Hi everybody!
In a fair I've seen a system based on Mikrotik routerboard 133 working with two radios at 5 GHz.
In that system I enter through WinBox and I can configure every routerboard as:
- point to point link in bridge mode (only two radios)
- point to multipoint link in bridge mode (one master radio and more slave ones)
- point to point in bridge mode / wds station mode
- point to multipoint dynamic mode
(these are just some configurations)
If I correctly understand the routerboard has got only a bootloader "BIOS" to load the RouterOS operating system which I have to pay a license.
What can I do with RouterOS?
Is it the only OS I can use with the routerboard?
If I need to use a routerboard as a wireless repeater (using the two radio slots) or a point to point, or a multipoint configuration, do I need only RouterOS or something else?
I'm a lot confused!
Thanks in advance for help!

P.S.
I have a R52 MiniPCI radio card, instead buying a routerboard, which Router Board 11 IA should I buy to use the radio mudule in my PC?

Routerboard comes with pre-installed Router OS.

If you have RB133 as a Base Station, you can have a Three MiniPCI wireless Card and you can have three different p-p link in it.

Just you need 3 miniPCI cards

ASHISH.

What can I do with RouterOS?

please read this link:
http://www.mikrotik.com/testdocs/ros/2.9/

there you can find out what you can do with RouterOS (you can do a lot, close to everything you need to do with networking, plus some more extras) and it is easy to configure.

if you buy RouterBoard - it comes with RouterOS preinstalled for you and ready for configuration and use. Usually wireless modules are not included with RouterBoard, so you have to contact reseller you want to buy Routerboard from for details what will come in the package and what you should buy additionally for your scenario of use.

New questions:
which differences between power over data lines and POE?
I know I use POE when I use 4 free pins of ethernet cable to power the radio, but in power over data lines I do the same on data lines?

How can I save a full configuration as file on my PC to make a clone of a radio if an hardware problem occours and I have to change the radio with a virgin one?

Routerboard comes with pre-installed Router OS.

If you have RB133 as a Base Station, you can have a Three MiniPCI wireless Card and you can have three different p-p link in it.

Just you need 3 miniPCI cards

ASHISH.

hiii ashish i m an indian and i need to know more abt mikrotik..if u dont mind can u plz keep in touch wid me my email id is faraz_innocent_heart@yahoo.com..i need ur help to hav a better use of mikrotik..thxxx

I have a R52 MiniPCI radio card, instead buying a routerboard, which Router Board 11 IA should I buy to use the radio mudule in my PC?

Yep! and you can do so for free with RouterOS within a limited time.
Take your time in the manual, welcome to a whole new roooting world.
Tik, Tik, Tik ....

oh, any mini-pci adapter will work, see the RB11 @ routerboard.com
and if your PC supports bootable USB, then you may use a flash drive
http://wiki.mikrotik.com/ for more.