Low End Mac Reader Specials

TypeStyler For Mac OS X is Now Shipping! Download The Free Fully Functional 60 Day Tryout at www.typestyler.com

Poker Mac Don't install Parallels to play poker online! Poker Mac will show you how to download and install a native Mac poker application such as Full Tilt Poker Mac.

Laptop Hardware Provided by TechRestore - Overnight Mac & iPod Repairs.

Compare products like desktop computers, apple laptops, apple macs, and LCD Monitors side by side! All the information and reviews to make the best purchasing decision for new mobile phones, sat nav systems, or MP3 players. The Ciao online shopping community makes searching products easy for you.

Low End Mac's Online Tech Journal

Macintosh Makes the Connection

Dan Knight - December 1997

Surprising to many, the first Macs didn't have SCSI. The Apple design team created a compact, closed box with a disk drive, CPU, monitor, 128KB of RAM, keyboard and mouse ports, a floppy drive port, and two serial ports. The serial ports were the secret - they could support a 230.4Kbps network and be used for system expansion. Apple called the latter their high speed serial bus.

It never caught on.

SCSI

In 1986 Apple released the Mac Plus. Not only did it come with 1 MB of RAM (expandable to 4 MB!), there was a new hard drive connector called SCSI. This was far, far faster than the older serial hard drive. And SCSI allowed adding one, two, up to seven devices to the Mac in a single chain.

Over time Apple improved their SCSI implementation. The Plus topped out at 2,104kbps, but the 1987 Mac II and SE offered improved throughput of 11,200kbps and 5,248kbps, respectively. Over the years, both Apple and third-party vendors offered Fast SCSI, Wide SCSI, Fast-Wide SCSI, and Ultra-SCSI.

But SCSI is running out of steam in the era of digital video. For a more detailed overview of SCSI, read SCSI Throughput.

ADB

With the Mac II and SE, Apple eliminated the dedicated keyboard and mouse connectors of the past for a new peripheral bus. Like SCSI, you can daisy-chain devices on the ADB bus. The earliest ADB Macs came with two ports, although Apple reduced that to one over the years.

Time to make a personal plug for the MicroSpeed KB101M keyboard. Not only does it provide identical layout the Apple's extended keyboard with superior components to the current keyboard, but it has 4 ADB ports. One ties the keyboard to the computer; others can be used for a mouse, a trackball, or some other ADB device. Highly recommended.

For a time, ADB was so cool that someone even made an ADB modem. There was enough spare bandwidth to comfortably support 2400bps. But over time the 10Kbps throughput of ADB became a bottleneck. Enough for a mouse or keyboard, it's insufficient for touch tablets and modems.

FireWire

The next hot technology from Apple is IEEE 1394, commonly known as FireWire. Faster and more flexible than SCSI, FireWire offers several advantages.

  • 100Mbps minimum bandwidth, with 400 available today and 1Gbps by 2000
  • devices negotiate fastest mutually supported data transfer speed
  • capable of supporting 63 devices (v. SCSI's seven)
  • can be used between computers, not just peripherals (should put ethernet to shame)
  • devices can be hot plugged, eliminating need to power down CPU and peripherals
  • high speed serial protocol requires just 6 wires, allowing small connectors and thin, flexible cabling
  • can provide up to 60 watts of power to peripherals, often eliminating need for separate power
  • auto configuration eliminates need to set device IDs

Sony has already adopted FireWire on their digital video cameras. Musicians are discovering FireWire as an option for wiring together electronic instruments, making it a replacement for MIDI.

For hard drives, digital video, high speed networking, and scanning, FireWire will eventually supplant SCSI.

USB, the Universal Serial Bus

This standard came from the other side of the tracks, Microsoft and Intel. USB has become common in the Wintel world and is well on the way to becoming the de facto keyboard and mouse port. But with a bandwidth of 12Mbps and typical speeds of 6-8Mbps, it's also fast enough for digital audio and modems. It is especially in the latter realm that USB is promising.

Mac serial ports have limited throughput, especially if LocalTalk is active (see Macintosh Serial Throughput). With DSL and cable modems just around the corner promising 1Mbps and higher throughput, we need another way to connect them. One option is the 10Mbps ethernet port. Another is using a PCI-based modem on a card, just like the Wintel world has done for years with internal modems.

USB provides sufficient throughput for ADSL, CDSL, and cable modems. It should be much less expensive to implement than FireWire, especially if it replaces ADB for mouse and keyboard connection.

For more on USB, read USB, okay for the low end.

The Future

While SCSI and ADB were adequate a few years ago, they are showing their age. Over the coming years, expect FireWire and USB or some similar technology to replace both.

Further reading

Recent Online Tech Journal Columns

Links for the Day

Recent Content on Low End Mac

Recent Deals

About LEM | Support | Usage | Privacy | Contacts

Entire Low End Mac website copyright ©1997-2009 by Cobweb Publishing, Inc., unless otherwise noted. All rights reserved. Advice presented in good faith, but what works for one may not work for all. Please report errors to .
  LINKS: We allow and encourage links to any public page as long as the linked page does not appear within a frame that prevents bookmarking it.
  Access our RSS news feed at http://lowendmac.com/feed.xml.
  Email may be published at our discretion; email addresses will not be published without permission, and we will encrypt them in hopes of avoiding spammers. If you prefer your message not be published, mark it "not for publication." Letters may be edited for length, context, and to match house style.
  PRIVACY: We don't collect personal information unless you explicitly provide it. For more details, see our Terms of Use.
  Low End Mac is an independent publication and has not been authorized, sponsored, or otherwise approved by Apple Inc. Apple, the Apple logo, Macintosh, iBook, iMac, eMac, iPod, iPhone, PowerBook, MacBook, MagSafe, Mac Pro, Apple TV, and AirPort are registered trademarks of Apple Inc. Additional company and product names may be trademarks or registered trademarks and are hereby acknowledged.

Custom Search

Amazon.com

Navigation

Used Mac Dealers
Apple History
Video Cards
Email Lists

Favorite Sites

MacSurfer
MacMinute
MacInTouch
MyAppleMenu
InfoMac
Macs Only!
The Mac Observer
Accelerate Your Mac
RetroMacCast
PB Central
MacWindows
The Vintage Mac
   Museum
DealMac
DealsOnTheWeb
Mac2Sell
ramseeker
Mac Driver Museum
JAG's House
System 6 Heaven
System 7 Today
the pickle's Low-End
   Mac FAQ
Abandonware
   Petition
Mac vs. PC Info

Affiliates

The Apple Store
Mac Connection
B&H
MacMall
TechRestore
ExperCom
Crucial Memory
batteries.com

Advertise

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.

Open Link

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.