Arguing that you can program an FPGA to look like
anything you'd like
seems to me to be akin to saying that one can microprogram a 360/30
to have any old instruction set imaginable or program an emulator to
run on a DG Nova to emulate any instruction set that one cared for.
Nice question...any "big iron" implementation in FPGA? S/360? S/370?
PDP? VAX? Whatever?