Apple has used the SCSI bus since introducing the Mac Plus in 1986. The SCSI bus must have
termination power for clean data transmission.
Most Macs provide termination power for the SCSI bus, so most SCSI
devices for the Mac don't need to provide it. However, the Mac Plus, Portable, 100-series PowerBooks, 500-series
PowerBooks, and the PowerBook 1400 don't supply SCSI termination power
(see Which Model
Provide SCSI Termination Power?). Neither do Macs using IDE drives,
such as the Quadra 630 (aka LC 630,
Performa 63x) and many Power Macs (except for the 6100 and 7100-9600,
all Power Macs use IDE drives).
This may apply to some Maclones as well. However, Umax assures me
this is not the case with their Umax SuperMac C500 and C600. I've heard the same for the
Motorola StarMax models with EDI
drives.
All Apple and some third-party SCSI hard drives provide SCSI
termination power. This is essential for these drives to work with the
Plus, Portable, and most PowerBooks.
This is an important issue, because if you are using an external
drive that provides SCSI termination power on a Mac that doesn't
provide it, your Mac will hang if you turn off the hard drive before
turning off the computer. Also, the system may not boot from the
external drive if it is not powered before turning on the
Macintosh.
The source of the problem is a corrupted SCSI bus. Without
termination power, noise on the bus can prevent startup and cause a
lockup.
This is one reason Apple has always recommended you power up all
SCSI devices before or at the same time as starting the computer, but
never after the computer is running.
This is a good argument for buying only SCSI hard drives with active
termination, allowing them to determine what level of termination (if
any) is required in a given situation. (Of course, only the last device
in a SCSI chain is normally terminated. If you have devices with active
termination, one of them should be at the end of the chain with
termination enabled. Other drives should have termination turned
off.)
Apple's AAUI ethernet connector, 09.04.
From 1991 through 1995, Apple used a proprietary ethernet connection. Why they created AAUI and where to find adapters.
From Mac tinkerer to full time Mac user, Mike Tessitore, My Turn, 05.12.
It started with buying old Macs on eBay and tinkering with them. But when the Windows PC died, the author learned that Macs could do everything he needed.
Free Time Machine Editor does one thing and does it well, Alan Zisman, Zis Mac, 05.12.
If Time Machine's habit of backing up every hour is impacting your work flow, this free utility gives you control options that Apple didn't build into Time Machine.
Low End Mac's Compleat Guide to Mac OS 9, 2008 edition, Charles W. Moore, Miscellaneous Ramblings, 05.12.
Declared dead by Steve Jobs 6 years ago, Mac OS 9 remains fast and stable, but Classic software hasn't kept up with Web changes. What Macs support OS 9, where to buy it, and how to update it.
Mac of the Day: Classic II/Performa 200, Oct. 1991 - The last b&w compact Mac put a 16 MHz 32-bit CPU on a 16-bit bus.
List of the Day: Apple2list supports Apple II users.
May 13 in LEM history: 99: Cost effective upgrades for 68030s - 02: Free POP3 email - Penguin lockup mystery - 03: Safari and the Internet experience - Niners to Xers: Apple's Switch campaign for Mac users - 05: Xbox 360 specs put Power Mac G5 to shame - Which older Macs are good candidates for Tiger? - Tiger on an iBook - Does Mac mini kill the used Mac market?
Apple's eMate still a great tool in the classroom, Tommy Thomas, Welcome to Macintosh, 05.09.
How one teacher equipped his classroom with eMates with his own money - and plans to keep using them as long as possible.
140 million copies of Vista sold (yawn), Frank Fox, Stop the Noiz, 05.09.
It sounds like a lot, but over 85% of Windows users are staying away from Vista. 20% of Mac users have embraced Leopard in one-third the time.
Best Power Mac G4 deals, Low End Mac Deals, 05.09.
Used Cube, $479; 400 MHz PCI, $70; 450 AGP, $105; 733 DA, $150; 867 QS, $200; 1 GHz, $250; 450 dual, $295; 1 GHz dual, $400; 1.42, $600; more.
Best 15" MacBook Pro deals, Low End Mac Deals, 05.09.
Used 1.83 GHz Core Duo, $1,100; 2.16, $1,295; refurb, 2.2 Core2, $1,449; 2.4 Penryn, $1,699; 2.5, $2,149; new 2.2, $1,525 after rebate; 2.4, $1,685 a/r; more.
Best iPod touch deals, Low End Mac Deals, 05.09.
Refurb 8 GB '08, $249; 16 GB '07, $329; '08, $349; new 8 GB '07. $269; '08, $280; 16 GB '07, $330; '08, $369; 32 GB, $475.
All of our advertising is handled by BackBeat Media. For
price quotes and advertising information, please contact
at BackBeat Media
(646-546-5194). This number is for advertising only.
Problems viewing this page with Internet Explorer
5.5 or 6? It works fine in other browsers, including IE 7. We
recommend Firefox
for those using Windows, as it is standards based and more
secure than IE 6 (and earlier). More LEM visitors use Firefox
than any other browser.
