Atari2600

Initial stage Atari 2600 VCS Emulator writen in GO.

Horizontal Movement	Vertical Movement

Controller Input	NTSC Palette

Players and Scoreboard	Scoreboard Colors

Background and Playfield	Playfield Reflection

Emulation status:

Name	Status
CRT NTSC TV Display	OK
Graphics: NTSC Color Palette	OK
Graphics: Background	OK
Graphics: Playfield	OK
Graphics: Scoreboard	OK
Graphics: Scoreboard Player Color	OK
Graphics: Player 0 and Player 1	OK
Graphics: Player Vertical Movement	OK
Graphics: Player Horizontal Movement	OK
Graphics: Player Stretch (NUSIZ0 and NUSIZ1)	OK
Graphics: Player Multiply (NUSIZ0 and NUSIZ1)	OK
Graphics: Player Inverted (REFP0 and REFP1)	OK
Controller Input	OK
Memory page boundary cross detection	OK
CPU Stack	OK
Decimal Mode (BCD)	OK
TIA RO Memory Mirrors (64 bytes)	OK
TIA RW Memory Mirrors (64 bytes)	OK
ROM Memory Mirrors	OK
RAM Memory Mirrors	OK
RIOT RW Memory Mirrors	OK
6502 / 6507 CPU Opcodes	OK

Missing:

• Timers not working well
• Player are not well centralized (horizontal movement)
• Graphics: Improve P0 and P1 scroll (X and Y)
• Graphics: Ball
• Graphics: Missiles
• Scoreboard value increment for both players
• Scoreboard multi digit
• Sound
• Implement ISB "Opcode"
• Return from Black and White mode has incorrect collors
• Implement TIA Collision Detection: a) CXM0P: D6 - M0-P0: Not started D7 - M0-P1: Not started b) CXM1P: D6 - M1-P1: Not started D7 - M1-P0: Not started c) CXP0FB: D6 - P0–BL: Not started D7 - P0–PF: DONE d) CXP1FB: D6 - P1-BL: Not started D7 - P1-PF: DONE e) CXM0FB: D6 - M0-BL: Not started D7 - M0-PF: Not started f) CXM1FB: D6 - M1-BL: Not started D7 - M1-PF: Not started g) CXBLPF: D6 - ----- D7 - BL-PF: Not started h) CXPPMM: D6 - M0–M1: Not started D7 - P0-P1: DONE

Keys:

• Key 6: Console Color switch
• Key 7: Console Game Select switch
• Key 8: Console Reset switch
• Key 9: Enable/Disable Debug
• Key 0: Reset emulation

Documentation:

Opcodes:

https://www.masswerk.at/6502/6502_instruction_set.html

http://www.obelisk.me.uk/6502/reference.html

https://sites.google.com/site/6502asembly/6502-instruction-set/ror

https://www.atariarchives.org/alp/appendix_1.php

https://problemkaputt.de/2k6specs.htm

https://dwheeler.com/6502/oneelkruns/asm1step.html

Addressing:

http://www.obelisk.me.uk/6502/addressing.html#ABY

http://www.emulator101.com/6502-addressing-modes.html

FLAGS:

http://www.obelisk.me.uk/6502/reference.html#CPY

6502:

http://www.6502.org/

NTSC Palette:

http://www.qotile.net/minidig/docs/tia_color.html

Cycles counting:

https://www.randomterrain.com/atari-2600-memories-guide-to-cycle-counting.html

Overflow flag:

http://www.righto.com/2012/12/the-6502-overflow-flag-explained.html

BRK/IRQ/NMI/RESET:

https://www.pagetable.com/?p=410

Memory Map:

https://atariage.com/forums/topic/192418-mirrored-memory/?tab=comments#comment-2439795 https://problemkaputt.de/2k6specs.htm#videohttps://problemkaputt.de/2k6specs.htm#memoryandiomap

Timer

https://atariage.com/forums/topic/133686-please-explain-riot-timmers/

General:

https://cdn.hackaday.io/files/1646277043401568/Atari_2600_Programming_for_Newbies_Revised_Edition.pdf

https://www.atariarchives.org/roots/chapter_6.php

https://pt.slideshare.net/chesterbr/atari-2600programming

https://www.randomterrain.com/atari-2600-memories-tutorial-andrew-davie-01.html#basics

https://dwheeler.com/6502/oneelkruns/asm1step.html

PIXEL:

https://gitter.im/pixellib/Lobby?at=5dbc310c10bd4128a19e5608

Object draw:

https://alienbill.com/2600/playerpalnext.html

Online debugger:

https://8bitworkshop.com/