DATUs Explained
by telephreak 
telephrk@phonerangers.org
of The Phone Rangers
www.phonerangers.org
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Introduction. 
This is my first real somewhat technical article so please understand
if its not done greatly. As reasources i am using other texts, 
as well as information I've aquired throughout my phreaking life. In this article
i hope to give you a decent idea on what a DATU is and what it can do foryou. I will 
also tell you how to find DATUs in your area.

What a DATU is: 

DATU stands for Direct Access Test Unit. There manufactured by Harris Dracon, and 
are basically a system that allows someone to do different tests on a specified phone 
line. DATUs are accessed by dialing a number, entering a password, entering a phone 
number, and finally entering different touch tones to have them preform tests on the 
specified line. 

How To Find Them: 

Like all test numbers, DATUs are mainly found by scanning. The easy thing with DATUs and 
scanning is almost always the last 4 numbers are 9935. There is about one DATU for every
city, however this doesn't meanone DATU for every prefix. If you live in Elizabeth, and 
the prefixes thereare XXX, YYY, RRR,and TTT (note the letters are suppose to represent 
numbers), then you have to scan XXX-9935, YYY-9935, etc... Get it? Also the easy way to 
do it is get the available prefixes for a NPA, and scan the 2xx-9935 one night, 3xx-9935 
another, and so on, then you'll get all the DATUs for your NPA. Remeber that not all DATUs 
have the 9935 suffix, just alot have it.  

So your scanning XXX-9335  for your npa but you dont know how to tell if you found one or 
not. When you find a DATU you know you've got one. They usually pick up either in the first 
two rings and sometimes in the middle of rings. When they pick up you hear a low, deep tone,
kind of like if you made your voice really low and went 'mmmmmmmmmmmmmmm'. 

Whats Next?: 

You've got a couple DATUs and you don't know what to do with them. When you hear that low
tone, the DATU is telling you to enter in your passcode. Passcodes are usually 4-digits. 
The default passcode is 1111 or 4300 but many time COs change them so you have to do a 
little cracking.  After you enter in your passcode, you will know it works when you hear
another low tone. This lone tone is prompting you to enter in the phone number. You can 
only enter a phone number that is in that town, I don't think it works if your enter in 
a number from a different town. So for example say your still in Elizabeth and the 
prefixes are xxx,yyy,rrr, and ttt. Well those are the only prefixes you can use. You 
can't do a test on SSS, thats in newark. 

So you enter in the phone number, also remeber that you don't have to put the npa in, 
just the prefix and suffix (XXX-XXXX). You can't enter a toll free number, i don't think
they work. 

The Menu:   
After you've entered the passcode, and phone number your either read off the menu, 
sometimes it doesnt do this, so i will post it here. I think I might not have all 
the codes so just fool around with the keypad to find more and if you do email me. 

keypad entry     What it does
1                 Menu.
2                 Audio Monitor
3                 S/C to Ground 
33                S/C to Ground
37                Ring to Ground
38                Tip to Ground
4                 High Level Tone
44                High Level Tone
47                Tone on Ring
48                Tone on Tip
5                 Low Level Tone
6                 Open Line
7                 S/C Line
*                 Keep on After Disconect
#                 New Number to Test

Also not all DATU equipment uses the same keypad options
so you may have to fool around a little.