BPL                     BPL Branch on result plus                     BPL

  Operation:  Branch on N = 0                           N V - B D I Z C
                                                        . . . . . . . .

  +----------------+-----------------------+---------+---------+----------+
  | Addressing Mode| Assembly Language Form| OP CODE |No. Bytes|No. Cycles|
  +----------------+-----------------------+---------+---------+----------+
  |  Relative      |   BPL $FFFF           |   $10   |    2    |    2*    |
  +----------------+-----------------------+---------+---------+----------+
  * Add 1 if branch occurs to same page.
  * Add 2 if branch occurs to different page (see explanation).

What it does: Branches up to 127 bytes forward or 128 bytes backward from its own address if the N flag is clear. In effect, it branches if the seventh bit is clear in the most recent event, as in: LDA #12 or LDA #127. These actions would clear the N flag, signifying that a plus number (or zero) is present in signed arithmetic mode.

Major uses: For testing the results of LDA or ADC or other operations which affect the negative (N) flag. IF-THEN or ON-GOTO type structures in ML can involve the BCC test. It is the opposite of the BMI instruction. BPL can be used for tests of "unshifted" ASCII characters and other bytes which have the seventh bit off and so are lower than 128 (0XXXXXXX).