code: function sra (cpu, n) {
      const r = n & 0x80 | n >> 1;
  
      cpu.f = 0;
      if ((r & 0xff) == 0) cpu.f |= FLAG_Z;
      if ((n & 1) != 0) cpu.f |= FLAG_C;
  
      return r;
  }
docs: SRA n
  
  Description:
  Shift n right into Carry. MSB doesn't change.
  
  Use with:
  n = A, B, C, D, E, H, L, (HL)
  
  Flags affected:
  Z - Set if result is zero.
  N - Reset.
  H - Reset.
  C - Contains old bit 0 data.
  
  Opcodes:
  Instruction    Parameters    Opcode    Cycles
  SRA            A             CB 2F     8
  SRA            B             CB 28     8
  SRA            C             CB 29     8
  SRA            D             CB 2A     8
  SRA            E             CB 2B     8
  SRA            H             CB 2C     8
  SRA            L             CB 2D     8
  SRA            (HL)          CB 2E     16