Dear RCX owner

We are proud to launch the new RCX 2.0 Beta SDK. Included in this SDK is a new firmware for the RCX. This firmware will be used in the new Vision Command product from LEGO MINDSTORMS that will be launched on a global scale in September 2000. 

The RCX 2.0 Beta SDK contains many new things in the LEGO MINDSTORMS universe. The contents have progressed significantly since we published the RCX 2.0 Pre-Alpha SDK. Aided by your feedback, we now have a stable and (we believe) bugfree and much enhanced firmware. 

Since we made a few small changes and additions to the firmware after we published the last pre-alpha patch (#4), we thought you should have the opportunity to work with the next official RCX firmware *now*. In addition we would like to direct your attention to our high-level programming language called MindScript (called LEGO Script in the earlier releases).


New powerful features in the RCX 2.0 Beta SDK:

1) The main item is a new and much enhanced firmware for the RCX. You can look at the technical details in the "LASM Byte codes" document. We have tried very hard to ensure backwards compatibility while still being able to put in powerful new features, some of which will be recognisable from the Scout brick from the LEGO MINDSTORMS Robotics Discovery Set.

2) The MindScript programming language. MindScript is going to be the ASCII text based program format that the forthcoming LEGO MINDSTORMS Robotics Invention System 2.0 uses for the graphical RCX Code programs. This means that you can create RCX Code programs and then examine the resulting MindScript programs and experiment with them.

3) Support for the Scout from LEGO MINDSTORMS Robotics Discovery Set - both in LASM and MindScript.

The main programming interface is the ATLClient.exe program that supports both LASM and MindScript (and now also both the Scout and the RCX).


The most noticeable new features in the new RCX 2.0 firmware (version 03.28) are:

1) Event monitoring on physical and a number of virtual sensors (timers, IR message and counter variables).

2) Priority based access control to shared resources.

3) Task local variables for e.g. safe parameter passing to subroutines that execute within the environment of the calling task.

4) Global motor and sound control.

5) Being able to play tones with the frequency taken from a variable.

6) The ability to display and track the value of internal RCX data with or without the program running. Great for demonstrating or debugging.

7) The ability to, under program control, switch to another program slot and start it running - just as you can with the LEGO MINDSTORMS Remote Control Unit.

8) Simple support for data arrays/variable pointers.

and probably quite a few more that we forgot in all the excitement.


To download the new firmware, you can either use the option in ATLClient.exe or you can use the command-line program firmware.exe, that downloads and unlocks (any) firmware from a Motorola S-Record file.


The new firmware can be programmed in a number of ways:

1) You can continue to use SPIRIT.OCX and the Robotics Invention System application because of the backwards compatibility. But then you cannot explore the new stuff.

2) Also because of backwards compatibility, you should (!) be able to continue using the 3rd party tools available from the WWW, that uses the standard firmware. We haven't checked, though.

3) LASM programs (LEGO Assembly). You can download and look at the Scout SDK for general LASM guidelines, but check the "LASM Byte codes.pdf" documentation for the commands and syntax available for the RCX 2.0.

4) MindScript programs. The syntax is explained in the supplied VPB.hlp Windows Help File that also supplies context sensitive help to the ATLClient.exe application via the F1 button.


On behalf of the LEGO MINDSTORMS development team

Best regards. Play well & Have fun

July 2000, The LEGO Company