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Luis Villa <liv@duke.edu> wrote:
> I'm most of the way to getting it working myself, but I was curious to
> see if anyone has implemented a random number generator in their bot.
> Anyone? Anyone?
The firmware supports random numbers using some method that whose name I
can't remember at the moment. Something about feedback. Anyways, the
algorithm there boils down to:
int seed;
int
rand (void)
{
char bit;
bit = (seed & (1 << 1)) >> 1;
bit ^= (seed & (1 << 4)) >> 5;
bit ^= (seed & (1 << 6)) >> 6;
bit ^= (seed & (1 << 9)) >> 9;
seed = (seed << 1) | bit;
return seed;
}
This can be implemented in asm very succinctly. Something like:
int seed;
extern int rand (void);
__asm__ ("
.section .text
.global _rand
_rand:
mov.w @_seed,r0
bld #1,r0l
bxor #4,r0l
bxor #6,r0l
bxor #9,r0l
rotxl.b r0l
rotxl.b r0h
mov.w r0,@_seed
rts
");
... but really, I haven't tested that, and don't even know if it will
compile.
-Kekoa
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Message has 1 Reply:
 | | application termination
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| Hi, what is the magic in LegOS to quit the application so that it can be restarted again? In some demos it works, but the same mechanism (i.e. 1 stopper process that kills the other on [run] button) quits the program, but the display says some (...) (25 years ago, 16-Jul-99, to lugnet.robotics.rcx.legos)
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Message is in Reply To:
| | random numbers
|
| I'm most of the way to getting it working myself, but I was curious to see if anyone has implemented a random number generator in their bot. Anyone? Anyone? -Luis ###...### Profanity is the one language that all programmers understand. -Anonymous (...) (25 years ago, 13-Jul-99, to lugnet.robotics.rcx.legos)
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