[sdiy] Digital delay memory
ebrombaugh1 at cox.net
Wed Apr 27 20:07:24 CEST 2016
On 04/27/2016 10:57 AM, Richie Burnett wrote:
> Although one is supposed to refresh every location of DRAM at least
> every 16ms, I was once amazed to find intelligible audio playing out of
> the chips after I'd hit a breakpoint in the debugger and the refresh had
> be stopped for a couple of minutes!
That's true - DRAM data becomes unreliable if not refreshed but it
certainly doesn't decay away to nothing. I remember "the good old days"
when cycling power on a DRAM-based video card would still leave
recognizable data visible on power-up.
The rate of data corruption is related to temperature - there are known
computer security issues where hackers load up a machine's memory with
secrets, cool the RAM with freeze-spray and then cut the power.
Rebooting with a compromised OS then allows dumping the contents of the
RAM for analysis without the victim OS and applications being able to
detect the intrusion.
More information about the Synth-diy