24 Oct
2012
24 Oct
'12
6:08 p.m.
On Thu, 25 Oct 2012, Pete Turnbull wrote:
On 24/10/2012 22:57, Philip Pemberton wrote:
Not so fast. DEC was already doing this with 6P6C MMJ cables with a nearly
identical system before Dave Yost came up with his standard using 8P8C
adapters and cables. The additional two wires available with the 8P8C
connectors allows for RTS/CTS.
http://en.wikipedia.org/wiki/Serial_port#Pinouts
Apparently Cisco isn't /strictly/ Yost either but it looks like Cisco has
tried to standardize on it.
http://yost.com/computers/RJ45-serial/
http://www.cisco.com/en/US/products/hw/routers/ps332/products_tech_note0918…
Still, some of the first 8P8C connectors I remember seeing used with
serial devices were with Cyclades and Digi multi-port serial interfaces.
While the Yost system is more flexible, the systems Cyclades and Digi used
do have more signals available (including RI with Digi's, which could
generally be swapped via software from pin 1 on the 10P10C connector to
one of the pins that would be available to an 8P8C connector). Yost's
system wouldn't be too good for a bank of dialup modems, but Digi's system
was widely used for this.
Nope - your memory is fine. I'm sitting next
to a Catalyst 2970G which
has the aforementioned RJ45 console port.
To connect it to a PC you use either a "rollover" cable and adapter or
a Cisco console cable - basically the same thing but without a
detachable rollover cable (a piece of 8-core flat cable is crimped onto
an 8P8C RJ45 then attached to a moulded-on DE9F connector).
Look up "Yost" if you want to know where Cisco stole that idea from.