Aaron J Reichow wrote:

On Mon, 24 Apr 2000, Jay Casler wrote:

[clipped]

There are options available (with work) for Squeaking on an RCX:

1. Have Squeak generate NQC code (easier)
2. Use source from the NQC base to create primitives for comunicating

with and compiling bytecodes for the RCX.

Documentation of the RCX bytecodes ( and a lot of other RCX info) can be found at: htt://graphics.stanford.EDU/~kekoa/rcx/index.html

What about having methods that generate properly formatted byte streams for each opcode and then building successively more complex levels of functions from these methods (or is this the same as #2 above)? Once you do this I would think you could derive subclasses that would either control the RCS in realtime or create and download programs. No need for SPIRIT.OCX. Totally portable.

There is also a lso C source for a utility to communicate with the RCX through the IR tower (send.c). Its about 210 lines of code not counting comments and empty lines. Can Squeak use procedures in an external library? If so this would save a fair amount of work.

[clipped]

I also believe that NQC can communicate with the RCX in real time.

I looked over the html docs for NQC and I didn't see any mention of this. Perhaps I wasn't looking in the right place.

I think employing this could be a much more viable option. Even better, a Squeak-NQC bridge could use the same API as the BotKit, perhaps a superset of it, so programs written on one system (BotKit on Dolphin/Win32) could be ported to another (RoboSqueak on Squeak/*).

Once you can get the basic opcodes I don't see why you couldn't recreate the Dolphin API. I've started writing methods but before I can go much farther there are some basic questions that I need to answer.

1. Exactly how is immediant execution of commands different from downloading and executing programs from the RCX's viewpoint? 2. In immediant mode many of the command opcodes return values signifying success. In stored programs these return codes are ignored. In terms of class hierarchy how should this be handled? Different classes for stored and immediant mode or a single class with a state variable and some conditional code? 3. How should error recovery be handled? kick into debugger? log to file and continue? 4. At what level should the opcodes be checked for validity? In the lowest methods or higher up? Actuall I would think at the lowest levels. 5. Will Wiley Coyote ever catch the Roadrunner?

Aaron

As I am sure you have already guessed, I am new to smalltalk and this OOP thing. Any comments are welcomed.

Thanks

Dana

-- Dana S. Wheeler dwheeler@gte.net

Maintain a humble awe in all things of God and a cynical skepticism in all things of man.