"The transmission medium of Chaosnet is called the ether. Physically it is a coaxial cable, of the semi-rigid 1/2 inch low-loss type used for cable TV, with 75-ohm termination at both ends. At each network node a cable transceiver is attached to the cable. A 10-meter flat cable connects the transceiver to an interface which is attached to a computer’s I/O bus."
[...]
"The transceiver receives a differential digital signal from the computer interface and impresses it onto the cable as a level of about 8 volts for a 1, or 0 volts (open circuit) for a 0, through a very fast VMOS power FET. When the cable is idle it is held at 0 volts by the terminations. This simple-minded unipolar scheme is adequate for the medium cable lengths and transmission speeds we are using. The transceiver monitors the cable by comparing it against a reference voltage, and returns a differential signal to the interface. In addition, it detects interference (another transceiver transmitting at the same time as this one) and informs the interface."
Seems like the above would be all that's necessary for the simplest possible "built around first principles" local LAN, if someone wanted to experiment with an early Ethernet-like system...
Related. Others?
A Short History of Chaosnet (2018) - https://news.ycombinator.com/item?id=36079416 - May 2023 (5 comments)
A Short History of Chaosnet - https://news.ycombinator.com/item?id=29927718 - Jan 2022 (1 comment)
Chaosnet Network Protocol - https://news.ycombinator.com/item?id=20972236 - Sept 2019 (11 comments)
Chaosnet - https://news.ycombinator.com/item?id=19623831 - April 2019 (12 comments)
A Short History of Chaosnet (2018) - https://news.ycombinator.com/item?id=19480577 - March 2019 (6 comments)
Short History of Chaosnet - https://news.ycombinator.com/item?id=18107136 - Sept 2018 (5 comments)
Chaosnet, a memo from July 1981 - https://news.ycombinator.com/item?id=6787665 - Nov 2013 (1 comment)
Chaosnet in active use, mostly on emulators: https://chaosnet.net/
Lispm, PDP-10, PDP-11, VAX.
Is this the same CHAOS that can be in IP packets as protocol 0x10?
Yes, and in DNS messages as class 3.
Yes, and in Ethernet frames as EtherType 0x0804.
Get your public IP from cloudflare over chaos dns: dig @1.1.1.1 ch txt whoami.cloudflare +short
As a reminder, CHAOS protocol is valid over IPv6 as well.
Should not be confused with Chaos VPN, a predecessor to dn42 for linking nstworks of the Chaos Computer Club.
Woaw! You could use a space cadet keyboard with this!!1!
I only know of this because the CADR emulator supports an emulated version of it.
It is also capable of doing it over the wire.
"The transmission medium of Chaosnet is called the ether. Physically it is a coaxial cable, of the semi-rigid 1/2 inch low-loss type used for cable TV, with 75-ohm termination at both ends. At each network node a cable transceiver is attached to the cable. A 10-meter flat cable connects the transceiver to an interface which is attached to a computer’s I/O bus."
[...]
"The transceiver receives a differential digital signal from the computer interface and impresses it onto the cable as a level of about 8 volts for a 1, or 0 volts (open circuit) for a 0, through a very fast VMOS power FET. When the cable is idle it is held at 0 volts by the terminations. This simple-minded unipolar scheme is adequate for the medium cable lengths and transmission speeds we are using. The transceiver monitors the cable by comparing it against a reference voltage, and returns a differential signal to the interface. In addition, it detects interference (another transceiver transmitting at the same time as this one) and informs the interface."
Seems like the above would be all that's necessary for the simplest possible "built around first principles" local LAN, if someone wanted to experiment with an early Ethernet-like system...
Anyway, great article!