Scott Alfter wrote ...
The IBM PC was never an 8-bit machine. It had an 8-bit expansion bus, but
the 8088 was a 16-bit processor with an 8-bit data bus (like the 65816).
Later processors with a bus width less than the machine word size were the
386SX and 486SLC, which were 32-bit processors with 16-bit data buses.
The IBM PC, PC/XT, and similar computers based on the Intel 8088
microprocessor work with a 16-bit word size but use an 8-bit data bus. For
this reason, they are sometimes considered one step above 8-bit machines and
one step below 16-bit machines. However, generally such machines are called
8-bit machines because the size of the data bus limits the machine's overall
speed.