Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!tut.cis.ohio-state.edu!bloom-beacon!apple!rutgers!bellcore!texbell!merch!cpe!hal6000!trsvax!uhclem
From: uhclem@trsvax.UUCP
Newsgroups: comp.sys.tandy
Subject: Re: what is the TandyLink board?
Message-ID: <193300110@trsvax>
Date: 7 Mar 89 15:27:00 GMT
References: <107@toybox.UUCP>
Lines: 45
Nf-ID: #R:toybox.UUCP:107:trsvax:193300110:000:2259
Nf-From: trsvax.UUCP!uhclem    Mar  7 09:27:00 1989


<>
B>  In the latest Radio Shack catalog (pg. 178), there is an entry for
B>something called the "TandyLink Board Plus".  It appears to be a
B>low-cost LAN interface of some kind.  A friend is looking to set up
B>a small LAN in his house, and would any info on this system.  It

Tandylink is an "almost" clone of the TOPS "Flashtalk" board, right down to the
strap options.  (Biggest difference is that the transformer is on the
board instead of external.)  It uses a 8530 SCC and is normally run in SDLC
mode.  The communication method is modified RS-485 (multinode RS-422).
This is the near-ultimate "stupid" board.  It requires DMA every 10.3 usec,
causing havoc with some floppy operations.  

Tandy and Macintosh use shielded twisted pair wiring, while PhoneNET (from
Farallon) uses unshielded twisted pair (phone wire), at a big savings.
In the networks I take care of, I have 800+ ft of unshielded wire
connecting Tandylink adapters, running at 768kbps.  With shielded wire,
reduce the length to 500 ft at that speed.  "Normal" Appletalk runs
at 230 kbps.  Of course, that is the rate of data transfer, while all
of the arbitration timing remains the same and is the bulk of time used,
so it is not three times faster in performance than Appletalk.

Tandy apparently offers a private NETBIOS layer and/or a 3com stack.
I do not think they have a fully transparent bridge between the two,
although there is no reason why you can't buy the software from Tops
or Kinetics, since they do have bridging software.  Tandy does not offer
something that will converse with Macintoshes or other "A"-word computers.
Again, Tops and other vendors do.

The "plus" board is a board with a different bus connector so that it
can be plugged into a 1000 EX/HX system.  Useless on any other computer.
The "non-plus" board is what fits in a PC.   Both require one DMA
channel and one interrupt.

There are lots of trademarks and other reserved-money words here. So,
%s is a registered trademark of %s.

<My opinion, and not that of my employer who really wasn't interested
 in my protocol changes to double the performance...>
						
					"Thank you, Uh Clem."
					Frank Durda IV @ <trsvax!uhclem>
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