[link|http://www.ox.compsoc.net/~swhite/history/timeline-PRODUCT.html#139|http://www.ox.compso...-PRODUCT.html#139]

1979 IBM announced it was working on a PC to compete with other Microcomputers.

[link|http://www.ox.compsoc.net/~swhite/history/timeline-CPU.html#146|http://www.ox.compso...line-CPU.html#146]

1981 the 80186/80188 chips were released. Question mark here.

[link|http://www.ox.compsoc.net/~swhite/history/timeline-PRODUCT.html#147|http://www.ox.compso...-PRODUCT.html#147]

1981 the IBM PC was released with the 8088 CPU.

Intel timeline:
[link|http://www.intel.com/pressroom/kits/quickrefyr.htm|http://www.intel.com...ts/quickrefyr.htm]

80186 did not come out unil 1982. One year after the IBM PC did. Unlikely it was used as a prototype for the IBM PC unless the 80186 CPU was a prototype itself back then and shared outside of Intel. Maybe IBM went with the 8088 because the 80186 would not be in production until a year later? The 80188 was a 8 bit bus, IIRC.

If memory serves, before the IBM PC was the IBM Displaywriter. [link|http://www-1.ibm.com/ibm/history/exhibits/pc/pc_8.html|http://www-1.ibm.com...bits/pc/pc_8.html]

Check out the other systems that existed before the IBM PC, it shows that IBM was trying to make desktop computers before the IBM PC.

I thought when you said it was as close to a PC without being a PC that it was a prototype before the PC was released. It had to become a prototype after the PC was released based on the Intel timeline. No mention of it at IBM that I can find.