New World ROM computers are

Macintosh Mac is a brand of personal computers designed and marketed by Apple Inc., Apple since 1984. The name is short for Macintosh (its official name until 1999), a reference to the McIntosh (apple), McIntosh apple. The current product lineup inclu ...

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, Unix-based operating system developed and marketed by Apple Inc., Apple since 2001. It is the current operating system for Apple's Mac (computer), Mac computers. With ...

not requiring the availability of the Toolbox, this allowed ROM sizes to shrink dramatically (typically from to ), and facilitated the use of

flash memory Flash memory is an Integrated circuit, electronic Non-volatile memory, non-volatile computer memory storage medium that can be electrically erased and reprogrammed. The two main types of flash memory, NOR flash and NAND flash, are named for t ...

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 the eighth major release of the classic Mac OS operating system for Macintosh computers, 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 ...

and

Mac OS 9 Mac OS 9 is the ninth and final major release of the classic Mac OS operating system for Macintosh computers, made by Apple Computer. Introduced on October 23, 1999, it was promoted by Apple as "The Best Internet Operating System Ever", highlight ...

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 PowerPC (with the backronym Performance Optimization With Enhanced RISC – Performance Computing, sometimes abbreviated as PPC) is a reduced instruction set computer (RISC) instruction set architecture (ISA) created by the 1991 Apple Inc., App ...

Macs from the

iMac The iMac is a series of all-in-one computers from Apple Inc., sold as part of the company's Mac (computer), Mac family of computers. First introduced in 1998, it has remained a primary part of Apple's consumer desktop offerings since and evol ...

, 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- ...

, the Blue and White Power Mac G3 and the Bronze Keyboard (Lombard) PowerBook G3 forward are New World ROM machines, while all previous PowerPC models (including all PCI-based Power Macs such as the Beige/Platinum Power Mac G3 and some NuBus-based Power 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, and Delaware General Corporation Law, incorporated in Delaware. Intel designs, manufactures, and sells computer compo ...

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 a large Felidae, cat and a member of the genus ''Panthera'' native to Asia. It has a powerful, muscular body with a large head and paws, a long tail and orange fur with black, mostly vertical stripes. It is ...

), and on these machines

UEFI Unified Extensible Firmware Interface (UEFI, as an acronym) is a Specification (technical standard), specification for the firmware Software architecture, architecture of a computing platform. When a computer booting, is powered on, the UEFI ...

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 PCI may refer to: Business and economics * Payment card industry, businesses associated with debit, credit, and other payment cards ** Payment Card Industry Data Security Standard, a set of security requirements for credit card processors * Prov ...

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 HFS may refer to: Businesses and organisations * Croatian Film Association () * Hellenic Fire Service, Greece * Hospitality Franchise Systems, US Computing * Hierarchical file system, a system for organizing directories and files * Hierarchica ...

partition or a

TFTP The Trivial File Transfer Protocol (TFTP) is a simple Lockstep (computing), lockstep communication protocol for transmitting or receiving files in a client-server application. A primary use of TFTP is in the early stages of nodes booting on a l ...

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 Macintosh startup sequence for Apple Macintosh (or Mac) computers includes hardware tests and diagnostics which can trigger the startup chimes and/or other instances of success or failure of the startup routines. The startup sequence provid ...

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 bootstrap loader, is a computer program that is responsible for booting a computer and booting an operating system. If it also provides an interactive menu with multiple boot choices then it's o ...

, and version 3.0 added support for

ELF An elf (: elves) is a type of humanoid supernatural being in Germanic peoples, Germanic folklore. Elves appear especially in Norse mythology, North Germanic mythology, being mentioned in the Icelandic ''Poetic Edda'' and the ''Prose Edda'' ...

objects as well as the

XCOFF XCOFF (Extended Common Object File Format) defined by IBM and used in AIX operating system, AIX, is an improved and expanded version of the COFF (Common Object File Format) object file format.https://www.ibm.com/docs/en/aix/7.3?topic=formats-xco ...

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 The PowerBook (known as Macintosh PowerBook before 1997) is a family of Macintosh-type laptop computers designed, manufactured and sold by Apple Computer from 1991 to 2006. It was targeted at the professional market; in 1999, the line was suppl ...

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, *nix 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 Uni ...

system). It is somewhat easier to boot a non-Mac-OS operating system on a New World system, and indeed

OpenBSD OpenBSD is a security-focused operating system, security-focused, free software, Unix-like operating system based on the Berkeley Software Distribution (BSD). Theo de Raadt created OpenBSD in 1995 by fork (software development), forking NetBSD ...

'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, developed by USB Implementers Forum (USB-IF), for digital data transmission and power delivery between many types of electronics. It specifies the architecture, in particular the physical ...

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, a diskette, or a disk) is a 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 with a ...

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