This doesn't have anything to do with retro computers but with retro airplanes. The XB-70 was a hyper-sonic proposed in the 60s. It had a projected cruising speed of MACH 3, which is impressive even by today's standards. I remember as a kid I of having a model of this X plane. It was 60s cool if there ever was one. I got the below document from I'm not sure where. It's a 'what if' and some of the plans they had for the plane. Here's the NASA fact sheet on the plane. https://www.nasa.gov/centers/armstrong/news/FactSheets/FS-084-DFRC.html
Attached is the 'what if' document of the plans they had for the XB-70 for a Minuteman Missile launcher, an SST passenger plane and even a cargo variant.