18 Oct
2013
18 Oct
'13
9:10 p.m.
On Fri, Oct 18, 2013 at 10:40 PM, Richard <legalize at xmission.com> wrote:
As usual with equipment of this age, check capacitors
and check the
power supply.
Everything else with the terminal works. Local mode works great. Half
duplex on the terminal works fine too, but it can't receive anything from
the serial port. And for the life of me, I can't seem to determine where
the output of the 1489 goes besides to pin 20 of the DB-25 connector. I
also made a loopback adapter, connecting pins 2 with 3 and 4 with 5. Still
doesn't work! I'm seeing a nice asserted/deasserted levels too with my
'scope on pins 2 and 3, but pins 4 and 5 almost look like they are driven
from a capacitor, as the voltage swing starts off a
little high and
gradually works its way down to nothing.
Kyle