It's an interesting idea.  You'd have to tristate the memory bus while
accessing the memory with the A/D circuitry.

I don't think it would be any hard or easier to create a PCI card that
does DMA transfers, though, and that would certianly be more flexible.

The IDE interface is well known, you might consider emulating that
instead, and it also requires fewer OS hacks.

If dual port DRAM were available it would be even easier to implement
your idea.

-Adam

Roland wrote:

>Hi
>
>after the recent discussion on scopes, bitscope et al, I looked at Analog
>Device's A/D flash converters, like the AD9283. 100MSPS, just add clock and
>read data, all for about $5.
>
>What I thought of, on which I found nothing on the net, is to make a pcb in
>the format of a simm/dimm module, with the AD9283 memory mapped over say,
>10meg. Then from an uninterruted routing, just 'read' the memory, and copy
>to another location, and then go on to process the data.
>
>The main advantage is it's direct access, and it runs at your memory speed.
>
>So what I'm mostly wondering is if this will work considering;
>- mem test errors on bootup, although it could be made to parallel 'real
>memory' and the A/D only be enabled when required.
>- parity errors on bootup (same above)
>- whether memory is read/written in staggered bursts
>- whether apps like windows can be made to 'keep out' of certain memory blocks
>
>Can anyone say if it's NOT workable? I'm not that up to date on pentium
>architecture.
>
>Regards
>Roland Jollivet
>
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