Larry, John, Steve, and Bruce
If you click on the About menu item under System 6, on the right you can see a list of names: Larry, John, Steve, and Bruce. These are the names of the developers of this version of the Finder, the interface of the Macintosh

At the time Apple still used to give credit to developers by allowing them to appear in the info boxes of the software they had created. Usually their names appeared in full, sometimes even with pictures, but here all we have are the first names. Let’s see who these four are.
The last two, are the easiest to guess: they are of course Steve Capps and Bruce Horn.
Horn is the creator of the original Finder, a task in which he had the crucial assistance of Capps, who later had a key role in the Newton.
Larry is Larry Kenyon, longtime Apple and Mac developer. Kenyon, among other things, worked on Multifinder, the version of the Finder that starting from System 5 allowed Macintosh users to keep open many applications and switch between them bringing their windows to the front.
John is John Meier, who also worked on the Newton project and would keep on being a developer of subsequent versions of the Finder, the only one of the four names to do so.
The other new features of Mac OS 9
The most touted feature of Mac OS 9 was the new Sherlock 2 but there were lots of other new features, mostly related to the development and coming of the NeXT generation operating system, Mac OS X.
Mac OS 9 had multiple users, Voiceprint password, Keychain, automatic updating, encryption, Internet File Sharing, Internet AppleScript, and Network Browser. Many of these were direct equivalents of Mac OS X features which were concurrently developed or even backported.
The reason was of course to make the Mac OS more powerful and more modern but also to ease the transition to OS X, which at the time was believed to start in less than an year
Image taken from Toastytech.com
Ten years ago: here comes Mac OS 9
On October 22, 1999 Apple launched Mac OS 9, its major new release of the Macintosh operating system.
The last boxed edition of the “classic” Mac OS line carried a retail price of 99 USD (with a 20USD rebate for customers who owned Mac OS 8.5 or 8.6) and featured new Internet tools such as Sherlock 2, which was lauded by CEO Steve Jobs in the press release.
The updated version of Apple’s search tool was explicitly modified with a plugin system so that the new Sherlock could access search engines, websites, services and even follow auctions, helping the users with information retrieval but also shopping and online commerce.
To launch the operating system Apple Authorized Resellers (among which were chains such as CompUsa, Sears and Fry’s) held throughout the following weekend special Mac OS 9 “Midnight Madness” events, Apple Demo Days and in-store promotions.
The October 2009 MacBook: bye bye, Firewire

MacBook (May 2006)
USB: 2 2.0
Firewire: 1
MacBook (Late 2006) (November 2006)
USB: 2 2.0
Firewire: 1
MacBook (Mid 2007) (May 2007)
USB: 2 2.0
Firewire: 1
MacBook (Late 2007) (November 2007)
USB: 2 2.0
Firewire: 1
MacBook (Early 2008) (February 2008)
USB: 2 2.0
Firewire: 1
MacBook (Early 2009) (January 2009)
USB: 2 2.0
Firewire: 1
MacBook (Mid 2009) (June 2009)
USB: 2 2.0
Firewire: 1
MacBook (Late 2009?) (November 2009)
USB: 2 2.0
Firewire: none
The “Fat” Mac
On September 1984 Apple released the follow-up to the Macintosh, addressing one of the major complaints of potential buyers.
Sold for USD 3,300 (or 3200, according to some sources), the Macintosh 512K was nicknamed “Fat Mac” for its increased (four-fold) RAM memory but was otherwise identical to the original Macintosh, as one can see from the dual-purpose motherboards.
In an 1984 interview in Byte with three of the original designers of the Macintosh, Jef Raskin actually revealed that the expansion was planned since the beginning and wasn’t an afterthought.
At the question
You started with 64K bytes and it was released with 128K bytes, and there is constant talk of a half-megabyte Mac. When did a half megabyte creep into the design philosophy?
Raskin answered:
Very early on Burrell [Smith, the motherboard designer, nda] pointed out that it’s very easy to make a design, once you had the 68000 in place, where you could just take out 64K-bit chips and put in 256K-bit chips. I’ve always believed that you just simply take the largest chip that is economically feasible to use in terms of the memory, and if they’re bit-wide chips and you use 8 or 16 of them, then that should be the size of your memory. [...] Burrell loves designing for it, software part portion had no trouble handling that, and it was was very clean. When the 256K-bit chips come you just plug in all those and everything runs just about the same.
And things ran just about the same, but better: the 512k greatly improved application usage and even some operations helping avoid issues such as the “Disk Swapper’s Elbow”.
It was discontinued in April 1986, replaced by the 512Ke which had bigger ROMs (128K instead of 64) and used more capacious 800KB floppy disks.
The motherboard in the picture was gently provided by Maurizio Buso
