IBM PC - Hardware - Memory - 1501011 32KB Memory Expansion Option (1501011) Used to increase the memory beyond the 64KB on the PC system board. Item number: 1501011 Announcement date: 1981-08-12 Availability date: 1981-08-12 Announcement letter: 281-65 THE IBM PERSONAL COMPUTER From the announcement: Used to increase the memory beyond the 64KB on the system board by installing one or more of these options. Each option provides an additional 32KB of memory. The system board must first contain 64KB of memory before this option can be used. Each option requires a system expansion slot. Page created: 2021-08-12 Page last updated: 2023-10-02