Korg Poly800/EX800 Users

Here's my pseudo random number generator.

It is by no means very random.

; my pseudo random number generator - used for the LFO randomiser
; returns a random number in A

RANDOMIZE:	push	h ; save HL
		lxi	h, M_RANDOM ; point at the previous value (seed)
		mov	a, m ; put the seed value into A
		cpi	0 ; check for seed equals zero
		jnz	RANDOMIZEA ; if seed is zero jump to randomizea
		cma ; compliment A
		mov	m, a ; put A back into seed
RANDOMIZEA:	rlc ; rotate left through carry
		adi	43 ; add 43 offset
		mov	m, a ; save in seed
		pop	h ; load HL
		ret ; return with pseudo random in A

I would be more than happy for you to suggest something better as long
as it doesn't add any CPU cycles. :-)

Mike



--- In korgpolyex@yahoogroups.com, Atom Smasher <atom@...> wrote:
>
> On Wed, 17 Sep 2008, korgpolyex800 wrote:
> 
> > I knew someone would eventually suggest over clocking the CPU.
> ===============
> 
> i didn't mean to imply that. i'm not eager to cook anything in my old 
> gear.
> 
> 
> > The only problem with that is that those old CPU's had a maximum
clock 
> > rate that really was the maximum clock rate. And that is the
principle 
> > that applies to the old 80C85.
> =================
> 
> maximum clock rate is, too a point, a function of temperature. but
no, i 
> don't want to have a liquid nitrogen cooled EX800.
> 
> 
> > Look up tables are used for the sine wave. But I found that the fast 
> > code for triangle, saw, random and PWM was to use real code.
> ==================
> 
> i would still think that it would be feasible to use a distorted
wave in a 
> lookup table and get "ohmygod" fast LFOs, without burdening the
CPU... but 
> i'll take your word for it if that's not the case.
> 
> as a crypto geek, i'm still curious how you're calculating the random 
> wave, and what the period is.
> 
> 
> -- 
>          ...atom
> 
>   ________________________
>   http://atom.smasher.org/
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