"Roy J. Tellason" wrote to "Greg Mayman" (16 Dec 02  20:06:09)
 --- 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... :-)

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

 Mike
 ****

... Modulation in all things...
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