Definitive Guide and RIS 2.0

Definitive Guide to LEGO MINDSTORMS was originally written for the RIS 1.0 and 1.5 sets. The second edition of the book has been updated for RIS 2.0. However, the first edition can still be used in conjunction with an RIS 2.0 set. This page provides a few tips to keep in mind when using the first edition of Definitive Guide with RIS 2.0.

RIS 2.0

For the most part, RIS 2.0 is the same as RIS 1.5. It uses the same RCX and the set contains the same pieces (plus one new piece). The major differences are that the Infrared tower now uses a USB connection, the RCX's firmware has been updated, and the visual programming environment (RCX Code) has been improved. (These differences are explained in greater detail here)

If you are using a Windows computer that meets the system requirements for the Lego software, then the USB Infrared tower and new RCX firmware should work without a hitch. The only other caveat is that you will need a recent version of NQC or BricxCC (previously known as RcxCC) in order to use the USB tower with NQC programs. If you use another operating system, you should first make sure that the USB tower is supported with the tools you plan on using. Currently, NQC only supports the USB tower under Windows and Mac OS X, although support for Mac OS 9 and Linux may be added soon.

Since RIS 2.0 contains all of the pieces in RIS 1.5, the projects can all be built according to the instructions in the book. In the cases where supplementary pieces were necessary with 1.5, those same pieces will be necessary with RIS 2.0.

Although NQC has become a lot more powerful over the past two years, the programs in the book will still compile with the latest version of NQC. While you won't have learned about every single feature of NQC, you should be well versed on the fundamentals by the time you finish the book.

RCX Code

RCX Code has been completely overhauled for RIS 2.0. New features have been added, and the old ones have been given a facelift or rearranged. Because the illustrations in the book were based on the RIS 1.5 software, they will look a bit different from what you see on screen when using 2.0. The picture on the left shows a simple bumper car program written for RIS 1.5, while the right side shows the same program in RIS 2.0.

Most of the differences are superficial - rectangular pieces instead of curved ones, changes in capitalization, etc. However, there are also a few significant modification. The "set direction" block can only work with one motor in RIS 2.0, so the block that reversed motors A and C had to be converted to two separate blocks in 2.0.

The next example is an RIS 1.5 program that is a bit more complicated. The sensor watcher handles two different conditions (dark and bright), and in one of the cases makes a further decision based on a "check and choose" block.

RIS 2.0 only supports a single condition per sensor watcher, so the single light sensor watcher in RIS 1.5 was converted to two separate sensor watchers in RIS 2.0. The "check and choose" block is also now known as an "if" block. The RIS 2.0 version of this program appears below.

These changes may seem a bit confusing at first, but after a few programs you'll get the hang of it. In the meantime, let RIS do all of the work for you. Download the programs from When you open these programs in RIS 2.0, it will automatically convert them to the new 2.0 blocks and make any necessary changes.

Just the Beginning

RIS 2.0 is a bit more powerful than its predecessors. In the case of RCX Code, many of the limitations cited in the book are no longer a probelm in 2.0. In addition, there are several new features of 2.0 which are not covered in the book. The same thing is true for NQC, although many of the new firmware features were covered in my second Mindstorms book, Extreme Mindstorms.

In any event, Definitive Guide was always intended as the first chapter of an adventure with MINDSTORMS. With RIS 2.0, that adventure just got a little bigger.