Apple II User Manual

     En        INR       Rn     (Increment)

     Fn        DCR       Rn     (Decrement)

Non-register OPS-

     00        RTN              (Return to 6502 mode)

     01        BR        ea     (Branch always)

     02        BNC       ea     (Branch if No Carry)

     03        BC        ea     (Branch if Carry)

     04        BP        ea     (Branch if Plus)

     05        BM        ea     (Branch if Minus)

     06        BZ        ea     (Branch if Zero)

     07        BNZ       ea     (Branch if NonZero)

     08        BM1       ea     (Branch if Minus 1)

     09        BNM1      ea     (Branch if Not Minus 1)

     0A        BK               (Break)

     0B        RS               (Return from Subroutine)

     0C        BS        ea     (Branch to Subroutine)

     0D                         (Unassigned)

     0E                         (Unassigned)

     0F                         (Unassigned)

Register Instructions:

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SET:

     SET Rn,Constant     [ 1n Low High ]

     The 2-byte constant is loaded into Rn (n=0 to F, Hex) and

     branch conditions set accordingly. The carry is cleared.

     EXAMPLE:

     15 34 A0   SET  R5   $A034     ;R5 now contains $A034

LOAD:

     LD Rn               [ 2n ]

     The ACC (R0) is loaded from Rn and branch conditions set

     according to the data transferred. The carry is cleared and

     contents of Rn are not disturbed.

     EXAMPLE:

     15 34 A0   SET  R5   $A034

     25         LD   R5             ;ACC now contains $A034

STORE:

     ST Rn               [ 3n ]

     The ACC is stored into Rn and branch conditions set according

     to the data transferred. The carry is cleared and the ACC

     contents are not disturbed.