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Machine language - 6502 opcodes

 Assembly language instruction set list

  Code      Operation
  
  ADC       ADd memory to accumulator with Carry
  AND       AND memory with accumulator
  ASL       (Arithmetic) Shift Left one bit
  BCC       Branch on Carry Clear
  BCS       Branch on Carry Set
  BEQ       Branch on result EQual to zero
  BIT       test BITs in accumulator with memory
  BMI       Branch on result MInus (negative)
  BNE       Branch on result Not Equal to zero
  BPL       Branch on result PLus (positive)
  BRK       force Break
  BVC       Branch on oVerflow flag Clear
  BVS       Branch on oVerflow flag Set
  CLC       CLear Carry flag
  CLD       CLear (binary-coded) Decimal mode
  CLI       CLear Interrupt disable flag
  CLV       CLear oVerflow flag
  CMP       CoMPare memory and accumulator
  CPX       ComPare memory and index X
  CPY       ComPare memory and index Y
  DEC       DECrement memory by one
  DEX       DEcrement index X by one
  DEY       DEcrement index Y by one
  EOR       Exclusive OR memory with accumulator
  INC       INCrement memory by one
  INX       INcrement index X by one
  INY       INcrement index Y by one
  JMP       JuMP to new location
  JSR       Jump to new location, Save Return address (Jump to SubRoutine)
  LDA       LoaD Accumulator from memory
  LDX       LoaD index X from memory
  LDY       LoaD index Y from memory
  LSR       (Logical) Shift Right one bit
  NOP       No OPeration
  ORA       OR memory with Accumulator
  PHA       PusH Accumulator on stack
  PHP       PusH Processor status on stack
  PLA       PulL Accumulator from stack
  PLP       PulL Processor status from stack
  ROL       ROtate Left one bit
  ROR       ROtate Right one bit
  RTI       ReTurn from Interrupt
  RTS       ReTurn from Subroutine
  SBC       SuBtract memory and borrow from accumulator (SuBtract with Carry)
  SEC       SEt Carry flag
  SED       SEt (binary-coded) Decimal mode
  SEI       SEt Interrupt disable flag
  STA       STore Accumulator in memory
  STX       STore index X in memory
  STY       STore index Y in memory
  TAX       Transfer Accumulator to index X
  TAY       Transfer Accumulator to index Y
  TSX       Transfer Stack pointer to index X
  TXA       Transfer index X to Accumulator
  TXS       Transfer index X to Stack pointer
  TYA       Transfer index Y to Accumulator
    

 Character codes for assembly language instruction set

Reference card above is taken (I hope with permission) from atariarchives.org!