Which software do you have ? You can download 3.0R20 from the Ritron web site.
First you need to know which processor your radio has ( R1/03 or R1/04)
I would try reading as an 03 first, and if you can't read it, try as anR1/04.
If you still can't read it, then you REALLY need to figure out which processor you have.
From the second page of the program type "M", on the next menu do a "2"
to try and determine the micro version.,
if you still read it, go to "m" "1" and load with factory default ( be VERY careful)
as you could BRICK the radio, and you would have send it back to the factory,
which is likely to cost more then you paid for the radio.
Once you load defaults, try reading it again ( with a "1" on the second page.).
try to read it two or three times.
Now you know about as much as I do about that portable.
not a bad radio, but a little big by today's standards.
There are a couple really cheap uhf portables on that "E" place,
I got one , including software and cable for $40 shipped.
careful and find the one WITH software and cable.
Best of luck,