The MIT Press has published a fairly large set of books, mostly about IBM, that I found very useful for understanding the 1950s (and for IBM the early-mid 1960s as in the System/360). I would start with Project Whirlwind: The history of a pioneer computer by Kent C Redmond, that's a Digital Press as in DEC book, that computer by and large defined a great many standards in the way we build computers to this day, and that project also developed the first sane type of RAM, core memory.

The MIT Press books describe IBM starting in the punched card data processing era, how the above intersected with IBM in the SAGE project, and much more. IBM defined a great deal of what was used for a long time by many companies due to a previous punched card anti-trust settlement which required them to FRAND license their patents. So their electromechanical wizzardry turned to computer systems like the half-inch reel to reel tape became ubiquitous, was still the thing in the first part of my computing career.

DEC also published some good books about its history, I can look those up if you want.

These are some of the topics I've found to be very interesting, there's of course lots more published by them and others. But I like to focus on what became wildly successful, or what caused a company like IBM to falter very badly like when it become dogmatic in the System/360 days that virtual memory was a bad thing and would not be supported, in one stroke costing them the high end academic market and eventually resulting in their becoming a niche player.

For DEC, a study of the PDP-6/10 and PDP-11 is a necessity if you want follow my interests, the former became a dominant replacement for IBM computers, the latter was the system UNIX first became big on.