Real-world elements used to portray the fictional computer in Colossus: The Forbin Project (1970) [closed]

The opening sequence of "Colossus: The Forbin Project" (1970) starts with close-ups of electronics, progressing up to a console of an IBM 1620, and eventually to a giant hall where "Forbin" (Eric Braeden) is first seen. I am curious specifically about two things:

1. Something that looks to me like a giant multi-platter disk drive (behind a tall glass enclosure)... movement can be seen (what looks to me like read/write heads seeking in and out)... is that what it is, and if so, was it actual computer equipment of the day, or a studio-built/commissioned prop?
2. The hall of "computer banks". I have no doubt that much of the "hall" is painted matte, although patterns of flashing lights can be seen, and the whole hall appears to light up in a sequence. How was that shot put together? What parts of the shot were physical props and what was artwork and/or visual effects? And for the props, what was existing equipment and what was studio-constructed? I am excluding from my question the large "console" bearing the embossed "COLOSSUS" name at the top - it's not all that mysterious what is going on there.