a website,  Pages $02 to $ 05 is bitmapped dispaly. The first page is $02 and the last one is $05. Each page has 0 - 255 (00 - ff) pixels. The top left is #$0200 and the top right is #$021f. The bottom left is #$05e0 and bottom right is #$05ff. When I store the pages, I should store the page location in a lower address and the page number in a higher address. For example, If you store  #$00 which is page location in $10 address, you should store page number #$02 in $11 address. 2. Status Register NV-BDIZC (1) N: Negative When you set the value type unsigned value, from 00 to 7f is positive value and 80 to ff is negative value. (2) V: Overflow It can be used when you set the value type unsigned. When the value becomes positive value to negative value or negative value to positive value, it will be flagged. Negative Value to Positive value....