Power Requirements/Code requirements

I’m trying to document with reference to electrical/building code citations the electrical supply requirements for desktops. Essentially how many desktops with monitors are permited by code on a 20 amp 110volt circuit?
We’re setting up a “temporary” (12+ months) work location with an ancient existing wiring system. Our construction manager claims he seen “8 or 10 desktops running off a single extension cord.”
I want to have no more than two desktops on a single permanently wired circuit, i.e. we need to spend some money on this project. Otherwise the PC’s won’t work and a fire hazard is created. Looks like I’ll need chapter and verse of the code requirements to persuade management.