Cmos?

Discussion in 'Mac Basics and Help' started by ronni3, Apr 27, 2007.

  1. ronni3 macrumors regular

    Joined:
    Dec 26, 2006
    Location:
    Chicago, IL
    #1
    Does Mac have a CMOS like PC? Like a central location for hardware configurations? Just wondering! ;)
     
  2. Eraserhead macrumors G4

    Eraserhead

    Joined:
    Nov 3, 2005
    Location:
    UK
    #2
    I'm not familiar with CMOS, but Apple Menu==>About this Mac==>More Info gives you the system profiler which sounds like what you are looking for...
     
  3. wrldwzrd89 macrumors G5

    wrldwzrd89

    Joined:
    Jun 6, 2003
    Location:
    Solon, OH
    #3
    Actually, it depends on the Mac. Macs made prior to the original "Bondi Blue" iMac G3 were "Old World", and stored their hardware information in PRAM (parameter RAM). Macs made after the iMac G3 was introduced (including the iMac G3 itself), but before the Intel transition, are "New World", and use Open Firmware for this purpose. Intel-powered Macs use EFI (Extensible Firmware Interface).
     
  4. ronni3 thread starter macrumors regular

    Joined:
    Dec 26, 2006
    Location:
    Chicago, IL
    #4
    Is there a way to access the EFI as you would with the BIOS in a PC?
     
  5. Fearless Leader macrumors 68020

    Joined:
    Mar 21, 2006
    Location:
    Hoosiertown
    #5
    thought they stilled used pram.

    no, well kinda, but not what you want.
    since its just a location in memory you can edit those points, thats what the fan control software does.
     
  6. trainguy77 macrumors 68040

    Joined:
    Nov 13, 2003
    #6
    People have managed to get into it as i recall. But there isn't a ton you can do. What are you looking to change?
     
  7. ronni3 thread starter macrumors regular

    Joined:
    Dec 26, 2006
    Location:
    Chicago, IL
    #7
    I didn't have any intentions of changing anything, I just wanted to get more insight on how the Mac functions.
     
  8. mkrishnan Moderator emeritus

    mkrishnan

    Joined:
    Jan 9, 2004
    Location:
    Grand Rapids, MI, USA
    #8
    This is a confusion between terminologies....

    BIOS, Open Firmware, and EFI in essence all refer to what is controlling the boot process -- they're all terms that describe software.

    CMOS, NVRAM, etc, are terms that refer to how that software is stored -- they are terms that describe the hardware.

    Some of these terms get used interchangeably for the hardware and the hardware -- for instance, some people say PRAM and mean the type of flashable memory used for parameters. Others specifically refer to the function the PRAM that is in PPC Macs does.

    Anyway, though, the equivalent to starting up in BIOS on a Windows PC, on a PPC Mac, is booting into Open Firmware. On an Intel Mac, Apple, as far as I know, does not contain a utility that allows for making changes to EFI, but there are utilities available:

    http://refit.sourceforge.net/
     
  9. gauchogolfer macrumors 603

    gauchogolfer

    Joined:
    Jan 28, 2005
    Location:
    American Riviera
    #9
    CMOS (Complementary Metal-Oxide Semiconductor) just refers to a type of transistor technology in which a set of MOSFETs is used for logic circuitry. In a MOSFET, a gate metal sits on top of a semiconductor channel, separated by an oxide insulating layer. These form a large class of integrated circuit technology, used not only in computer processors and memory, but focal plane arrays for digital cameras, transceivers, etc.

    For more, here's what Wikipedia has to say.
     

Share This Page