I became an Intel Field Application (FAE) engineer in 1988, just 7 years after the PC. At my first internal tech conference in Phoenix I was told that the reason IBM used the 8088 over the Motorola 6502 they were also looking at was because the local Intel FAE lent them an 8088 emulator. These things were a pin-for pin replacement for the chip and were the hardware equivalent of a software debugger, with single-stepping, register inspection, breakpoints etc. Having one would have made development of the motherboard that much easier and quicker. This seemed to be common knowledge in the FAE community, but never mentioned by IBM or Intel higher ups. Who knows which version is true, but perhaps a design decision based on the serendipitous fact that the FAE had a loan stock emulator in the trunk of his car when he visited the IBM team was not the story that either company wanted written.