Port 是 Pin 的集合。由 Port 讀入資料，其中的 bit 代表 Pin 腳。
  * [[http://www3.nd.edu/~lemmon/courses/ee224/web-manual/web-manual/lab3a/node4.html|What is an input/output port?]]
    * 較符合目前定義  
  * [[http://electronics.stackexchange.com/questions/67280/difference-between-reading-port-and-pin|Difference between reading PORT and PIN]]

  * [[http://hackaday.com/2011/11/30/building-a-computer-around-a-6502-processor/|Building a computer around a 6502 processor]]
  * [[http://www.dwheeler.com/6502/oneelkruns/asm1step.html|Assembly In One Step]]
  * [[http://read.pudn.com/downloads122/ebook/520910/X6502.pdf|圖解6502 指令集]]
  * [[http://www.6502.org/|6502.org]]
  * [[http://www.hpmuseum.org/cgi-sys/cgiwrap/hpmuseum/archv013.cgi?read=36186|have info on new CPU in HP12C Platinum...]]
  * [[http://www.pagetable.com/?p=517|Reverse Engineering the MOS 6502 CPU [video]]]
===== 外部連結 =====
  * 6502 軟體、硬體及應用 - 陳金追 松崗
  * [[http://nicotine.knight.blog.163.com/blog/static/26926112200810994132440/?suggestedreading&wumii|6502汇编语言程序设计(1版)]]
  * [[http://nicotine.knight.blog.163.com/blog/static/2692611220089705423961/|6502汇编语言程序设计(2版)之前言]]
  * [[http://wilsonminesco.com/6502primer/index.html|6502 PRIMER: Building your own 6502 computer]]
  * [[http://homepage.ntlworld.com/cyborgsystems/CS_Main/6502/6502.htm|Rockwell 6502 Programmers Reference]]
  * [[http://www.randomterrain.com/atari-2600-memories-tutorial-andrew-davie-01.html|Atari 2600 Programming Tutorial]]
  * [[http://www.atariarchives.org/alp/cover.php|ASSEMBLY LANGUAGE PROGRAMMING FOR THE ATARI COMPUTERS]]
  * [[http://www.obelisk.demon.co.uk/index.html|6502 Assembly Language Programming]]
  * [[http://6502.org/|6502.org]]