Editing Game Boy Printer (section)

=== Packet Format ===
Communication is via the Game Boy sending to the printer a simple packet structure as shown below. In general, between the first "sync_word" til the checksum is the Game Boy communicating to the printer. The last two bytes of the packet are for the printer to acknowledge and show its current status code.

<!--

  | BYTE POS :    |     0     |     1     |     2     |      3      |     4     |     5     |  6 + X    | 6 + X + 1 | 6 + X + 2 | 6 + X + 3 | 6 + X + 4 |
  |---------------|-----------|-----------|-----------|-------------|-----------|-----------|-----------|-----------|-----------|-----------|-----------|
  | SIZE          |        2 Bytes        |  1 Byte   |   1 Byte    |  1 Bytes  |  1 Bytes  | Variable  |        2 Bytes        |  1 Bytes  |  1 Bytes  |
  | DESCRIPTION   |       SYNC_WORD       | COMMAND   | COMPRESSION |     DATA_LENGTH(X)    | Payload   |       CHECKSUM        |    ACK    |  STATUS   |
  | GB TO PRINTER |    0x88   |    0x33   | See Below | See Below   | Low Byte  | High Byte | See Below |       See Below       |    0x00   |    0x00   |
  | PRINTER TO GB |    0x00   |    0x00   |    0x00   |   0x00      |    0x00   |    0x00   |    0x00   |    0x00   |    0x00   |    0x81   | See Below |

-->

{| class="wikitable"
|-
! Byte Position !! 0 !! 1 !! 2 !! 3 !! 4 !! 5 !! 6+X !! 6+X+1 !! 6+X+2 !! 6+X+3 !! 6+X+4
|-
| Size || 2 bytes || 2 bytes || 1 byte || 1 byte || 1 byte || 1 byte || Variable || 2 bytes || 2 bytes || 1 byte || 1 byte
|-
| Description || SYNC_WORD || SYNC_WORD || COMMAND || COMPRESSION || DATA_LENGTH(X) || DATA_LENGTH(X) || Payload || CHECKSUM || CHECKSUM || ACK || STATUS
|-
| GB TO PRINTER || 0x88 || 0x33 || See Below || See Below || Low Byte || High Byte || See Below || See Below || See Below || 0x00 || 0x00
|-
| PRINTER TO GB || 0x00 || 0x00 || 0x00 || 0x00 || 0x00 || 0x00 || 0x00 || 0x00 || 0x00 || 0x81 || See Below
|}

* Command may be either Initialize (0x01), Data (0x04), Print (0x02), or Inquiry (0x0F).
* Payload byte count size depends on the value of the `DATA_LENGTH` field.
* Compression field is a compression indicator. No compression = 0x00
* Checksum is a simple sum of bytes in command, data length, and the data payload.
* Status byte is a bit-field byte indicating various status of the printer itself. (e.g. If it is still printing)