• Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint

NewWorld Macs

As noted in Chapter 1, all Macs have something called a ROM chip located on their logic board. Traditionally, this ROM not only contained the instructions necessary to initially start up (boot) the Mac, but it contained the code for many of the common Mac OS interface components—such as menus and dialog boxes. This common set of tools has tremendous advantages. It allowed all Mac applications to share these common interface components, giving all applications a similar look and feel, without requiring that the programmer of each application re-invent the wheel to accomplish this.

However, having this information in ROM also had its disadvantages. Primary among them is that it is difficult to modify and update the ROM, as it requires either a hardware replacement (which Apple virtually never does) or a series of software "patches" (in the form of extensions and/or enablers) that can lead to a series of different files needed for each model of Mac. The obvious solution (especially as a Mac's typical RAM and hard drive sizes increased) was to move the ROM to the hard drive and then load the information into memory (RAM) at startup.


PREVIEW

                                                                          

Not a subscriber?

Start A Free Trial


  
  • Creative Edge
  • Create BookmarkCreate Bookmark
  • Create Note or TagCreate Note or Tag
  • PrintPrint