I’ve presented some New York Times short films (including
Oculus made with the help of Annapurna) but here is a short film from the Wall
Street Journal today, “The Real Story Behind the Apollo 11 Computer Error”.
The narration concerns computer programmer Don Eyles, my
age, who walked into an MIT lab in 1966 (at the same time I had started
graduate school at KU) and asked for a job with no coding experience.
He wound up writing the memory-efficient “lapidary”
assembler or machine code that the lunar module would use. It was fit into six sequential pieces of
“core rope”, each 36K, presumably each with its own register (rather like base
register concepts in IBM mainframe assembler code which I worked on in the
1980s and 1990s and which the IRS still uses a lot of today – I know that from
oral job interviews in the 2000s; coding
“out of addressability” was a good trick).
I actually wrote some similar shipboard code for NAVCOSSACT (Washington
Navy Yard) in 1972, but never implemented it, as I took a job with Univac, and
office mates went down to Charleston SC and boarded a ship later to implement
it. I had actually learned FORTRAN code
in summer jobs at the David Taylor Model Basin (Maryland, on the DC Beltway) in three summers starting in
1965 and small computers existed then.
He says he almost became a life insurance salesman (like an
agent?) That’s ironic.
The core ropes were among the first use of integrated
circuits in computers. Up to that time,
IBM (and to some extent Sperry Univac and Burroughs) had dominated the
mainframe business market with systems that filled whole computer rooms (like
the 1110 benchmark I worked on in St Paul MN in the spring of 1974).
The failure was caused by signals from nearby hardware with
a switch that malfunctioned.
Eyles says this was a sickening moment, just three years
after starting work. But Mission Control in Houston figured out that his code
still worked and the problem was external and that the astronauts would be able
to land. The rest is history.
No comments:
Post a Comment