Also, it was super common practice to just go direct to undocumented internals. You didn't have a clean API to duplicate, you had all the untamed glory of a CPU

Also, it was super common practice to just go direct to undocumented internals. You didn't have a clean API to duplicate, you had all the untamed glory of a CPU with no MMU to deal with, and all the programs that did shonky things because they worked.