Did you work at Atari? Don't know if you saw the Atari documentary, but it looked total madness.
Mind you that was the '80s.
When I worked in a software department in the 90's a long liquid lunch on Friday was standard. Coding bugs could be quite easily detected by reviewing Friday pm code first.
No, it was the electricity board. In those days computer departments were in their infancy and full of young people, and had a different vibe to the more established departments.
We used to have regular Friday afternoon Olympics in the office that included running around it and the perimeter of the building, jumping over desks and throwing objects into wastepaper bins from increasing distances.
At one time two colleagues were having a cosy work related meeting in a store room at the back of the main conference room when a large meeting started. They had to stay there all afternoon and we kept adding to their embarrassment by sending tannoy announcements for them.
We would have fitted into the Downing St. culture very well, and I left after four years.