HELP! Just got one of these 1994s based on the WEALTH
of info on this site (RS should be funding you). I'm
in a bind because the code for Zenith DVD 0503 doesn't
seem to have ANY effect on my Zenith DVD. Both of
the provide codes for H/K don't do anything for my
H/K AVR300 either. I set out to "learn" all of the
codes but soon ran out of mem.

I have seen the comments about all the things you can
do with this remote but it seems to me that if you have
2 devices that are NOT in ROM, there are too many
buttons to learn.

The hackbox looks interesting and I would not be
opposed to building it, but for all the info I've
seen on it and that it allows me to reconfigure the
remote, I am still not clear on what that will gain me?

Any thoughts?

have you tried the advanced codes @ Hifi-remote.com ?

Here's what you could do with a JP1 box:
Learn a few buttons from your DVD's remote into the 15-1994. Dump the memory. Analyze the learned code. Extract the protocol and device code from the learning memory, and the function codes for each button (iteratively). Create an upgrade code for your device, assigning the functions you want on the buttons your want. Download this to your remote.

Voila - Your DVD is supported and no learning memory is used.

The process I described is not that difficult with the software and spreadsheets that are available.

Your Zenith DVD shares the 0503 code with Toshiba DVD's. I wonder how closely related they are. My Toshiba DVD uses this code and it works great.