Table schema:
CREATE TABLE table_name_68 (memory_map VARCHAR, model VARCHAR, byte_string VARCHAR, max_memory__kwords_ VARCHAR)

Question: On a Sigma 9 with a standard byte string and more than 128 max memory, what is the value of the memory map?
SQL: SELECT memory_map FROM table_name_68 WHERE byte_string = "standard" AND max_memory__kwords_ > 128 AND model = "sigma 9"