Many of the PowerMacs have a single SCSI bus. This bus was routed to the back panel connector as well as being used for internal devices. I know this to be the case on the 7200 line, as I was running one 'till recently.
The Powermacs not covered above have multiple SCSI buses. In this case, the fast bus(es) were kept inside the box exclusively, I believe. Example: My current machine, a WGS 7350, has at least two SCSI buses. I have devices on the external bus and one of the internal buses. The internal bus supports fast transfer, while the external bus does not. Interestingly, the internal devices are hooked up to the bus labelled "slow SCSI," but support fast transfer anyway! I believe it is true that Macs with multiple SCSI buses always send the slow one to the external connector. My advice to the original post-er: Go ahead and look into getting an external HD. I bought a 2-bay ex-SyDOS enclosure off Ebay a couple years ago and currently have it outfitted with a Plextor 12x drive and a Quantum Viking 2.3GB. The portability gained has been well worth it, for me. I'm a tinkerer, and this allows me to keep all my files in a central storage place. I can just hook up my box to whatever Mac I'm working with, whether a humble IIci or speedy G3. It's great portability, and your drive won't be any louder in a solid external box than it would be inside your Mac. The Viking 2.3GB is a hot, noisy, 7200-RPM unit, and I simply wasn't going to let it toast itself inside my LCIII. I wouldn't trust it to the empty bay in the 7500-series cases, either. Cooling seems to come at the cost of noise, though, and this is one noisy SCSI box! The whine of the Viking (this invites some sort of politically incorrect battle cry analogy) mingled with the rush of air from the dual cooling fans isn't what I want to lull me to sleep at night. Maybe that's why I'm still up. =) Current project: Triple-boot on my WGS, with Mac OS 8.1, Linux, & BeOS! Cheers, Jesse -- 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! | PowerON Computer Services <http://www.poweron.com> REPLACEMENT PARTS in STOCK Drives, CD-ROMs, RAM, Mac OS SW, Power Supply <mailto:[EMAIL PROTECTED]> Support Low End Mac <http://lowendmac.com/lists/support.html> PCI-PowerMacs list info: <http://lowendmac.com/lists/pci-powermacs.shtml> 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
