jtag help

[t160hq]

Pad 1 only has to be grounded when reading
or programming the EEPROM. It also has to
be grounded when programming the TSOP.
Reading the TSOP can be done with pin 1 grounded
or not.

Usually, device unknown is caused by several things.
bad connections anywhere from the receiver to the
port on the computer. Hooked up wrong. Easy to do
when its a DIY unit. It could also be the computer.
It may just not work with a jtag.

Unless you left it hooked up for hours trying it
it's unlikely you damaged the resistors. You can
check them with a multi meter set to ohms. You
can check continuity on the wires as well.

From the way you described your unit if you are
using the same type wire used for hard drives
or floppy drives one wire per connection is plenty.
Even for the ground. Hooking up 4 to 5 wires per
connection is over kill. It also makes it hard to
hook up without shorting something somewhere.

8" is a good length. If it's a total length. Do you have
a cable running from the printer port to the 8" jtag?
How long is it? Is it a true pin for pin DB25. A lot of
special DB25 cables are out there. Many are not
wired pin for pin. Pin 1 to 1 pin 2 to 2... that sort of
thing.

The best advice I can give is double check everything.
Get rid of the multiple wire connections and go for
single wire connections.

t160hq