There are only two ways to rip your DC games:
Using a broadband adapter and transfer the disc's data to your computer via internet. You don't want to use the default line connection, it'll go at 40k/sec and it'll make your Dreamcast work for way too long (24h a game compared to 20 minutes with the BBA.).
-You'll have to use a program httpd-ack (
Click here to download) and burn the CDI file on a CD-ROM
-You'll need an official (or burned CD) version a DC Web Browser to configure your DC's static IP. XDP recommended, this is the one I used and I didn't had any problems.
-You'll need CDMage as well to verify if you data are correct. (Click here to download)
Click here for the complete tutorial for the Broadband adapter method.
You will also be able to get the DC_BOOT and DC_FLASH files you need to run NullDC with the BBA method. These are available to take from your console each time you're ripping a game.
There is also the SD card ripping method, with which you will need an SD card adapter that will go in the back of the dreamcast.
You can easily find those on Ebay for 10 times cheaper than the BBA.