ROL (thing)

A 6502 instruction that shifts all bits in the A register or a memory location to the left, moving bit 7 into the carry and the old carry into bit 0.

• Function: N << 1 | C => N
• Updates flags: S Z C
• Opcode numbers:

  dp    $26
  impl  $2A  ; affects accumulator
  abs   $2E
  d,x   $36
  a,x   $3E
  

Don't forget to add 2 cycles to modes other than impl, as those modes are read-modify-write.

Similar: ASL | LSR | ROR | INC | DEC
See also: 6502 instructions | 6502 addressing modes