The biggest pain on implementing ieee-488 was the lack of any standardisation on both, software and hardware.

E.g. the is any fredom to use whatever you think to mark the end of data:
- using the wire named EOT
- using a single character e.g. 0x0A, 0x0D or any other
- using a couple of characters, e.g. 0x0A + 0x0D
- using all these together


There is no exact timing on the bus specified.
E.g. if you change from talker to listener or reverse, there is no time named to put the bus in treestate from the last talker and to activate the bus from the new talker.
So I assume it is often possible that different data are figthing on the bus.

And today for noisy environment, its more and more important for human security and also for reliability, that the devices can be optically insultated one from the other.
But how you can insulate 16 bidirectional lines economically ?


So my conclusion:

Marrying the devils grandmother was less painful as using the ieee-488.


Peter