Inventory of zeros of 5 bytes or more in the IIc Plus ROM

Main Bank
C1FB - 5 bytes
C4EE - 12 bytes
C5F3 - 5 bytes
C6FB - 5 bytes
C9A1 - 9 bytes
CFF9 - 7 bytes
Alt Bank
C572 - 8 bytes
C7FB - 8 bytes
C7FC - 7 bytes
CE00 - 512 bytes not usable (MIG space)
D134 - 76 bytes
D516 - 234 bytes
D6CE - 306 bytes
DB63 - 157 bytes
DE00 - 512 bytes maybe not usable (second mig space?), none of the firmware
       touches it.
F72D - 16 bytes not usable (some kind of data table)
F7ED - 19 bytes
FB3C - 196 bytes
FC3C - 12 bytes
FCC9 - 55 bytes
FE96 - 352 bytes, but reserve 65816 vectors