The programs that ran on the Apollo Guidance Computer were written this way. If there was a sufficiently bad error, the AGC would restart execution. The program

The programs that ran on the Apollo Guidance Computer were written this way. If there was a sufficiently bad error, the AGC would restart execution. The programs took advantage of the memory in use at the time being non-volatile, and not reset to zero when the computer restarted, so the program could figure out what the CSM or LM was doing, and continue it. This actually happened on Apollo 11. The 1201 and 1202 program alarms were the computer overloading, and running out of space for more processes. When this happened, the computer would reset, and navigation would pick up again.