Yes the chips do have this but as an 8 bit instruction. You can use assembler or you can do it by hand by using shift. Copy the most significant bit before the shift, do the shift and then if the most significant bit was one set the least significant bit.
Just be careful that the above code is dependent on the sequence of evaluation and you may need to break it down into two statements to avoid that problem.
That the rotate instructions are only 8 bits is exactly what I'm looking for.
What I'm trying to do is a 16 bit psuedo random number generator.
Two 8 bit shift registers, conected together, with an EOR gate.
The 2 inputs of the EOR gate are conected to the outputs of the shift registers, the output of the EOR gate is conected to the input of the first shift register.
I'd draw a circuit, but it doesn't look like I can post anything from a mobile!
Anyway, if you use the bit 15 output to drive a speaker and change the clock rate, you can make a passible engine noise generator.
If you want to get trickier, use an AND gate, take your white noise generator output and a tone to get other effects.