Which version of Mac OS will my Macintosh run?

If you aren't sure which versions of the Mac OS are compatible with your Macintosh, here are some excellent resources to find out:

AppleCare's Knowledge Base includes several relevant articles on the topic:

• System Software: Version Matrix, System 6.0.x to 7.0.1
• System 7.1 through Mac OS 7.6: Compatibility With Macintosh Computers
• Mac OS 8 and 9 Compatibility with Macintosh Computers
• Mac OS: Versions, builds included with PowerPC Macs (since 1998)
• Mac OS X Versions (builds) included with Intel-based Macs

My favorite tool for finding a quick answer to this question is Ian Page's awesome MacTracker, a comprehensive collection of vital information about every model of Macintosh that is available as a free Mac OS X or Windows application, or via a web site that's optimized for viewing on an iPhone or iPod Touch.

Now, as for which version of the Mac OS is optimal for your model of Macintosh, well, that's beyond the scope of this article. The folks over at lowendmac.com have a number of helpful articles on this topic, though.

System Picker

Dan Knight wrote an article for lowendmac.com back in 2001 entitled System 6 or System 7? In the article he describes several ways to switch between using System versions on the same Macintosh, and recommends a utility called System Picker:

System picker is a freeware utility that lets you pick which one of two or more System Folders on your hard drive will be active at the next startup. Kevin Aitken's little utility does this by "blessing" the system you select. (Blessing is Apple's name for selecting one System Folder as the active one.)

Unfortunately, the link to download System Picker from Apple's Developer site no longer works. I was able to locate a copy after a good bit of hunting, and that experience led me to decide that I would begin to collect and archive legacy Mac tools to save myself and others the time and frustration in the future. Until that archive is established you can find System Picker here.

I do not yet have personal experience with System Picker but plan to test it soon. Be sure to read Dan's excellent article for tips on how to install two different operating system versions on the same drive. Not sure which versions of the OS your Mac supports? See this article to find out!

Unscheduled downtime

Looks like when I installed the Ooma last night my DHCP supplied IP address was changed and dyndns.org didn't catch the update, so colorclassic.dyndns.org is not able to connect to the Color Classic web server until I get home to fix that.

And I was hoping that this would be a 100% uptime month! Maybe January ...

Changes for early December 2008

I haven't found a way to get the hard drive to spin down on the Color Classic even when all of the applications are running off a RAM disk, so I've given up on that option. When this hard drive calls it quits I may decide to seek silence by installing a solid state drive like the clever fellow over at junkstation did for his Performa 450! I have an 8G compact flash sitting in a drawer from an old Canon digital camera that would increase drive space on the Color Classic by a factor of 100 and reduce heat and noise inside the case dramatically.

The web pages have been updated to include a new banner (see previous blog posting) as well as a little sound easter egg you can hunt for yourself.

The Belkin wireless gateway arrived but I've not had a chance to test it yet. Right now I need to get my new Ooma Hub online to quit paying for phone service!

Banner for legacy Mac servers

Apple entered the internet server market on April 10, 1995 when they introduced their Apple Internet Server Solution at Internet World in San Jose, CA. The press announcement described it as "an affordable and easy way to establish a presence on the Information Superhighway."

Included in the software bundled with the servers was a graphic logo for placement on web pages to tell the world they were hosted on a web server powered by an Apple Macintosh:

I've spotted this logo on a couple of web sites served up by legacy Macs and thought it rather clever, but decided to change it up a bit to send a more accurate message. You are welcome to add it to your web site if you like:

Color Classic internet connection over wireless?

Ever since I helped configure a wireless ethernet adapter at a friend's house I've pondered whether the Color Classic could be connected to the internet without a direct ethernet cable.

The folks at buy.com are offering a Belkin F5D7330 802.11g wireless ethernet adapter for $19.99 this week, so I decided to spring for the purchase and give it a try. The product description includes the following statements which give me a glimmer of hope:

• Works with all Ethernet-equipped computers or network devices
• Requires no drivers, setup, or configuration
• Comes with a Belkin Lifetime Warranty and free, 24-hour technical support
• Automatically connects to the wireless network by the touch of a button

One gotcha may be that it is USB powered (does not have an external adapter) but I plan to get around that with a spare iPod charging adapter with a USB socket that plugs into an AC outlet.

I'll report back on my progress after it arrives. If I get stumped I can always try their free technical support!

Running MacHTTP off a RAM disk?

I am considering trying to run MacHTTP from a RAM disk to reduce wear and tear on the hard disk of the Color Classic. The drive spins constantly while the machine is on (which is 24/7/365) and while the first drive lasted 15 years it only makes sense to conserve the life of the replacement and reduce the electricity the Color Classic uses if possible.

My Color Classic has 10MB of RAM (the maximum it can recognize). System software is using a whopping 4MB of that, and if MacHTTP runs for awhile it wants 4 MB, too. The only other application that I have running concurrently is ftpd for updating the server via ftp over my local network (my router blocks incoming ftp connections for security purposes).


The memory control panel will only let me set a RAM disk for a little over 3MB. Maybe setting the disk cache to higher number will help? I guess I need to review the memory usage concepts from System 7.6.x.