text editor; = key is backspace / key is shift for capital letters type in .eq to get = character arrow keys to move the cursor its just a basic editor right now and doesnt do much assembly; semi-colons comment out everything after them ; this is a comment and would be ignored by the assembler all 'legal' instructions and addressing modes are supported there are a few directives supported as well, .org to set the address for the following code or data to be placed at. .db / .byte to place 8 bit values directly in memory .dw / .word to place 16 bit values directly in memory (little endian). all of the following are equivalent: .dw $1234 .word $1234 .db $34, $12 .equ (which just places an = sign) to set constant values. dec10 = 10 bin10 = %00000010 hex10 = $10 emulator; the emulator works alot like the one on easy6502 (link in notes and credits). the screen is mapped to memory locations $0200 to $05ff. its 32 by 32 pixels and theyre mapped directly to the 1024 memory locations from $0200 up, starting at the top left, to right, to the second from top left to right, all the way down to the bottom left to right. zero page address $fe is a random value refreshed every frame. zero page address $ff holds the ascii code for the last key pressed. the reset vector at $fffc and $fffd is used to set the program counter when you start a program. and the interrupt vector at $fffe and $ffff is used to set the jump address during a break instruction. therefore, i would recommend doing something like this: .org $0600 ; start writing your code here ; and after your code, .org $fffc .word $0600 the first part just says to place your program at $0600 (which is right where the screen data ends). the last part says where the cpu should go to start (ie, where your program is)
easy6502: http://skilldrick.github.io/easy6502/ an invaluable resource: http://6502.org/users/obelisk/index.html
