diff --git a/src/SGB_Command_Packet.md b/src/SGB_Command_Packet.md
index e0a10d36..bc7d2211 100644
--- a/src/SGB_Command_Packet.md
+++ b/src/SGB_Command_Packet.md
@@ -1,16 +1,17 @@
 # Command Packet Transfers
 
-Command packets are transferred from the Game Boy to the SNES by using bits 6 and 7 of of [the `JOYP` register][JOYP].
+Command packets are transferred from the Game Boy to the SNES by using bits 4 and 5 of of [the `JOYP` register][JOYP].
+These lines are normally used to select one of the two button groups (which [still works as usual][JOYP]).
 
 ## Transferring Bits
 
-A command packet transfer must be initiated by setting [`JOYP`][JOYP] bits 6 and 7 both to 0; this will reset and start the ICD2 packet receiving circuit.
-Data is then transferred (LSB first), setting bit 6 to 0 will indicate a `0` bit, and setting bit 7 to 0 will indicate a `1` bit.
+A command packet transfer must be initiated by setting [`JOYP`][JOYP] bits 4 and 5 both to 0; this will reset and start the ICD2 packet receiving circuit.
+Data is then transferred (LSB first), setting bit 4 to 0 will indicate a `0` bit, and setting bit 5 to 0 will indicate a `1` bit.
 For example:
 
 {{#include imgs/sgb_bits.svg}}
 
-[The boot ROM](<#Super Game Boy (SGB, SGB2)>) and licensed software keep data and reset pulses LOW for at least 5 M-cycles and leave bit 6 and 7 both to 1 for at least 15 M-cycles after each pulse.
+[The boot ROM](<#Super Game Boy (SGB, SGB2)>) and licensed software keep data and reset pulses LOW for at least 5 M-cycles and leave bit 4 and 5 both to 1 for at least 15 M-cycles after each pulse.
 Though the hardware is capable of receiving pulses and spaces as short as 2 M-cycles (as tested using [sgb-speedtest]), following the common practice of 5 M-cycle pulses and 15 M-cycle spaces may improve reliability in some corner case that the community has not yet discovered.
 
 :::tip
diff --git a/src/imgs/sgb_bits.svg b/src/imgs/sgb_bits.svg
index 006af128..f9a8873b 100644
--- a/src/imgs/sgb_bits.svg
+++ b/src/imgs/sgb_bits.svg
@@ -29,8 +29,8 @@
     <line x1="430" y1="0" x2="430" y2="100"/><line x1="440" y1="0" x2="440" y2="100"/>
   </g>
   <text x="90" y="10"  class="right">Transmitted</text>
-  <text x="90" y="42"  class="right">JOYP bit 6</text>
-  <text x="90" y="72"  class="right">JOYP bit 7</text>
+  <text x="90" y="42"  class="right">JOYP bit 4</text>
+  <text x="90" y="72"  class="right">JOYP bit 5</text>
   <text x="90" y="110" class="right">M-cycles</text>
   <path d="M110,30 h20 v20 h10 v-20 h30 v20 h10 v-20 h30 v20 h10 v-20 h110 v20 h10 v-20 h70 v20 h10 v-20 h20 m2,0 h2 m2,0 h2 m2,0 h2"/>
   <path d="M110,60 h20 v20 h10 v-20 h110 v20 h10 v-20 h30 v20 h10 v-20 h70 v20 h10 v-20 h60 m2,0 h2 m2,0 h2 m2,0 h2"/>