diff --git a/doc/isa.org b/doc/isa.org
index 7a36b8e..ec0c0d4 100644
--- a/doc/isa.org
+++ b/doc/isa.org
@@ -61,7 +61,7 @@ A size and a literal operand is given immediately after the instruction.
 | 3- | BMI rel  | AND ind,Y |       |    |    |    |    |    | SEC impl | AND abs,Y |          |    |           | AND abs,X | ROL abs,X |    |
 | 4- | RTI impl | EOR X,ind |       |    |    |    |    |    | PHA impl | EOR #     | LSR A    |    | JMP abs   | EOR abs   | LSR abs   |    |
 | 5- | BVC rel  | EOR ind,Y |       |    |    |    |    |    | CLI impl | EOR abs,Y |          |    |           | EOR abs,X | LSR abs,X |    |
-| 6- | RTS impl | ADC X,ind |       |    |    |    |    |    | PLA impl | ADC #     | ROR A    |    | JMP ind   | ADC abs   | ROR abs   |    |
+| 6- | RTS impl | ADC X,ind | PER?  |    |    |    |    |    | PLA impl | ADC #     | ROR A    |    | JMP ind   | ADC abs   | ROR abs   |    |
 | 7- | BVS rel  | ADC ind,Y |       |    |    |    |    |    | SEI impl | ADC abs,Y |          |    |           | ADC abs,X | ROR abs,X |    |
 | 8- |          | STA X,ind |       |    |    |    |    |    | DEY impl |           | TXA impl |    | STY abs   | STA abs   | STX abs   |    |
 | 9- | BCC rel  | STA ind,Y |       |    |    |    |    |    | TYA impl | STA abs,Y | TXS impl |    |           | STA abs,X |           |    |
@@ -86,3 +86,11 @@ A size and a literal operand is given immediately after the instruction.
 |--------|------|-------|
 | opcode | attr | value |
 
+** Instructions Listing
+
+- ADC :: add with carry
+- AND :: and (with accumulator)
+- ASL :: arithmetic shift left
+- BCC :: branch on carry clear
+- BCS :: branch on carry set
+- BEQ :: branch on equa (zero set)