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Update README.md
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@Lewpen
Lewpen authored Sep 28, 2024
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Expand Up @@ -90,6 +90,36 @@ The actual distinct expressions for the updates to registers et al. are few enou
| 23 | X | writeWordAddress | Address where a word is written in memory |
| 24 | Y | writeWordValue | The value that is written to the memory word |

Here with some example values from the `ORA ($LL, X)` instruction (opcode `0x01`):

| Index | Position | Header Title | Description | Example Value (ORA ($LL, X)) |
|-------|----------|------------------------------|-----------------------------------------------------------------------------|-----------------------------------------|
| 0 | A | Bytes | The opcode bytes of the instruction and its arguments | 01 LL |
| 1 | B | Name | Instruction mnemonic, e.g., BRK, ORA, etc. | ORA |
| 2 | C | Cycles | Number of CPU cycles the instruction takes | 6 |
| 3 | D | Args | The arguments used by the instruction, e.g., immediate, zero-page, etc. | ($LL, X) |
| 4 | E | Description of the instruction| A short description of what the instruction does | Bitwise OR between A and byte at address (LL + X) |
| 5 | F | zeroPageWordAddress = | Address used to perform zero-page word memory access, results in readByte | LL + X |
| 6 | G | readByteAddress = | Address used to perform a byte read from memory, results in readByte | zeroPageWord |
| 7 | H | readWordAddress = | Address used to perform a word read from memory, results in readWord | |
| 8 | I | result (word) = | The result of the operation, affects flags and registers | A | readByte |
| 9 | J | A = | The new value of the accumulator after the operation | result |
| 10 | K | X = | The new value of the X register after the operation | |
| 11 | L | Y = | The new value of the Y register after the operation | |
| 12 | M | SP = | The new value of the stack pointer after the operation | |
| 13 | N | PC = | The new value of the program counter after the operation | PC + 2 |
| 14 | O | carry = | The new value of the carry flag | carry |
| 15 | P | zero = | The new value of the zero flag | result == 0 |
| 16 | Q | interrupt = | The new value of the interrupt disable flag | interrupt |
| 17 | R | decimal = | The new value of the decimal mode flag | decimal |
| 18 | S | break = | The new value of the break command flag | |
| 19 | T | overflow = | The new value of the overflow flag | overflow |
| 20 | U | negative = | The new value of the negative flag | result >> 7 |
| 21 | V | writeByteAddress | Address where a byte is written in memory | |
| 22 | W | writeByteValue | The value that is written to the memory byte | |
| 23 | X | writeWordAddress | Address where a word is written in memory | |
| 24 | Y | writeWordValue | The value that is written to the memory word | |

### Go Language Support

#### func Emulate6502( A *uint8, X *unit8, Y *unit8, SP *unit8, PC *uint16, SR *uint8, memory *byte[]) bool
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