cctalk Digest, Vol 34, Issue 8

Mark Tapley wrote: There were significant problems with drive dust inhalation in the NeXT implementation. That led to reversal of the fan (by mechanically reversing, *not* by changing around the power connector, in case you want to try it) by many owners, which was eventually approved by NeXT. However, my cube has a fairly unique set-up which meant that fan reversal caused problems with overheating of the SCSI driver chip. There were also long-term problems with either the drives or the media - they seem to be going bad at a fairly regular pace. I don't know that I've heard a good explanation for that. It *might* be some form of connector corrosion; disassembling and cleaning mine has cured it twice, even though it didn't look dirty at all around the lens area. Corrections or clarifications welcome, apologies if this is redundant (getting behind on the digests again). -- - Mark Billy: Dust was a huge problem with most of the earlier CDROMs. And a bigger problem when CD-RW came along. On my first trip to Hasselt, Belgium with Philips I was introduced to the Calibrated Dust Machine. This is no BS. Philips worked with IBM to develop a chamber that was filled with fine dust under slight pressure. The optical drives would be tested to failure. Some of the early drives would only go minutes before failure. Often powering them down and starting up was enough to remove the dust for a short time. Engineering would also test all the competitors to see how they sealed their units and how long they lasted. LG had by far the best seals around the OPU. Philips redesigned all their front doors and bezel seals to improve dust immunity. And sold testing to other companies. One of those memories that lasts a lifetime: the test engineer complaining about how hard it was to buy calibrated dust. Billy