[vcf-midatlantic] Idea for an Exhibit - Novell

Neil Cherry ncherry at linuxha.com
Fri May 25 19:36:57 EDT 2018


On 05/25/2018 06:39 PM, Herb Johnson via vcf-midatlantic wrote:
> Itg's unlikely that a modern Ethernet or WiFi device, could perform the hardware and 
> software protocols corresponding to even older networking standards, including Appletalk. 
> I think such emulators would have to be built from the ground up. They are likely painful 
> to build reliably and flexibly. Remember my concept - sufficient to "echo", handshake some 
> packets - not a full emulation.
> 
> That said, I happen to know, AppleTalk did run "over Ethernet", through simple devices 
> that physically routed AppleTalk traffic on the Ethernet wires. But the Ethernet devices 
> themselves, ignored that "traffic" - probably saw it as bad packets, noise, etc. This was 
> done to put Apple printers on Ethernet networks - except of course any Ethernet-owning 
> device had zero access to Apple printers, and Apple computers had zero access to Ethernet 
> devices.
> 
> People who buy Appletalk printer to Ethernet devices, thinking they are their magic road 
> to "internet their Macs", find out eventually that won't happen.
> 
> So it may be possible, for a few network protocols to share the same cable. But they would 
> not be "interoperative" - that calls for hard work. Companies and careers were made, doing 
> such things in the era. We poor hobbyists live in the shadows of such giants. The amazing 
> thing, would be to get some ancient networking protocol to work AT ALL. I suggest 
> humility, and avoid the simple notion "I can plug it in - so it will work, or could".

I want to throw out a caveat here. My 8 bits days were not networked other than a modem.
When I got into networking in the late 80's there were lots to chose from. This was the
era of the PC so most of my background comes from getting PCs to talk to other things
like Mini's and mainframes.

Ah now you're in my wheelhouse (well kind of). I still have a Cisco router that can speak
most of these protocols. I think Dave was interested in these devices (the CGS and the
ACS). As Herb noted Appletalk could be bridged to Ethertalk but didn't talk to TCP/IP.
This was taking the data layer (?) protocol and changing layer 1 (ISO state).

Other methods of networking were RS485 (full duplex and half duplex). I'm not sure many
microcomputers used this or other networking protocols but I know a few business
microcomputers did (Digicomp? Digi something?). I know Atari attempted to use their
SIO (Serial I/O) bus to do a star. I know that my Circuit Cellar HCS II used RS485
half duplex (master/slave).

I recall an IBM PC with a 3Com card in it (I think the card had a 68000 processor
on it). The PC ran at 4.77 MHz and the 68K ran at 8MHz. I think the network protocol
was TCP/IP.

As herb said getting the protocols to talk to each other is a parin. Get the layer
one to work together was no bad as long as you stuck to 802.3 (thin, thick, or
10BaseT). You could probably get 100baseT and above to work but performace
could get interesting.

For many of us from the 8 bit era, the modem and a BBS was the general method
of networking followed by sneaker-net. Or:

Never underestimate the bandwidth of a station wagon full of tapes hurtling down
the highway. (Andrew S. Tanenbaum paraphrasing Dr. Warren Jackson)

-- 
Linux Home Automation         Neil Cherry       ncherry at linuxha.com
http://www.linuxha.com/                         Main site
http://linuxha.blogspot.com/                    My HA Blog
Author of:    	Linux Smart Homes For Dummies



More information about the vcf-midatlantic mailing list