Tangentially related: is there a history covering IBM's development of microcomputers? It is clear that the traditional story of the development of the IBM PC leaves out many important details. There the 5100/5110/5120, which goes back to the mid-1970's and reflects the stereotype of IBM. There is also the System/23 DataMaster, where the hardware seems to be the basis of the IBM PC. This seems to go against the traditional story that the IBM PC was some sort of renegade project. (If anything, they appear to be companion projects. The main difference being the DataMaster's focus upon IBM firmware/software.)
Like I need another big project :-)
The IBM Datamaster is an interesting system, but it was doomed. It had an 8-bit Intel 8085 processor, cost $9000, and came out in July 1981. The IBM PC had a 16-bit 8088 processor, cost $1565, and came out a month later. So there was no reason to buy a Datamaster
There's a good description of Datamaster in "A Personal History of the IBM PC" by Dave Bradley (one of the PC's designers). Unfortunately, it's paywalled.[1]
[1] https://doi.ieeecomputersociety.org/10.1109/MC.2011.163
That sounds like a great starting point. There's a university library 500 meters from where I work, so bypassing the paywall ought to be easy.
And thank you for all of your articles over the years. They border so close to applied physics they are fascinating reads.