Re: Fun with RJ-45!
My favourite was the even-more-unwieldy-than-Ethernet-AUI-cables and the clumsy connectors with the "guaranteed to fail" bypass switches built in. I often wonder if IBM wanted to see just how much inconvenience their TR users would put up with.
I will grant that Token Ring, with all IBM components, did actually work. But, as soon as it got uppity, trying to use UTP like 10BASE-T, Bad Things began to happen. The low jitter requirement (and its consequent sharp voltage transitions) wreaked havoc at EMC testing time, and while 4 megabit TR could, with some effort, be called compliant, getting 16 meg UTP TR switches to run reliably AND pass EMC testing often called for a case of beer to be delivered to the EMC test technician, and his attention directed elsewhere as the system scanned through certain frequencies.
When 100BASE-T arrived, TR died a quick death, and was not mourned. The cost for a 4/16 TR interface card, IIRC was about 3x that of an Ethernet UTP card. Some of that was due to licensing required by TR and not by Ethernet, but the TR MAC also relied on downloaded firmware, while the Ethernet MAC had a much simpler state machine built into the chips.
I developed a low cost TR 4/16 interface card for Data General's AViiON workstations, and some TR switches for 3Com, but I prefer to pretend the entire experience never happened.
Biting the hand that feeds IT
