the statement is true... PCs don't do realtime. the 8051 you're working on (or the leftovers from a previous project) DO.

the 8051 unit that you are building is usually the best fixture to use for supporting its testing.

i just use the same board, sometimes with extra circuitry populated, to handle fixture needs. those 8051s just pipe the information back through a comm port on a pc which holds any necessary man machine interface appropriate for whatever requirements of idiot-operation.

in fact, we include the special fixture requirements on our prototype pcb layout, we never have a un-utilized snapoff section of a pcb panel. :)

the project i just completed had a snapoff corner measuring .75x.75inches and i used it to do a flash programmer cable converter from a previous test fixture. it now mates through it to the new system which was a much tighter layout.

doing that beats hiring a techie to build cables and whine about the good old days of one shots, and 555 timers.

duh