25 Aug
2010
25 Aug
'10
4:34 p.m.
On Wed, 25 Aug 2010, Eric Smith wrote:
I think the way that I would state it is that just
because the system is
working correctly (at the moment) doesn't mean that it isn't broken.
Part of the reason I don't think we'd fix such a problem in the PDP-1 is
that the PDP-1 isn't doing anything criticial. We can afford to have
downtime if a latent problem eventual causes a failure. If we've
properly documented that latent problem, we can check for it when the
system does fail, and fix it if necessary at that time.
Your ability to tolerate downtime is significant, as also is your thorough
documentation, so that the repair won't end up in the hands of board
swappers.
Y'know, it would be fun to see an entire set of exhibits explicitly about
failure modes. Remember the HUH S100 boards for the TRS80, where one of
the entire early production runs was reversed, but could be used by
soldering all of the components to the back side of the board?
--
Grumpy Ol' Fred cisin at xenosoft.com