At 04:04 PM -0800 02/08/2003, Lavode wrote: >Dan C wrote: > >Um... You shutdown your Mac *before* you powered off the scanner, right? :) > >OK, so why is it that I have shut down my scanner tons of times with the >computer still powered on, and never had any problems? Blind luck?
You should always shutdown your Mac *before* powering off any SCSI device because: 1) Electrically, SCSI-1 and -2 are NOT designed to be hot swappable. The power flux can damage the other interfaces on the bus; the one on the mobo being most succeptable. 2) SCSI status is polled periodically by the Mac OS. And the OS doesn't understand (handle) sudden holes very well, so it reacts by crashing. That you haven't electrically damaged anything by turning off the scanner is luck. I've replaced three Mac mobos in the past year because their owners were fast with the power switches on their ZIP drives and scanners. Scanners usually just use a plug-in type "pseudo-driver" instead of a real driver, so the OS is more forgiving during polls. Note that some forms of SCSI-3 bus support hot swapping - that's a horse of a different color (and cost). - Dan. -- PCI-PowerMacs is sponsored by <http://lowendmac.com/> and... Small Dog Electronics http://www.smalldog.com | Refurbished Drives | -- Sonnet & PowerLogix Upgrades - start at $169 | & CDRWs on Sale! | Support Low End Mac <http://lowendmac.com/lists/support.html> PCI-PowerMacs list info: <http://lowendmac.com/lists/pci-powermacs.shtml> --> AOL users, remove "mailto:"; Send list messages to: <mailto:[EMAIL PROTECTED]> To unsubscribe, email: <mailto:[EMAIL PROTECTED]> For digest mode, email: <mailto:[EMAIL PROTECTED]> Subscription questions: <mailto:[EMAIL PROTECTED]> Archive:<http://www.mail-archive.com/pci-powermacs%40mail.maclaunch.com/> Using a Mac? Free email & more at Applelinks! http://www.applelinks.com
