[sdiy] Bubble memory analog delay?

[cheater00 .]

Hi Richie,
thanks for your email. You got me thinking about how to use RAM in fun ways.

On Tue, Jul 9, 2013 at 5:04 PM,  <rburnett at richieburnett.co.uk> wrote:
>> I'm sure just like with tape drives not only "0" and "1" could be
>> stored but any voltage inbetween.
>
>
> It's an interesting idea, but I think these types of memory rely on fully
> flipping the magnetic domains in order for the states to properly propagate
> down the line.  "Intermediate" states probably woudln't propagate because
> the delay-line is not a linear device.

What is "fully flipped", though? There's domains of specific
directions of magnetization, but there are more than two directions in
a 2d substrate anyways. Note - magnetic tape domains don't reflect the
signal they represent in their degree of magnetization, either. The
domains are created artificially with the bias oscillator.

> Much better to use modern DRAM
> derivatives for digital audio delays in my opinion.

How do you mean? Just DAC -> DRAM -> ADC? Something like that? Would
you want to somehow modulate the clock at which the ADC and DAC work?
Perhaps SRAM is a better choice in that case.

Speaking of which, I was wondering if there was something like a 2D
CCD where you could move the image either horizontally or vertically.
I wonder if one could possibly implement simple convolution with such
an item.

Cheers,
D.