Old World ROM Macintosh computers are the Macintosh models that use a Macintosh Toolbox ROM chip, usually in a socket (but soldered to the motherboard in some models). All Macs prior to the iMac use Old World ROM, while the iMac and all subsequent models are New World ROM machines. In common use, the "Old World" designation usually applies to the early generations of PCI-based "beige" Power Macs (and sometimes the very first NuBus-equipped models), but not the older Motorola 68000-based Macs; however, the Toolbox runs the same way on all three types of machines. The first Macintosh computer, introduced in 1984, upgraded to 512KB. The Macintosh, or Mac, line of personal computers is designed, developed, manufactured, and marketed by Apple Computer. ... The Macintosh Toolbox was a set of resources, drivers, routines and APIs stored in the ROM of Old World ROM Apple Macintosh computers. ... Read-only memory (ROM) is a class of storage media used in computers and other electronic devices. ... The correct title of this article is iMac. ... This article needs to be cleaned up to conform to a higher standard of quality. ... 32-bit PCI expansion slots on a motherboard 64-bit PCI expansion slots inside a Power Macintosh G4 The Peripheral Component Interconnect standard (in practice almost always shortened to PCI) specifies a computer bus for attaching peripheral devices to a computer motherboard. ... NuBus is a 32-bit parallel computer bus, originally developed at MIT as a part of the NuMachine workstation project, and eventually used by Apple Computer and NeXT Computer. ... The Motorola 68000 is a 32 bit CISC microprocessor, the first member of a successful family of microprocessors from Motorola, which were all mostly software compatible. ...

PCI Power Macs with an Old World ROM contain an Open Firmware implementation, and a copy of the Macintosh Toolbox as an Open Firmware device. These machines are set to boot from this device by default, thus starting the normal Macintosh startup procedure. This can be changed, just as on New World ROM Macs, but with limitations placed on what devices and formats can be used; on these machines, particularly the early machines like the Power Macintosh 7200 and Power Macintosh 7500, the Open Firmware implementation was just enough to enumerate PCI devices and load the Toolbox ROM, and these Open Firmware revisions have several bugs which must be worked around by boot loaders or nvramrc patches. Open Firmware (also, OpenBoot) is a hardware-independent firmware (computer software which loads the operating system), developed by Sun Microsystems, and used in post-NuBus PowerPC-based Apple Macintosh computers, Sun Microsystems SPARC based workstations and servers, IBM POWER systems, and PegasosPPC systems, among others. ... The Power Macintosh 7500 was one of the first PCI capable Macs manufactured by Apple Computer. ...

All Power Macs include an emulated 68LC040 core that runs inside a nanokernel; this nanokernel/emulator combination is then used to boot the (predominantly 68k-based) Toolbox, and is also used to support applications written for the 68k once Mac OS is running. 68k machines can boot into the Toolbox directly. An emulator reproducing a console games playable atmosphere on a Windows computer. ... In computer science, the term nanokernel can refer to different concepts: an kernel that is even smaller in memory than (some) microkernels, the lowest-level part of the system software for PowerPC processor-based Macintosh computers. ...

On all Old World ROM machines, once the Toolbox is loaded, the boot procedure is the same. The Toolbox does a memory test, enumerates Mac OS devices it knows about (this varies from model to model), and either starts the onboard video (if present) or the option ROM on a NuBus or PCI video card. The Toolbox then checks for a disk in the floppy drive, and scans all SCSI buses for a disk with a valid System Folder, giving preference to whatever disk is set as the startup disk in the parameter RAM.

If a bootable disk is found, the Happy Mac logo is displayed, and control is handed over to Mac OS. If no disk to boot from is present, an icon depicting a floppy disk with a question mark in the middle blinks on the screen. If a hardware problem occurs during the early part of the boot process, the machine will play the Chimes of Death and freeze; on some Macs, this will be accompanied by a Sad Mac icon and an error code describing the problem. Happy Mac as shown in Mac OS 9. ... The Savior (1410s, by Andrei Rublev) For other senses of this word, see icon (disambiguation). ... The Chimes of Death, a. ... The sad Mac icon, this one indicating that an illegal instruction occurred. ...

Since the Old World ROM usually boots to the Toolbox, most OSes have to be installed using a boot loader from inside Mac OS (BootX is commonly used for Linux installations). 68K-based Macs and NuBus Power Macs must have Mac OS installed to load another OS (even A/UX, which was an Apple product), usually with virtual memory turned off. PCI Power Macs can be configured to boot into Open Firmware, allowing the firmware to load a boot loader directly, or they can use a specially-prepared floppy disk to trick the Toolbox into loading a kernel (this is used for Linux installation floppy images). In computing, booting is a bootstrapping process that starts operating systems when the user turns on a computer system. ... BootX is the name of the boot loader used on Apples Macintosh computers to load Mac OS X. It is BootX that locates the operating system kernel and the drivers necessary to start the operating system, loads them into system memory, and launches the kernel. ... A/UX (from Apple Unix) is Apple Computers implementation of the Unix operating system for some of their Macintosh computers. ... The memory pages of the virtual address space seen by the process, may reside non-contiguously in primary, or even secondary storage. ... Tux is the official Linux mascot. ...

See also

• BootX, the standard LinuxPPC boot loader for Old World machines