Vintage Macs: Centris and Quadra

Centris 650

Macintosh Centris 650 "Going along with the auto-marketing trend toward meaningless names that sound important, Apple's new Centris line will serve as the company's mainstream, midlevel computers." MacUser, April 1993 (Apple names included Quadra, Performa, and Centris. The Centris name was dropped after just 9 months.)

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Overview

Creating a midpoint between the Mac II line and the Quadra series, the short-lived Centris models were introduced in February 1993. The Centris 650 uses the same chassis as the IIvx and IIvi. Some models came with a 68LC040 (no math section), only 4 MB RAM, and no ethernet. Most use the full 68040 and have ethernet, as well as 8 MB of motherboard RAM.

The 650 introduced a higher speed SCSI bus to the Macintosh line as well as accelerated internal video. It also used interleaved memory to squeeze out about 10% more performance. All this made the Quadra 700 obsolete; the Q700 was dropped from Apple's lineup with the Centris rollout.

The Centris 650 and Quadra 800 were the first Macs to ship with a bootable CD-ROM.

The floppy drive mounting sled used in the IIvi, IIvx, Centris 650, Quadra 650, and Power Mac 7100 can also be used for a hard drive if you no longer need the floppy drive.

Apple earns a Road Apple for the Centris name, which was discontinued after 9 months. Despite that, the Centris 650 is an excellent value on the used market, especially versions with ethernet and the full 68040 processor.

See our NuBus Video Card Guide for information on adding a video card.

The Upgrade Box

Details

introduced 1993.02.10 at $2,700; replaced by Quadra 650 1993.10.21
requires System 7.1 or later; highest version supported without a PPC upgrade is Mac OS 8.1.
CPU: 25 MHz 68040 or 68LC040
performance: 12.0, relative to SE; 0.99, Speedometer 4; 22 MIPS
ROM: 1 MB
RAM: 4 MB or 8 MB on motherboard, expandable by 128 MB using four 80ns 72-pin SIMMs; motherboard had 4 SIMM slots which can be filled individually but should ideally be filled in neioghboring pairs to take advantage of interleaved memory; can use 4 MB, 8 MB, 16 MB, and 32 MB SIMMs
video: 512 KB VRAM, expandable to 1 MB
- 512 x 384 @ 16-bit
- 640 x 480, 800 x 600, 832 x 624: 8-bit @ 512 KB, 16-bit @ 1 MB
- 832 x 624, 1024 x 768, 1152 x 870: 4-bit @ 512 KB, 8-bit @ 1 MB
L2 cache: optional, PDS
ADB ports: 2
DIN-8 serial ports: 2
SCSI: DB-25 connector on back of computer
hard drive: 80, 230, or 500 MB
NuBus 90 slots: 3
one PDS slot
size (HxWxD): 6.0" x 13.0" x 16.5"
weight: 25 lbs.
PRAM battery: 3.6V half-AA
Gestalt ID: 30
addressing: 24-bit or 32-bit
upgrade path: Quadra 650, Power Mac PDS card, Power Mac 7100

Accelerators & Upgrades

Chipping the Centris
Chipping the QuadDoubler, a guide to clock chipping Sonnet QuadDoubler.
Output Enablers 28.6-29.5 MHz clock accelerator
MicroMac Speedy variable speed oscillator (to 29 MHz)
Sonnet QuadDoubler (50 MHz 68040)
Daystar Digital PowerPro 601, Apple Knowledge Base Archive. Runs at twice the speed of the original processor (50 MHz) and has a 1 MB level 2 cache (resource: Unofficial PowerPro 601 Page.
Power Mac 7100
Sonnet 100 MHz PowerPC 601 Presto PPC, discontinued

Accelerator Reviews

Sonnet Quad Doubler

Online Resources

Low End Mac's best classic Mac OS deals. Best online prices for System 6, 7.1, 7.5.x, Mac OS 7.6, 8.0, 8.1, 8.5, 9.0, 9.2.2, and other versions.
Know your Mac's upgrade options, Phil Herlihy, The Usefulness Equation, 2008.08.26. Any Mac can be upgraded, but it's a question of what can be upgraded - RAM, hard drive, video, CPU - and how far it can be upgraded.
The compressed air keyboard repair, Charles Moore, Miscellaneous Ramblings, 2008.07.24. If your keyboard isn't working as well as it once did, blasting under the keys with compressed air may be the cure.
Tales of old Mac data retrieval, Adam Rosen, Adam's Apple, 2008.06.13. Getting apps and documents off 400K floppies, old disk images, and a Mac running System 5.
A vintage Mac network can be as useful as a modern one, Carl Nygren, My Turn, 2008.04.08. Old Macs can exchange data and share an Internet connection very nicely using Apple's old LocalTalk networking.
Vintage Mac networking and file exchange, Adam Rosen, Adam's Apple, 2007.12.19. How to network vintage Macs with modern Macs and tips on exchanging files using floppies, Zip disks, and other media.
Vintage Mac video and monitor mania, Adam Rosen, Adam's Apple, 2007.12.17. Vintage Macs and monitors didn't use VGA connectors. Tips on making modern monitors work with old Macs.
Getting inside vintage Macs and swapping out bad parts, Adam Rosen, Adam's Apple, 2007.12.14. When an old Mac dies, the best source of parts is usually another dead Mac with different failed parts.
Solving Mac startup problems, Adam Rosen, Adam's Apple, 2007.12.12. When your old Mac won't boot, the most likely culprits are a dead PRAM battery or a failed (or failing) hard drive.
Why you should partition your Mac's hard drive, Dan Knight, Mac Musings, 2008.12.11. "At the very least, it makes sense to have a second partition with a bootable version of the Mac OS, so if you have problems with your work partition, you can boot from the 'emergency' partition to run Disk Utility and other diagnostics."
Better and safer surfing with Internet Explorer and the Classic Mac OS, Max Wallgren, Mac Daniel, 2007.11.06. Tips on which browsers work best with different Mac OS versions plus extra software to clean cookies and caches, detect viruses, handle downloads, etc.
Hacking Mac OS 7.6.1 so many Mac OS 8 apps will run, Max Wallgren, Mac Daniel, 2007.10.30. With a little ResEdit work and a second copy of your System Folder, you can run a lot of OS 8 apps with Mac OS 7.6.1.
It all started with a Mac Plus in the classroom, Robert Alpizar, My First Mac, 2007.10.29. "Over time, as I began to see how much simpler the Macs were to use vs. the DOS computers, I began to explore them more."
Simple Macs for simple tasks, Tommy Thomas, Welcome to Macintosh, 2007.10.19. Long live 680x0 Macs and the classic Mac OS. For simple tasks such as writing, they can provide a great, low distraction environment.
Interchangeabilty and compatibility of Apple 1.4 MB SuperDrive floppy drives, Sonic Purity, Mac Daniel, 2007.09.26. Apple used two kinds of high-density floppy drives on Macs, auto-inject and manual inject. Can they be swapped?
Apple's AAUI ethernet connector, Dan Knight, Online Tech Journal, 2007.09.04. From 1991 through 1995, Apple used a proprietary ethernet connection. Why they created AAUI and where to find adapters.
Connecting a LaserWriter to ethernet and the TiBook that wouldn't boot, Dan Knight, Low End Mac Mailbag, 2007.08.23. The importance of an AAUI ethernet adapter, the cost of PowerBook PRAM batteries, and booting old Macs from SCSI drives.
Apple's first phone a fake, build your own Macintel, Internet options for G3 Macs, and more, Dan Knight, Low End Mac Mailbag, 2007.07.23. Also a Cube that won't boot, moving data from an old Mac, useful resource for PowerBook 1400 owners, reformatting a Quadra's hard drive, finding an AirPort power supply, and more.
Mac System 7.5.5 can do anything Mac OS 7.6.1 can, Tyler Sable, Classic Restorations, 2007.06.04. Yes, it is possible to run Internet Explorer 5.1.7 and SoundJam with System 7.5.5. You just need to have all the updates - and make one modification for SoundJam.
Appearance Manager allows Internet Explorer 5.1.7 to work with Mac OS 7.6.1, Max Wallgren, Mac Daniel, 2007.05.23. Want a fairly modern browser with an old, fast operating system? Mac OS 7.6.1 plus the Appearance Manager and Internet Explorer may be just what you want.
Importance of G3 support in 10.5, clever USB/FireWire solution, upgrade options, and more, Dan Knight, Low End Mac Mailbag, 2007.05.01. Also the loss of the PowerBook brand, upgrading to an Intel iMac, Korg and the Mac, Quadra boot problems, and the value of a Mac Classic.
Format any drive for older Macs with patched Apple tools, Tyler Sable, Classic Restorations, 2007.04.25. Apple HD SC Setup and Drive Setup only work with Apple branded hard drives - until you apply the patches linked to this article.
Project Quadra: Building a FrankenMac from a Quadra 700, IIci, and IIvx, Joseph Burke, My Turn, 2007.04.19. How a found Mac IIci plus an eBayed Q700 mainboard ended up in a Mac IIvx found at a neighbor's yard sale.
Making floppies and CDs for older Macs using modern Macs, Windows, and Linux PCs, Tyler Sable, Classic Restorations, 2007.03.15. Older Macs use HFS floppies and CDs. Here are the free resources you'll need to write floppies or CDs for vintage Macs using your modern computer.
System 7 Today, advocates of Apple's 'orphan' Mac OS 7.6.1, Tommy Thomas, Welcome to Macintosh, 2006.10.26. Why Mac OS 7.6.1 is far better for 68040 and PowerPC Macs than System 7.5.x.
Mac OS 8 and 8.1: Maximum size, maximum convenience, Tyler Sable, Classic Restorations, 2006.09.11. Mac OS 8 and 8.1 add some useful new features and tools, and it can even be practical on 68030-based Macs.
Moving files from your new Mac to your vintage Mac, Paul Brierley, The 'Book Beat, 2006.06.13. Old Macs use floppies; new ones don't. Old Macs use AppleTalk; Tiger doesn't support it. New Macs can burn CDs, but old CD drives can't always read CD-R. So how do you move the files?
Setting up a 68040-based Mac media center, Nathan Thompson, Embracing Obsolescence, 2006.05.12. Yes, that old '040-based Quadra or Performa just might make a decent media center for listening to MP3s and watching videos.
System 7.6.1 is perfect for many older Macs, John Martorana, That Old Mac Magic, 2006.03.24. Want the best speed from your old Mac? System 7.6.1 can give you that with a fairly small memory footprint - also helpful on older Macs.
System 7.5 and Mac OS 7.6: The beginning and end of an era, Tyler Sable, Classic Restorations, 2006.02.15. System 7.5 and Mac OS 7.6 introduced many new features and greater modernity while staying within reach of most early Macintosh models.
Web browser tips for the classic Mac OS, Nathan Thompson, Embracing Obsolescence, 2006.01.03. Tips on getting the most out of WaMCom, Mozilla, Internet Explorer, iCab, Opera, and WannaBe using the classic Mac OS.
Resurrected Centris, Chris Lawson, 2000.06.27 and 2000.07.07
Options For '040s, Adam Robert Guha, Apple Archive, 2000.06.05. Advice about operating systems, upgrades, what Quadra to choose, and more.
Games for '040s, Low End Mac Gaming, Brian Rumsey, 2000.02.25. This week Brian looks at games to play on 68040-based Macs.
Gaming on '040s, Brian Rumsey, Low End Mac Gaming, 2000.02.16. Those old 68040-class Macs still have game.
6100 DOS Cards, Quadras, and You. How to use a Power Mac 6100 DOS card with 66 MHz 486DX2 CPU in a Quadra
72-pin SIMM memory pricing, ramseeker
What Can I Do with a Quadra or Centris 650?, Mac Daniel
Is upgrading my Centris 650 worth it?, Mac Daniel
Centris 610, 650, 660av Differences
Vintage Macs, the email list for 68040-based Macs
Memory Upgrade Guide
Interleaved Memory on Centris 650 & Quadra 800, Dale Adams
Centris & Quadra 610, 650, and 800 Video Capabilities, Dale Adams, designer of video hardware on most Centris and Quadra models
Printed reviews: Macworld, April 1993; Mac User, April 1993
Macintosh Centris 650 Technical Specifications, Apple Knowledge Base Archive

Cautions

Apple discontined support and parts orders for this model on 2001.10.15 (2001.10.22 in Canada). You may be able to find dealers with parts inventory either locally or on our parts and service list.
You must have a "fat" system installed to use a PowerPC upgrade.
Serial port normally restricted to 57.6 kbps; throughput with a 56k modem may be limited. See 56k modem page. For more information on Mac serial ports, read Macintosh Serial Throughput.

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