Hmm, this got way longer than anticipated. :) Even busted the list's 10K size limit. Next part in next message. :) If Dan thinks it's good enough for my much neglected "Trailing Edge" on Low End PC (or even *gasp* good enough for a spot somewhere on LEM) be my guest, I think it's a bit long and probably too rambling....
--- mart <[EMAIL PROTECTED]> wrote: > Hi Gregg, > > Now you confuse me. > Emphasizing the word 'special' here, and directly > leaving it out, would you > agree that everywhere and anytime in PC-world, the > basic PC setup program > *does write a driver* to a HD? > Because that's how I always understood it. I'm open > to new insights, but > not because of misunderstanding a posting. I'll do a simple summary first. When dealing with a Mac prior to the Blue & White G3, they have a ROM chip with a whole bunch of common code that every program uses. The ROM also takes care of the little details of talking to all the hardware so most programmers and users never have to bother with it. The PC doesn't have the big ROM with lots of code in it so any operating system that runs on one has to take care of everything on its own. Beginning with Windows 95 much of the detailed knowledge formerly required to install it on a PC was no longer needed. Windows would take care of it for the user. But it's taken until Windows XP to get to the point where it all really goes on "hands free". Everything worked very well on my PC here when I installed XP. For the first time with Windows I didn't _have_ to tweak and twiddle to optimize it, but I did anyway. The neat thing is I can, and I didn't need to use the command prompt at all. Now more advanced info. The ROM (or Toolbox ROM) in a Mac contains much of the basic functionality of the Mac System. It's customized for each model of Mac so that the hardware interface looks pretty much identical to the System software on each Mac. That's why you can install a System on a drive in a IIci then be able to use it to boot up a Mac II. The part of the ROM that communicates with a hard drive expects to be able to use the same commands to work with any hard drive. The disk driver that gets installed into it's own special partition takes care of the "translation". The System and the ROM never are bothered with knowing anything about the physical layout of the drive other than the amount of space available. The HD SC or Drive Setup program from Apple gets that info then sets up the driver appropriately for that drive. Third party utilities do the same. Until Windows For Workgroups 3.11, the DOS/Windows combination always used the BIOS for access to the hard drive. WFWG introduced "32bit Disk and File Access" which the user had to manually turn on with a control panel that had seperate selections for Disk Access and File Access. When both worked it sped things up quite a bit, if only one worked OK there was no point to turning on just one. Windows 95 and newer by default use full 32bit access to the hard drives and most other hardware. Some 16bit drivers for certain hardware will work in Win9x and WinMe, but WinNT/2000/XP need 32bit drivers. If there is a hardware conflict or you have to boot in Safe Mode they'll "dumb down" to 16bit mode using the BIOS but it's incredibly slow. Other than for the various problems PCs have had over the years keeping up with changing hard drive technology, there's been no need for any driver software to be in a specific location on the hard drive. Any other drivers for peripherals or things that used to be peripherals but are now integrated into the motherboard are loaded by the operating system similar to extentions and control panels on a Mac. The Macintosh was developed with little RAM (128K) and little storage (400K floppy disk) so to be able to have the graphical user interface and also to be able to communicate with the various hardware of the computer, the logical place to put all that common and always needed code was in a (relatively) big ROM. That way it needn't be included on every bootable floppy where it would have taken up half the disk. By 1984 the IBM/AT was available with a 1.2 megabyte floppy disk, a 20 megabyte hard drive and 640K RAM. The Mac was designed to run one operating system and all apps were expected from the beginning to use all that ready made code in the ROM. A Mac programmer didn't have to bother with writing code to send the correct data to the video system or other peripherals, the ROM or an INIT took care of that. The PC with it's simple BIOS allowed wide open hardware options, but that also brought with it the responsibility of each device maker to write a DOS driver that would load into memory without conflicting with something else. Filling all the expansion slots and making it all work was often a challenge for the best PC tech. Windows 95 changed that. It didn't need anything from DOS except to "hand off" control once the IO.SYS file was loaded from the drive. Even before Win95, Windows NT only needed the IO.SYS file to get booted, everything from there on was taken care of by Windows. Win 2000 and Win XP are the same way. The limited BIOS allowed the PC platform to be very flexible in running software but it also put the full burden of making sure the bells didn't whistle and the whistles didn't bong on the programmers. :) Of course that also means that all the code that provides the Windows GUI is part of Windows and takes up space on the hard drive, then space in RAM when the PC is running. Today's Macintosh is little different from Today's PC. Since the Blue & White G3 the Mac has been using a tiny ROM who's only job is to get the initial hardware startup squared away then go looking for the "ROM", which is now a file on the hard drive, to load into RAM which then takes over and loads up the Mac OS. It's very much like how the PC BIOS initializes and does basic tests on the hardware then goes looking for IO.SYS which then hands over control to Windows. The main difference is that the IO.SYS file is very small and the Mac ROM file is a few megabytes now. Except for the CPU and the chipset, modern Mac hardware is from the same parts bins as a modern PC. IDE hard drives, PCI bus, USB ports, video controllers, etc. Apple has contributed the 1394 "Firewire" port but it's been much easier on Apple's bottom line to adopt the other pieces from the PC world where the massive production makes them cheap. The benefit of adopting all this plus going away from having the ROM in an unchangeable chip is what gave the Mac the flexibility to adopt/adapt the BSD operating system and the Aqua interface while doing away with any restrictions of having an unchangeable ROM that constantly had to be "spackled over" with patches from extentions when new features or a new look to the interface was desired. ===== http://www.junkscience.com "All the Junk that's fit to Debunk!" __________________________________________________ Do You Yahoo!? Yahoo! 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