0xB1 ( 177 )  Extended Keys 1
  
BitsDescription
71 if DELETE pressed
61 if EDIT pressed
51 if BREAK pressed
41 if INV VIDEO pressed
31 if TRUE VIDEO pressed
21 if GRAPH pressed
11 if CAPS LOCK pressed
01 if EXTEND pressed

* Nextreg 0x68 bit 4 stops extended keys from making entries in the 8x5 matrix