The Z-Machine Standards Document 1.
Static memory follows immediately on.
The contents of this are given later but note that games are not permitted to alter many bits inside it. It is legal for games to alter any of the tables stored in dynamic memory above the header, provided they leave the tables in legal states. 1.1.2 Static memory can be read using the opcodes loadb and loadw . It is illegal for a game to attempt to write to static memory. A byte address specifies a byte in memory in the range 0 up to the last byte of static memory.