Does anyone have any documentation on this device?
The phone number on the sticker is no longer in service,
and I cannot find a listing for National Electronics SSD.

<als>

See if http://www.capturecctv.com/ has what you are after, they have a very similar model no (cptcd9t) on the site, and all manuals/spec sheets are available for download.

If the exact model is not there, then a similar model may be similar enough to figure out most features from the manual, or you could email and see if they have the exact manual if its not listed.

Here is their website ...
http://www.capturecctv.com

this maybe the specs for that mux:
http://www.capturecctv.com/files/pdf/cpt-cd4t-9t-16t.pdf

and the manual:
http://www.capturecctv.com/product.php?prod_id=59

Rory

PS. welcome to the forum ..

Thanks for the pointer. The logo is the same, but the company is
based in Canada. Apparently, the name on the label was a
distributor.
The model number is the same except for the added "T", and is
apparently similar, but not identical. Plus, there was no manual
listed.
<als>

I would give them a call .. they are a canadian (and Korean) company but their products are used or were used in the US.

I had a similar issue with their PC Based DVR a couple years back..
http://www.cctvforum.com/viewtopic.php?t=1191&highlight=capture

I have to admit that I am impressed by the response from these folks.
Manual was emailed with no argument or hassle (although it is the
manual for the B/W version, all I needed was pinouts for the alarm port).
If their products are as good as their attitude, I would have to
recommend them.
<als>