QRZ! Ham Radio 5/QRZ Ham Radio Callsign Database - Volume 5.iso/digests/tcp/940130.txt

Internet Message Format | 1994-11-13 | 8.5 KB

Date: Sun, 26 Jun 94 04:30:02 PDT
From: Advanced Amateur Radio Networking Group <[e-mail]>
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Subject: TCP-Group Digest V94 #130
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TCP-Group Digest            Sun, 26 Jun 94       Volume 94 : Issue  130

Today's Topics:
                            NOS and the PC
                           Routing Project

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We trust that readers are intelligent enough to realize that all text
herein consists of personal comments and does not represent the official
policies or positions of any party.  Your mileage may vary.  So there.
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Date: Sat, 25 Jun 1994 11:41:46 -0600 (MDT)
From: Klarsen <[e-mail]>
Subject: NOS and the PC
To: [e-mail]

    It has been interesting watching the emergence of thought about
using a stripped down PC as the TNC of the 1980's. I did like the cost
estimates that made sure the tnc-2 from TAPR would be successful.

    Running these same cost estimates now says run a PC and load the
switch software. Here is where we have a problem. The PC is cheap and we
can all write code for it with our Borland or Microsoft systems. But in
fact we can't get the data from the computer to our RADIO with software...

    So the parts of the tnc which are not a part of the PC need to be
made in the hardware sense. I bought a drsi board and it is in operation
at this moment. This is a form of the tnc parts the PC left out. But it
is expensive. I know this could be made available in kit form for less
cost. It is just a problem to get even this done.

    Now if you were building a switch for some mountain top  today
what would a smart person do? On a mountain top a smart person would buy
1 to 4 tnc-2's and radios and hope the lightning isn't too bad this
summer. This is because making a PC survive in the wilds is an art not
reported on much. There is one on Mt. Bigello above Tucson, AZ that is
running the G8BPQ switch and a drsi card and some tnc-2 in kiss mode. The
guy who did this a few years ago is not sure it was a good idea. But then
PC's were not cheap then...

    Assuming we can make this PC live in the mountains with the
equivelent of,if not exactly an autoexec.bat file to bring it back on
line when power returns we face the same problem: do we drive tnc-2's
with the kiss e-prom or use a drsi card? Where is the economy coming
from? We get the PC cheap. We get the tnc or drsi not-so-cheap. The node
gets more expensive...

    So it is plain the problem comes down to making a plug-into the
PC card that has the modem and low level packet forming/reading hardware.
I suggest this is where a lot of free time from us hams can pay off. If
we get thinking about making high speed modems on a pc card it gets to be
fun. No problems trying to get clocks and stuff. It's all there on the pc
bus. Think about sending really fast packet. But make it possible to use
the available 1200 baud modem chip if needed.

    Now NOS. The experiance I have had says nos is not stable under
high use enviorments. We have a internet chat system in Las Cruces, NM
that gets a lot of use forwarding bbs traffic, allowing Russian and other
DX stations to use my bbs and the more common chat mode. Both aa5dl and
f6cnb have daily problems keeping NOS running. I have no problem with my
NOS since it is only used as a bbs and ocassional smtp or ftp; it runs
for weeks without crashing. But those with super heavy use will crash in
a matter of hours. So what's needed if not already here but unknown to
me is a nos that is as stable as dos. If this can be done then nos will
work fine as a switch from my experiance.

    But out there right now is the G8BPQ switch which I have running
and has NEVER CRASHED! Unless we need something better than netrom under
ax.25 this is the best thing available.

    To long already but hope it makes sense.

73 de karl [e-mail]

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Date: Sat, 25 Jun 1994 10:34:44 -0500 (CDT)
From: [e-mail] (Steve Sampson)
Subject: Routing Project
To: [e-mail]

[e-mail] (Adrian Godwin) writes:
> But encapsulate the OS dependencies with a view to removing the OS
> altogether : on a system that has no applications, what does DOS
> do to justify it's memory usage after it's loaded NOS ?

We're only talking 30k here.  30k is low enough to be insignificant (5%).
Anyway DOS is the "Glorified Bootstrap Loader" we need :-)

I've since revised the limits to include FTP.  That way you could FTP
a new version and then reset remotely.  But in any case, I don't want
to write low level code for the PC components.  This is supposed to be
cheap, not high tech.  Remember, we decided that mass production CPU
boards are to be used.  If I wanted to write low level code for a floppy
or other such necessities I'd start with a new design...

Alan Cox reports that his group is nearing completion of a Linux design
that could run in 2 Meg and a floppy.  I like this idea much better, being
an advocate of using better code.  For example the TCP/IP is probably no
better than Phil's, but the support code is (domain, NFS, etc).  Hopefully
they will be able to release a floppy image.

> Serial ports have some utility, even if you ban KISS TNCs - you can handle
> your telephone line comms on the same (shack) router.

That was my intention.  To get off the single character at a time logic in
NOS, and do bulk transfer.  That serial code is terrible, and the performance
is terrible (I've been able to NOS up to 4800 baud without overruns).  I looked
at redesign of that part, but it's a major change.

> Ummm. I know your proposal is a gnat's whisker from a NOS switch anyway,
> but if it's better to spend money than redevelop existing solutions, there's
> already a NOS-in-a-box from Gracilis. No DOS dependency, good performance,
> ethernet Real Soon Now. Would it be as cheap as that PC if everybody
> in the market for a TNC from hell bought one ? 68302s are finally available
> in cheap packaging ..

I think it's more than a whisker. I was thinking of the Gracilis P-10 when I
specified that there would be no "interactive mode" such as used in NOS.
It doesn't have to be Telnet (just an idea) and maybe a simple AX.25 connection
would be good enough.  Anyway the remote command mode in NOS is the only area
that needs to be modified in order to bring it out as the main console.

This designs advantages are that anyone could build a P-10 with off the shelf
parts.  The advantage of doing it this way is that you won't have to wait for
Gracilis to implement anything.  You have Ethernet and PI2 off the shelf now,
and the complete design is probably half the cost of the P-10 and does exactly
the same thing. I don't mean to denegrate Gracilis, but the group here has
found that "Just use a PC" is the only economical way to go.  Waiting for
others to improve or design a switch using modern technology has proven too
expensive.  Just look at all the designs in the ARRL Computer Conferences.
The way they were written was that the gadget would be in production by the
time you read about it.  The actual case was that they never left the garage
design stage, and did not exist.  But even if the design never reached
economic feasability, at least they expounded a design philosophy that was
correct and interesting to follow.  The AWACS radar computer design was
developed in 1969 and is a one-of-a-kind DMA driven core memory general
purpose computer (I think the designers are all dead - the logic devices
"MECL" certainly are. This was my first experiance to never buy digital devices
which start with 'M') device. It runs at 10 MHz and could probably run rings
around any 66 MHz PC in I/O.  But the upgrade computer was taken off the shelf.
Rather than re-invent the wheel (which Westinghouse really wanted - they
designed a new computer from scratch) the Air Force specified that it should
be a current Mil-Spec computer.  Westinghouse just plugs two of these into the
equipment rack and saves millions.  It's not what they want, it's all they can
afford. On that note, I'll agree, it's all we can afford - to use a PC.
--
Steve

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End of TCP-Group Digest V94 #130
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