Path: utzoo!utgpu!attcan!uunet!lll-winken!lll-ncis!helios.ee.lbl.gov!pasteur!ucbvax!UREGINA1.BITNET!CRONEJP
From: CRONEJP@UREGINA1.BITNET (Jonathan Crone)
Newsgroups: comp.sys.amiga
Subject: CheapNet
Message-ID: <8901062235.AA12520@jade.berkeley.edu>
Date: 6 Jan 89 21:10:31 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Lines: 113

Seeing as how I find myself in the unfortunate position of
having to do YET ANOTHER PROJECT.... I figured that I'd do something
that would at least be applicable to my amiga....

Please consider that this is an alpha spec (IE I'm still
screwing around with the idea) but that it IS going to have
to be hammered out within about a week or so into a preliminary
design spec....

I'd appreciate Net comment, Net ideas, Net sample code, Net sympathy etc

I'd  especially like to hear what some of the commodore people
and Matt Dillon think.
(ESP. Matt)

Ok here it is.... as part of a class in hardware design, and software support
of said hardware, I would like to come up with a cheap network for the
amiga. My idea is as follows....

Utilizing the amiga serial port ( yeah, ok, its there, and I don't
have any of the hardware manuals so I don't know how to use the
parallel port as a simultaneous input and output device)
as a relatively high speed output device (I seem to recall hearing over the
net that the amiga can do about 100k bps out the serial port
without a sweat, and about 200k bps with a lot of sweating )
I would like to build a network by tieing the transmit line of each system
to the receive line  of the next system in line, thus forming a
ugly looking ring network.

The hardwrae handshaking would be handled by connecting the
RTS line of the sending system to the CTS line of the receiving system...
The hardware interface would be primitively simple, DB25 connectors
run to the amiga serial port, with two RJ11C 4 wire conectors
on the back, one being the in line, and the other being the out.
Only three wires would be used, the transmit/receive line, the
request/clear to send line and a ground, but I'm trying to use parts that are
in my junk box...

The idea for the software is to create a network device...
called NET:

(now, i've programmed under microsloth dos, and unix, and on my amiga
but i've never programmed a device driver, so if people can mail me
sample device driver source code, like PIPE:, P:, NULL: I'd certainly
appreciate it...)

the idea is that access to the network would be as such,

NET:0/df0:foo/glar/spam

NET is the device name, the 0 is the net  number, and the rest
is the filespec for the remote system.


The actual transmissions would be as follows,

initiate packet.

node number ANDed with 128 (is the idenifier for a initiate packet) is byte 1.
length of packet (filepath/name) is byte 2.
read or write is byte 3
rest of packet is the filepath/name
packet terminator is NULL/001/NULL/001/NULL

error packet is
nodenumber ANDed with 64 (identifier for an error)  byte 1
Packet to resend. byte 2
packet terminator

data packet
node number  byte 1
packet number byte 2
packet length bytes 3 and 4
data packet
two byte checksum
packet terminator

the receiving system would receive the packets, see if its for it, and
if it isn't send it on.


Obviously i'm still fleshing it together....

now for my questions. obviously i have to write a device driver
for this thing. Now, does this device driver have to grab the serial port
directly? or can it talk to SER:

IS THIS THING FEASIBLE OR HAVE I BEEN DRINKING TOO MUCH ROOT BEER??? :-)
(sorry for shouting.... :-)   )

Will Lattice V5.0 be all that I need to accomplish this???

obviously a network watchdog program would be nice as well, obviously
that should be in a window.... can cheapnet.device create error
messaging that another task can catch and  display???

Please send comments, corrections, etc. etc.  to

cronejp@uregina1.bitnet

or if you cannot find this address, use
cronejp@mcl.uucp

and yes, I know that this is an imposition, but i really would like
to write this thing to the point that i can get a mark for
it then, maybe release it as a freely redistributable type of thing

thanks very much....

Jonathan P. Crone

CRONEJP@UREGINA1.BITNET
cronejp@mcl.UUCP