User talk:Karatorian/6502 Instruction Set: Difference between revisions

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==Unoffical codes==
Can you also add the stable unofficial codes to this table (perhaps in italics so that you can know the difference)? --[[User:Zzo38|Zzo38]] ([[User talk:Zzo38|talk]]) 19:59, 11 October 2013 (MDT)

Latest revision as of 01:59, 12 October 2013

Existing Versions and Diffs

As far as I know, there are three versions of this document in the wild:

  1. The unattributed original. (I'll call it 1.00, but it's unnumbered.)
  2. Revision 1.02 by _Bnu.
  3. Revision 1.03 by _Gist.

It's implied that there is a 1.01 revision, but I've never seen it.

_Bnu's changes appear to be relatively modest and limited to fixing a few typos (which look rather like OCR errors to me).

--- 6502-100.txt	2013-10-08 22:03:16.000000000 -0400
+++ 6502-102.txt	2013-10-08 22:03:48.000000000 -0400
@@ -1,5 +1,7 @@
 6502 Microprocessor
 
+ Revision 1.02 by _Bnu.
+
  Most of the following information has been taking out of the "Commodore 64
 Programmers Reference Manual" simply because it was available in electronic
 form and there appears to be no difference between this documentation and
@@ -383,7 +385,7 @@
   |  Zero Page     |   ADC Oper            |    65   |    2    |    3     |
   |  Zero Page,X   |   ADC Oper,X          |    75   |    2    |    4     |
   |  Absolute      |   ADC Oper            |    60   |    3    |    4     |
-  |  Absolute,X    |   ADC Oper,X          |    70   |    3    |    4*    |
+  |  Absolute,X    |   ADC Oper,X          |    7D   |    3    |    4*    |
   |  Absolute,Y    |   ADC Oper,Y          |    79   |    3    |    4*    |
   |  (Indirect,X)  |   ADC (Oper,X)        |    61   |    2    |    6     |
   |  (Indirect),Y  |   ADC (Oper),Y        |    71   |    2    |    5*    |
@@ -710,7 +712,7 @@
   |  Zero Page     |   EOR Oper            |    45   |    2    |    3     |
   |  Zero Page,X   |   EOR Oper,X          |    55   |    2    |    4     |
   |  Absolute      |   EOR Oper            |    40   |    3    |    4     |
-  |  Absolute,X    |   EOR Oper,X          |    50   |    3    |    4*    |
+  |  Absolute,X    |   EOR Oper,X          |    5D   |    3    |    4*    |
   |  Absolute,Y    |   EOR Oper,Y          |    59   |    3    |    4*    |
   |  (Indirect,X)  |   EOR (Oper,X)        |    41   |    2    |    6     |
   |  (Indirect),Y  |   EOR (Oper),Y        |    51   |    2    |    5*    |
@@ -871,7 +873,7 @@
   |  Zero Page     |   ORA Oper            |    05   |    2    |    3     |
   |  Zero Page,X   |   ORA Oper,X          |    15   |    2    |    4     |
   |  Absolute      |   ORA Oper            |    0D   |    3    |    4     |
-  |  Absolute,X    |   ORA Oper,X          |    1D   |    3    |    4*    |
+  |  Absolute,X    |   ORA Oper,X          |    10   |    3    |    4*    |
   |  Absolute,Y    |   ORA Oper,Y          |    19   |    3    |    4*    |
   |  (Indirect,X)  |   ORA (Oper,X)        |    01   |    2    |    6     |
   |  (Indirect),Y  |   ORA (Oper),Y        |    11   |    2    |    5     |
@@ -1054,8 +1056,8 @@
   +----------------+-----------------------+---------+---------+----------+
   |  Zero Page     |   STA Oper            |    85   |    2    |    3     |
   |  Zero Page,X   |   STA Oper,X          |    95   |    2    |    4     |
-  |  Absolute      |   STA Oper            |    80   |    3    |    4     |
-  |  Absolute,X    |   STA Oper,X          |    90   |    3    |    5     |
+  |  Absolute      |   STA Oper            |    8D   |    3    |    4     |
+  |  Absolute,X    |   STA Oper,X          |    9D   |    3    |    5     |
   |  Absolute,Y    |   STA Oper, Y         |    99   |    3    |    5     |
   |  (Indirect,X)  |   STA (Oper,X)        |    81   |    2    |    6     |
   |  (Indirect),Y  |   STA (Oper),Y        |    91   |    2    |    6     |
@@ -1309,7 +1311,7 @@
         5A - Future Expansion           7A - Future Expansion
         5B - Future Expansion           7B - Future Expansion
         5C - Future Expansion           7C - Future Expansion
-        50 - EOR - Absolute,X           70 - ADC - Absolute,X
+        5D - EOR - Absolute,X           7D - ADC - Absolute,X
         5E - LSR - Absolute,X           7E - ROR - Absolute,X
         5F - Future Expansion           7F - Future Expansion
 
@@ -1326,7 +1328,7 @@
         8A - TXA                        AA - TAX
         8B - Future Expansion           AB - Future Expansion
         8C - STY - Absolute             AC - LDY - Absolute
-        80 - STA - Absolute             AD - LDA - Absolute
+        8D - STA - Absolute             AD - LDA - Absolute
         8E - STX - Absolute             AE - LDX - Absolute
         8F - Future Expansion           AF - Future Expansion
         90 - BCC                        B0 - BCS
@@ -1334,7 +1336,7 @@
         92 - Future Expansion           B2 - Future Expansion
         93 - Future Expansion           B3 - Future Expansion
         94 - STY - Zero Page,X          B4 - LDY - Zero Page,X
-        95 - STA - Zero Page,X          BS - LDA - Zero Page,X
+        95 - STA - Zero Page,X          B5 - LDA - Zero Page,X
         96 - STX - Zero Page,Y          B6 - LDX - Zero Page,Y
         97 - Future Expansion           B7 - Future Expansion
         98 - TYA                        B8 - CLV
@@ -1342,7 +1344,7 @@
         9A - TXS                        BA - TSX
         9B - Future Expansion           BB - Future Expansion
         9C - Future Expansion           BC - LDY - Absolute,X
-        90 - STA - Absolute,X           BD - LDA - Absolute,X
+        9D - STA - Absolute,X           BD - LDA - Absolute,X
         9E - Future Expansion           BE - LDX - Absolute,Y
         9F - Future Expansion           BF - Future Expansion

_Gist's changes are a little more extensive. A few typos are fixed, but the bulk of the changes are the addition of a summary section at the end.

--- 6502-102.txt	2013-10-08 22:03:48.000000000 -0400
+++ 6502-103.txt	2013-10-08 22:09:28.000000000 -0400
@@ -1,6 +1,7 @@
 6502 Microprocessor
 
  Revision 1.02 by _Bnu.
+ Revision 1.03 by _Gist.
 
  Most of the following information has been taking out of the "Commodore 64
 Programmers Reference Manual" simply because it was available in electronic
@@ -690,7 +691,7 @@
 
   DEY                   DEY Decrement index Y by one                    DEY
 
-  Operation:  X - 1 -> Y                                N Z C I D V
+  Operation:  Y - 1 -> Y                                N Z C I D V
                                                         / / _ _ _ _
                                  (Ref: 7.7)
   +----------------+-----------------------+---------+---------+----------+
@@ -745,7 +746,7 @@
 
   INY                    INY Increment Index Y by one                   INY
 
-  Operation:  X + 1 -> X                                N Z C I D V
+  Operation:  Y + 1 -> Y                                N Z C I D V
                                                         / / _ _ _ _
                                  (Ref: 7.5)
   +----------------+-----------------------+---------+---------+----------+
@@ -1365,7 +1366,7 @@
         CE - DEC - Absolute             EE - INC - Absolute
         CF - Future Expansion           EF - Future Expansion
         D0 - BNE                        F0 - BEQ
-        D1 - CMP   (Indirect@,Y         F1 - SBC - (Indirect),Y
+        D1 - CMP   (Indirect),Y         F1 - SBC - (Indirect),Y
         D2 - Future Expansion           F2 - Future Expansion
         D3 - Future Expansion           F3 - Future Expansion
         D4 - Future Expansion           F4 - Future Expansion
@@ -1738,3 +1739,95 @@
     SET_ZERO(src);
     AC = (src);
 
+Summary of 6502 Opcodes
+
+ADC   Add to accumulator with carry.
+AND   "AND" with accumulator.
+ASL   Arithmetic Shift Left. Bit0=0 C=Bit7.
+BCC   Branch on Carry Clear.
+BCS   Branch on Carry Set.
+BEQ   Branch on result Equal (zero).
+BIT   Test bits in memory with accumulator.
+BMI   Branch on result Minus.
+BNE   Branch on result Not Equal (not zero).
+BPL   Branch on result Plus.
+BRK   Forced BREAK.
+BVC   Branch on overflow Clear.
+BVS   Branch on overflow Set.
+CLC   Clear Carry flag.
+CLD   Clear Decimal mode.
+CLI   Clear Interrupt disable bit.
+CLV   Clear overflow flag.
+CMP   Compare with accumulator.
+CPX   Compare with X register.
+CPY   Compare with Y register.
+DEC   Decrement memory by one.
+DEX   Decrement X register by one.
+DEY   Decrement Y register by one.
+EOR   "Exclusive-OR" with accumulator.
+INC   Increment memory by one.
+INX   Increment X register by one.
+INY   Increment Y register by one.
+JMP   Unconditional Jump to new address.
+JSR   Unconditional Jump, saving return address.
+LDA   Load accumulator.
+LDX   Load X register.
+LDY   Load Y register.
+LSR   Logical Shift Right. Bit7=0 C=Bit0.
+NOP   No Operation.
+ORA   "OR" with accumulator.
+PHA   Push Accumulator on stack.
+PHP   Push Processor status register on stack.
+PLA   Pull Accumulator from stack.
+PLP   Pull Processor status register from stack.
+ROL   Rotate one bit Left (mem. or acc.).  C=Bit7 Bit0=C.
+ROR   Rotate one bit Right (mem. or acc.).  C=Bit0 Bit7=C.
+RTI   Return from Interrupt.
+RTS   Return from Subroutine.
+SBC   Subtract from accumulator with borrow.
+SEC   Set Carry flag.
+SED   Set Decimal mode.
+SEI   Set Interrupt disable status.
+STA   Store Accumulator in memory.
+STX   Store X register in memory.
+STY   Store Y register in memory.
+TAX   Transfer Accumulator to X register.
+TAY   Transfer Accumulator to Y register.
+TSX   Transfer Stack pointer to X register.
+TXA   Transfer X register to Accumulator.
+TXS   Transfer X register to Stack pointer.
+TYA   Transfer Y register to Accumulator.
+
+The Processor Status Register, "P"
+--- --------- ------ --------- ---
+
+7 6 5 4 3 2 1 0
+N V   B D I Z C
+
+7   N    Negative
+6   V    Overflow
+5        <..Future expansion..>
+4   B    BRK command
+3   D    Decimal mode
+2   I    IRQ disable
+1   Z    Zero
+0   C    Carry
+
+Addressing Modes of 6502 Assembly Code
+---------- ----- -- ---- -------- ----
+
+LDA  #$07       Immediate mode
+LDA  $1F        Zero page absolute
+LDA  $0800      Absolute
+CLC             Implied
+JMP  ($0036)    Indirect absolute
+LDA  $FE90,X    Absolute indexed (by X)
+LDA  $FE90,Y    Absolute indexed (by Y)
+LDA  $2A,X      Zero page indexed
+LDA  ($2A,X)    Indexed indirect
+LDA  ($2A),Y    Indirect indexed
+BCC  $03        Relative
+BCC  $0803      Relative (alternate form)
+LSR  A          Accumulator
+LSR             Accumulator (alternate form)
+

Unoffical codes

Can you also add the stable unofficial codes to this table (perhaps in italics so that you can know the difference)? --Zzo38 (talk) 19:59, 11 October 2013 (MDT)