DLR-3/DLR-3P

Personal photos of the NEW cable I bought

Scheme (from nobbi.com):

The main cable for connecting 6210/7110/6310(i) phones, and their modifications like 6250. It is known about their production in Slovakia and Thailand. It differs from DAU-9P by the presence of a PIC microcontroller that allows using a phone AT-modem and connecting to original software. As well as the method of obtaining power for microcircuits: when contacts 3 (MICIN) and 9 (GND) are connected through a 15kΩ resistor, the phone switches to DLR-3 mode and contact 4 (AGND) becomes a voltage source 3.3 V, from which the cable is powered. On the one hand, there is now no dependence on the voltage level of the COM port of the computer, on the other hand, the operating time of the phone is reduced due to the power from it to microcircuits, and also, obviously, it does not work with the previous generation of phones that do not know anything about the DLR-3 mode.

Since the contents of the microcontroller cannot be read, a 100% clone was never made. However, Adrian Dabrowski managed to develop a fairly close copy of the cable (two versions, a third was planned). His website (www.atrox.at) was taken down in ~2011, so the information on this cable is stored on my server. Read more HERE.

At the moment (October 2022) the average price of a new cable on online trading platforms is about 30 $.
Which, however, is a rather high price, but used cables can be found on average for tolerable 18 $.

DAU-9/DAU-9P

Photos from the Internet (I will replace my own when I get one)

Scheme

Cable for connecting phones 5110/6110/6150 and the like. However, it can be limited used with 6210/7110/6310(i) and similar phones. The limitation is that AT-modem is not supported, and Nokia PC Suite will not work through this cable, but you can use alternatives like Oxygen Phone Manager and LogoManager that can work through it. In fact, it is a voltage level converter on the MAX3232 chip, so it is easy to assemble (the scarce element here is, perhaps, the phone connector). Probably only made in Thailand. Could be sold together with Nokia Data Suite.

!!!WARNING!!!: DAU-9P is powered by RS-232 port, and requires at least 7,7 V for the circut to work. This is not true for most Notebooks and USB-COM controllers, since their signals are 5,5 - 6,5 V in most cases, so DAU-9P may not work! In this situation you can use DAU-9P Notebook Edition by Adrian Dabrowski (atrox).

This cable, due to its simplicity, is much cheaper - on average, you can find it for 12 $.