[AH] Red noize

[The Old Crow]

On Sun, 6 Feb 2000, Magnus Danielson wrote:

> Such an noise source can be built by taking a tap after the 35:th and
> 39:th register and XORing them and feedback that to the input. Have a
> 1 MHz CMOS clock oscillator feed the clock inputs of the chips.
> 
> A little ASCII schematic:
> 
> +-------+
> |       |
> | 1 MHz |--*-------------*------------------*
> |       |  |             |                  |
> +-------+  |             |                  |
>            |   1/2 4517  |   1/2 4015       |   1/2 4015
>            | 4 +-------+ | 9 +-------+      | 1 +-------+
>            *---|CLK    | *---|CLK    | 3    *---|CLK    |       1/4
>              2 |       | 6 7 |    Q3A|---*   15 |       | 11  1 4030
>        GND ----|WE  Q32|-----|DIN    |10 | *----|DIN Q3A|-------\\--\  3
>              7 |       |   6 |    Q4A|---+-* 14 |       |     2 ||   >---*
>            *---|DI     | *---|RESET  |   |  *---|RESET  |  *----//--/    |
>            |   +-------+ |   +-------+   |  |   +-------+  |             |
>            |     GND ----*---------------+--*              |             |
>            |                             *-----------------*             |
>            *-------------------------------------------------------------*
>            |
>            Digital Out
> 
> You have to treat the digital output some. But in general the above curcuit
> will be the full core. I haven't breadboarded it or anything, but it should
> be a simple thing to do once you have the chips around.

  I made a PIC version of a 31-bit FSR noise generator; I'll tweak the
code for your 39-stage version and see how it sounds.

  --Crow

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