MIKE ROSS wrote in a message to Roy J. Tellason:

 MR> "Roy J. Tellason" wrote to "Greg Mayman" (16
Dec 02  20:06:09)  ---
 MR> on the topic of "THOSE OLD EXPENSIVE [2/2]"

 RJT>  Anyhow,  TeleVideo took a different
 RJT> approach,  where they put the smarts for stuff in other boxes,  that
 RJT> they called "workstations".  So like an 803 would be a
z80 cpu with
 RJT> 128k of ram and a couple of floppy drives.  The connection between
 RJT> them would use a 15-conductor (!) cable,  of which I have one that's
 RJT> either 25 or 50 feet.  I forget what they're doing there,  it's RS-485
 RJT> or -422 or something like that.  Some bizarre chips interfacing there
 RJT> that I've never seen in anything else.  (Sure would be nice if they
 RJT> were pin-compatible with the 1488 and 1489... :-)

 MR> No, because the 148x are single-ended unbalanced
 MR> receiver/tranmitters while your RS-485 is a balanced system which
 MR> requires dual-ended or balanced receiver/transmitters. Besides the
 MR> protocols tend to be funky too. This means one can't simply slap
 MR> together an adapter box without the smarts in it to do the protocol
 MR> translation. It's a real pita to do! 

I was just thinking that it would be nifty to have a box that had that many
serial ports in it...

There was a guy who designed an S-100 board that had four,  using of all
things 8250 chips.  I forget if it was in Byte magazine or what...  I
actually spoke to him on the phone once,  and his asking price on even a
blank board was *way* up there,  considering that things had moved well
into clone hardware by that time.  He spoke of trying to recover his design
costs,  and I wished him luck.  

I actually have a couple of cards for ISA bus that'll hook up to that
interface.  One has a rom,  the other one doesn't.  The problem with that
is that the rom wants to boot of the 816!  That means having an image over
there for it to boot,  and that's a whole 'nother issue...

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