In addition to this core RAM there was Core Rope Memory[1] which was used as the ROM for the Apollo Guidance computer amongst others. The cores were hand woven

In addition to this core RAM there was Core Rope Memory[1] which was used as the ROM for the Apollo Guidance computer amongst others. The cores were hand woven to program in the binary, a core could be wired to produce a 0 or 1 and any changes would require the core to be woven again. [1] https://en.wikipedia.org/wiki/Core_rope_memory https://en.wikipedia.org/wiki/Core_rope_memory