*[https://www.nesdev.org/wiki/CPU_unofficial_opcodes Opcode matrix arrangement]
*[https://www.oxyron.de/html/opcodes.html Oxyron Opcode Matrices]
*[https://archive.org/details/Programming_the_6502_OCR/ Rodney Zak's Programming the 6502]
*[http://www.6502.org/documents/datasheets/synertek/synertek_programming_manual.pdf Synertek SY650x programming manual (250 pages)]
*[http://www.6502.org/documents/datasheets/synertek/synertek_hardware_manual.pdf Synertek SY650x hardware manual (178 pages)]