Here is a list of all related documentation pages:

GE-120 C ABI
GE-120 Unified Binary Format
Operating the GE-120 Console
GE-120 micro-sequencer flow charts → gemu state map & fidelity audit
funktionalcpu deck — annotated disassembly & routine names
GE-120 / GE-130 Instruction Set Architecture
Integrated peripherals (channels 1 and 2)
GE-120 Punched-Card Formats — Decoding Notes
GE-120 signal reference
Todo List