Imagine this hooked up to a PDP8!  or an Imsai! now
thats cookin. 
 The machines that this hooks to are a lot larger than the largest
 PDP-8. 8-) 
 
 There's no reason you couldn't hook this to, say, the P/370 that was just
 on eBay (and had a bus and tag port).  That's smaller than even an 8/e. 
 
Except that (if memory serves) this kind of coprocessing communications
aggregator would be able to pass more data than the P/370 has I/O bandwidth.
Anyway, I've seen many P/390 installations that are bigger than a PDP-8.
Peace...  Sridhar