Path: utzoo!utgpu!water!watmath!clyde!att-cb!ihnp4!upba!qetzal!rcw
From: rcw@qetzal.UUCP (Robert C. White)
Newsgroups: comp.sys.ibm.pc
Subject: Re: hooking PC's together
Message-ID: <1400@qetzal.UUCP>
Date: 27 Feb 88 02:16:27 GMT
References: <673@pasteur.Berkeley.Edu> <63200030@convexe> <1305@qetzal.UUCP> <3438@cup.portal.com>
Reply-To: rcw@qetzal.UUCP (0000-Robert C. White)
Organization: Mentor Software, Inc.
Lines: 45

In article <3438@cup.portal.com> Isaac_K_Rabinovitch@cup.portal.com writes:
>Robert, you missed something.  Landay needs a *parallel* connection,
>he doesn't have a spare RS232.  Also, 100K bps (careful with that
>word "baud") is fast, but couldn't parallel be faster?

Oops.
 
Isaac brings up an interesting point.  I always thought that 'baud'
and 'bps' were the same thing.  They aren't. Dragging out my trusty
(if old) Encyclopedia of Computer Science:

"A baud is a unit of signaling speed and refers to the number of
times the state (or condition) of a line changes per second.  It
is the reciprocal of the length (in seconds) of the shortest element
in signaling code... By contrast, a bit is the smallest unit of 
information in a binary system.  The baud rate is therefore 
equal to the bit rate only if each signal element represents one
bit of information...Unfortunately, in much of today's literature,
the term "baud" and "bits per second" are used synonymously."

>->Another product that will do this is 'Duette' from Platte River
>->Associates here in Denver. We have this product and it transfers
>->files at the rate of about 119,000 bps. That is not a typo.
>I've seen that rate on short RS232 connections before.  But some
>RS232 hardware won't go that fast.  Does PRA do a parallel product?
>                                                                 
>As I said before, I'm puzzled that the parallel approach isn't more
>popular.  Perhaps it's harder to implement.
>

I called PRA and talked to them this afternoon.  They are aware
of the parallel technology, but unfortunately it requires use of
a special adapter, and makes most sense on machines whose clocks
speeds exceed about 8 mhz as data is transmitted a nybble at a time.
In their opinion, the cost of the special adapter (and the costs
of supporting customers with it over the phone) negates the advantages
of parallel connections somewhat.  The correct rate of serial transfer
for Duette is exactly 115,200 bps. PRA is not aware of any customer
who has not successfully been able to use Duette on account of 
RS-232 hardware problems.
-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~    US SNAIL: 11534 Steele St, Thornton, CO.
} Robert White            {    MA BELL : (303) 252-9090
} ihnp4!upba!qetzal!rcw   {    HORSE   : Jct Platte River & Cherry Creek
~~~~~~~~~~~~~~~~~~~~~~~~~~~