New World ROM computers are

Macintosh The Mac (known as Macintosh until 1999) is a family of personal computers designed and marketed by Apple Inc. Macs are known for their ease of use and minimalist designs, and are popular among students, creative professionals, and software en ...

models that do not use a

Macintosh Toolbox The Macintosh Toolbox implements many of the high-level features of the Classic Mac OS, including a set of application programming interfaces for software development on the platform. The Toolbox consists of a number of "managers," software compone ...

ROM Rom, or ROM may refer to: Biomechanics and medicine * Risk of mortality, a medical classification to estimate the likelihood of death for a patient * Rupture of membranes, a term used during pregnancy to describe a rupture of the amniotic sac * ...

on the logic board. Due to

Mac OS X macOS (; previously OS X and originally Mac OS X) is a Unix operating system developed and marketed by Apple Inc. since 2001. It is the primary operating system for Apple's Mac computers. Within the market of desktop and la ...

not requiring the availability of the Toolbox, this allowed ROM sizes to shrink dramatically (typically from to ), and facilitated the use of flash memory for system firmware instead of the now more expensive and less flexible

Mask ROM Read-only memory (ROM) is a type of non-volatile memory used in computers and other electronic devices. Data stored in ROM cannot be electronically modified after the manufacture of the memory device. Read-only memory is useful for storing so ...

that most previous Macs used. A facility for loading the Toolbox from the startup device was, however, made available, allowing the use of

Mac OS 8 Mac OS 8 is an operating system that was released by Apple Computer on July 26, 1997. It includes the largest overhaul of the classic Mac OS experience since the release of System 7, approximately six years before. It places a greater emphasis o ...

and Mac OS 9 on New World machines. The New World architecture was developed for the Macintosh Network Computer, an unrealized project that eventually contributed several key technologies to the first-generation iMac. All PowerPC Macs from the

iMac iMac is a family of all-in-one Mac desktop computers designed and built by Apple Inc. It has been the primary part of Apple's consumer desktop offerings since its debut in August 1998, and has evolved through seven distinct forms. In it ...

, the

iBook iBook is a line of laptop computers designed, manufactured, and sold by Apple Computer from 1999 to 2006. The line targeted entry-level, consumer and education markets, with lower specifications and prices than the PowerBook, Apple's higher-end ...

, the Blue and White Power Mac G3 and the Bronze Keyboard (Lombard) PowerBook G3 forward are New World ROM machines, while all previous models (including the Beige Power Mac G3 and all other beige and platinum Macs) are

Old World ROM Old World ROM computers are the Macintosh (Mac) models that use a Macintosh Toolbox read-only memory (ROM) chip, usually in a socket (but soldered to the motherboard in some models). All Macs prior to the iMac, the iBook, the Blue and White Powe ...

machines.

Intel Intel Corporation is an American multinational corporation and technology company headquartered in Santa Clara, California. It is the world's largest semiconductor chip manufacturer by revenue, and is one of the developers of the x86 seri ...

based Macs are incapable of running Mac OS 9 (or, indeed, any version of Mac OS X prior to

Tiger The tiger (''Panthera tigris'') is the largest living cat species and a member of the genus ''Panthera''. It is most recognisable for its dark vertical stripes on orange fur with a white underside. An apex predator, it primarily preys on ...

), and on these machines EFI is used instead of

Open Firmware Open Firmware is a standard defining the interfaces of a computer firmware system, formerly endorsed by the Institute of Electrical and Electronics Engineers (IEEE). It originated at Sun Microsystems, where it was known as OpenBoot, and has bee ...

, which both New World and Old World machines are based on. New World ROM Macs are the first Macs where direct usage of the

(OF) subsystem is encouraged. Previous PCI Power Macs used Open Firmware for booting, but the implementation was not complete; in these machines OF was only expected to probe PCI devices, then immediately hand control over to the Mac OS ROM. Because of this, versions 1.0.5 and 2.x had several serious bugs, as well as missing functionality (such as being able to load files from a HFS partition or a

TFTP Trivial File Transfer Protocol (TFTP) is a simple lockstep File Transfer Protocol which allows a client to get a file from or put a file onto a remote host. One of its primary uses is in the early stages of nodes booting from a local area netwo ...

server). Apple also set the default input and output devices to (the modem port on beige Macs), which made it difficult for normal users to get to Open Firmware; to do so it was necessary to either hook up a terminal, or change the Open Firmware settings from inside Mac OS using a tool such as ''Boot Variables'' or Apple's ''System Disk''. The New World ROM introduced a much-improved version of the Open Firmware interpreter, version 3.0, which added many missing features, fixed most of the bugs from earlier versions, and had the capability to run CHRP ''boot scripts''. The Toolbox ROM was embedded inside a CHRP script in the System Folder called "Mac OS ROM", along with a short loader stub and a copy of the

Happy Mac The classic Macintosh startup sequence includes hardware tests which may trigger the startup chime, Happy Mac, Sad Mac, and Chimes of Death. On Macs running macOS Big Sur or later the startup sound is enabled by default, but can be disabled by ...

icon suitable for display from Open Firmware. Once the ROM was loaded from disk, the Mac boot sequence continued as usual. As before, Open Firmware could also run a binary

boot loader A bootloader, also spelled as boot loader or called boot manager and bootstrap loader, is a computer program that is responsible for booting a computer. When a computer is turned off, its softwareincluding operating systems, application code, a ...

, and version 3.0 added support for

ELF An elf () is a type of humanoid supernatural being in Germanic mythology and folklore. Elves appear especially in North Germanic mythology. They are subsequently mentioned in Snorri Sturluson's Icelandic Prose Edda. He distinguishes "ligh ...

objects as well as the

XCOFF XCOFF, for "eXtended COFF", defined by IBM and used in AIX, is an improved and expanded version of the COFF object file format. Early versions of the PowerPC Macintosh also supported XCOFF, as did BeOS. XCOFF additions include the use of CSEC ...

files versions 1.0.5 and 2.0 supported. Also, version 3.0 (as well as some of the last releases of version 2.x, starting with the PowerBook 3400) officially supported direct access to the Open Firmware command prompt from the console (by setting the ''auto-boot?'' variable to ''false'' from Mac OS, or by holding down --- at boot). One major difference between Old World ROM Macs and New World ROM Macs, at least in Classic Mac OS, is that the Gestalt selector for the machine type is no longer usable; all New World ROM Macs use the same mach ID, 406 decimal, and the actual machine ID is encoded in the "model" and "compatible" properties of the root node of the Open Firmware device tree. The New World ROM also sets the "compatible" property of the root node to "MacRISC2" (machines that can boot Classic Mac OS using "Mac OS ROM") or "MacRISC3" (machines that can only boot

or another

Unix-like A Unix-like (sometimes referred to as UN*X or *nix) operating system is one that behaves in a manner similar to a Unix system, although not necessarily conforming to or being certified to any version of the Single UNIX Specification. A Unix-li ...

system). It is somewhat easier to boot a non-Mac-OS operating system on a New World system, and indeed OpenBSD's bootloader only works on a New World system. The simplest way to distinguish a New World ROM Mac is that it will have a factory built-in

USB Universal Serial Bus (USB) is an industry standard that establishes specifications for cables, connectors and protocols for connection, communication and power supply (interfacing) between computers, peripherals and other computers. A broad ...

port. No Old World ROM Mac had a USB port as factory equipment; instead, they used ADB for keyboard and mouse, and mini-DIN-8 "modem" and "printer" serial ports for other peripherals. Also, New World ROM Macs generally do not have a built-in

floppy drive A floppy disk or floppy diskette (casually referred to as a floppy, or a diskette) is an obsolescent type of disk storage composed of a thin and flexible disk of a magnetic storage medium in a square or nearly square plastic enclosure lined w ...

References

* *

External links

The Mac ROM Enters a New World
Apple's original New World ROM documentation {{Mac OS MacOS Macintosh operating systems Macintosh firmware