From: Humphreys, David (david.humphreys_at_honeywell.com)
Date: Thu Oct 07 2004 - 11:46:32 PDT
> -----Original Message-----
> From: newtontalk-bounce_at_newtontalk.net
> [mailto:newtontalk-bounce_at_newtontalk.net] On Behalf Of Hemant Kamat
> Sent: Thursday, October 07, 2004 1:26 PM
> To: newtontalk_at_newtontalk.net
> Subject: [NTLK] When Memory Fails
>
> Just wondering, LinearFlash cards are known to fail over time
> (for the uninitiated, they have a fixed life expectancy
> measured in terms of 'eraze'
> cycles). Now since, the internal memory in a Newton also
> happens to be Flash, logic dictates that it too should
> exhibit the same tendency to knock off someday :(
Indeed it will - someday! Truth is that the large number of guaranteed cycles coupled with the fact that this applies to
every cell and that very little actually changes unless you have it plugged into a router, not to mention wear-leveling,
means that it will be a long, long time before it fails.
Of course, like anything else, there are always exceptions to the rule. Parts do fail due to nothing more that random
collisions with background radiation. But this is statistically zero.
In short, the memory will last much longer than the Newton as a whole will.
> Anybody have any idea what would be the life time of the
> internal memory of a Newt? Also, what would happen if the
> memory failed? Would the Newton still startup, since the main
> OS is logded in non-erazeable ROM? Are there any signs to
> lookout for in a failing Newt? And, most importantly, can the
> internal Flash memory be replaced?
A failed memory would manifest itself as a write failure rather than a read failure. Depending on which particular
cell(s) were damaged and just what was written there would determine the failure mode. It is quite possible for the
Newton to start up. Until a write to a non-functional cell was tried everything would look normal.
There are so many things that could occur as a result of a failed flash cell that it is hard to say with certainty just
what to look for.
As for replacement, there are two hurdles:
1. The chips are obsolete. The only way to get them is through brokers.
2. They are TSOP56 packages. In English, they are 56 pin IC's with a lead spacing of 0.5mm
> Also, does this apply to CompactFlash cards as well?
This also applies to ANY flash based product.
Regards,
PCBman
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