[cctalk] Re: Computer Museum uses GreaseWeazle to help exonerate Maryland Man

[Paul Koning via cctalk]

> On Feb 1, 2023, at 3:20 PM, Fred Cisin via cctalk <cctalk@classiccmp.org> 
> wrote:
> 
> On Wed, 1 Feb 2023, Ali via cctalk wrote:
>> But does that matter? If the main purpose is to be able to refresh the data 
>> so it is readable does it matter that the data is not in the same block as 
>> long as it is readable?
> 
> Ah, but most of that sort of memory has a finite number of cycles, and wears 
> out due to use.
> Testing it is heavy usage, and brings about an even earlier end of life.
> Could we call that a "nosocomial" ("not so comical") deterioratoin :-?

It's well known that flash memory (and NVRAM generally) has write limits.  I 
don't know of any read limits.  Some other memories have write limits as well 
though they are far larger and generally far less known.  I think some of the 
phase change non-volatile memory types that seem to emerge from time to time -- 
FRAM for example -- have write limits.  Modern high density HDAs also do, I 
believe, because the heads actually come closer to the surface during write and 
as a result are more likely to touch the platter.

But read limits?  I'm not sure about that.  What sort of numbers are we talking 
about?

If all else fails there's core memory, which as far as I remember is pretty 
much unlimited for both read and write.

        paul