History
The design objective for MacWorks Plus was 100% compatibility with software that ran on the Macintosh Plus, which at the time was Apple's flagship product. This was a technically challenging goal because other than sharing the same Motorola 68000 processor, the underlying hardware architectures of the two systems were radically different. In order to understand how MacWorks Plus worked, it is easiest to divide the discussion into three areas: hardware interface, memory model and bootstrap protocol. These were the hardware-dependent aspects of the classic Mac OS at the time. The simplest method of transporting the Mac OS to another machine was to emulate them completely. Once achieved, the much larger hardware-independent code in the 128K ROM could execute with no modification. This is what was done with MacWorks Plus.
The goal was made possible by the existence of a hardware abstraction layer in the Macintosh Toolbox in the original Macintosh ROM, and a hardware Memory Management Unit (MMU) in the Lisa. Through a complete package of device drivers that fully implemented the Macintosh Toolbox Application Programming Interface (APIs), MacWorks Plus essentially tricked the 128K ROM code into thinking it was running on an actual Macintosh. It was also necessary to completely simulate the memory address space of a Macintosh Plus, including the behavior of certain illegal addresses that were deliberately exploited by certain applications (primarily games). Fortunately, while the Macintosh memory manager circuitry was not programmable, the Lisa featured a fully programmable hardware MMU which was a legacy of the minicomputer roots of its designers. Finally, bootloaders were written for all available floppy disk and hard disk models that were compatible with the Lisa.
MacWorks Plus consisted of some 23,000 lines of source code for the Lisa-dependent hardware interface and bootstrap code, plus an image of the 128K ROM that was licensed from Apple. It also included a standalone installer and a Control Panel that enabled a user to adjust certain Lisa specific features from inside the Mac OS user interface.
OS-9 is a family of real-time, process-based, multitasking, multi-user operating systems, developed in the 1980s, originally by Microware Systems Corporation for the Motorola 6809 microprocessor. It was purchased by Radisys Corp in 2001, and was purchased again in 2013 by its current owner Microware LP.
Lisa is a desktop computer developed by Apple, released on January 19, 1983. It is one of the first personal computers to present a graphical user interface (GUI) in a machine aimed at individual business users. Development of the Lisa began in 1978, and it underwent many changes during the development period before shipping at US$9,995 with a five-megabyte hard drive. Lisa was affected by its high price, insufficient software, unreliable Apple FileWare floppy disks, and the immediate release of the cheaper and faster Macintosh. Only 10,000 Lisas were sold in two years.
The Macintosh Plus computer is the third model in the Macintosh line, introduced on January 16, 1986, two years after the original Macintosh and a little more than a year after the Macintosh 512K, with a price tag of US$2,599. As an evolutionary improvement over the 512K, it shipped with 1 MB of RAM standard, expandable to 4 MB, and an external SCSI peripheral bus, among smaller improvements. Originally, the computer's case was the same beige color as the original Macintosh, Pantone 453; however, in 1987, the case color was changed to the long-lived, warm gray "Platinum" color. It is the earliest Macintosh model able to run System Software 5, System 6, and System 7.
Historically, the classic Mac OS used a form of memory management that has fallen out of favor in modern systems. Criticism of this approach was one of the key areas addressed by the change to Mac OS X.
Inside Macintosh is the title of the developer documentation manuals published by Apple Computer, documenting the APIs and machine architecture of the Macintosh computer.
System 7, codenamed "Big Bang", and also known as Mac OS 7, is a graphical user interface-based operating system for Macintosh computers and is part of the classic Mac OS series of operating systems. It was introduced on May 13, 1991, by Apple Computer, Inc. It succeeded System 6, and was the main Macintosh operating system until it was succeeded by Mac OS 8 in 1997. Features added with the System 7 release included virtual memory, personal file sharing, QuickTime, QuickDraw 3D, and an improved user interface.
The Macintosh 512Kenhanced (512Ke) was introduced in April 1986 as a cheaper alternative to the top-of-the-line Macintosh Plus, which had debuted three months previously. It is the same as the Macintosh 512K but with the 800K disk drive and 128K of ROM used in the Macintosh Plus. Like its predecessors, it has little room for expansion. Some companies did create memory upgrades that brought the machine up to 2 MB or more.
The Macintosh SE is a personal computer designed, manufactured, and sold by Apple Computer, from March 1987 to October 1990. It marked a significant improvement on the Macintosh Plus design and was introduced by Apple at the same time as the Macintosh II.
The Macintosh 128K, originally released as the Apple Macintosh, is the original Apple Macintosh personal computer. Its beige case consisted of a 9 in (23 cm) CRT monitor and came with a keyboard and mouse. It played a pivotal role in establishing desktop publishing as a general office function. A handle built into the top of the case made it easier for the computer to be lifted and carried. It had an initial selling price of US$2,495. The Macintosh was introduced by the now-famous US$370,000 television commercial directed by Ridley Scott, "1984", which aired on CBS during the third quarter of Super Bowl XVIII on January 22, 1984. Sales of the Macintosh were strong from its initial release on January 24, 1984, and reached 70,000 units on May 3, 1984. Upon the release of its successor, the Macintosh 512K, it was rebranded as the Macintosh 128K. The computer's model number was M0001.
The Macintosh 512K is a personal computer that was designed, manufactured and sold by Apple Computer, inc. from September 1984 to April 1986. It is the first update to the original Macintosh 128K. It was virtually identical to the previous Macintosh, differing primarily in the amount of built-in random-access memory. The increased memory turned the Macintosh into a more business-capable computer and gained the ability to run more software. It is the earliest Macintosh model that can be used as an AppleShare server and, with a bridge Mac, communicate with modern devices.
Macintosh XL is a modified version of the Apple Lisa personal computer made by Apple Computer, Inc. In the Macintosh XL configuration, the computer shipped with MacWorks XL, a Lisa program that allowed 64 K Macintosh ROM emulation. An identical machine was previously sold as Lisa 2/10 with the Lisa OS only.
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 components such as QuickDraw, responsible for drawing onscreen graphics, and the Menu Manager, which maintain data structures describing the menu bar. As the original Macintosh was designed without virtual memory or memory protection, it was important to classify code according to when it should be loaded into memory or kept on disk, and how it should be accessed. The Toolbox consists of subroutines essential enough to be permanently kept in memory and accessible by a two-byte machine instruction; however it excludes core "kernel" functionality such as memory management and the file system. Note that the Toolbox does not draw the menu onscreen: menus were designed to have a customizable appearance, so the drawing code was stored in a resource, which could be on a disk.
Old World ROM computers are the Macintosh (Mac) models that use a Macintosh Toolbox read-only memory (ROM) chip, usually in a socket. All Macs prior to the iMac, the iBook, the Blue and White Power Mac G3 and the Bronze Keyboard (Lombard) PowerBook G3 use Old World ROM, while said models, as well as all subsequent models until the introduction of the Intel-based EFI Models, are New World ROM machines. In particular, the Beige Power Mac G3 and all other beige and platinum-colored Power Macs are Old World ROM machines. In common use, the "Old World" designation usually applies to the early generations of PCI-based "beige" Power Macs, but not the older Motorola 68000-based Macs; however, the Toolbox runs the same way on all three types of machines.
MacWorks XL was an Apple Lisa computer program which shipped with the Macintosh XL. It allowed 64K Apple Macintosh ROM emulation so the Macintosh XL could run classic Mac OS programs.
The original Macintosh was a relatively simple machine, now of interest for its simplicity and for the fact that it was the first computer produced by Apple under the name Macintosh. The Macintosh used standard off-the-shelf components to the greatest extent possible, achieving a moderate price point by mixing complex LSI chips, readily customizable programmable array logic, and off-the-shelf components.
The Amiga computer can be used to emulate several other computer platforms, including legacy platforms such as the Commodore 64, and its contemporary rivals such as the IBM PC and the Macintosh.
The Mac OS nanokernel is an operating system kernel serving as the basis of most PowerPC based system software versions 7 through 9 of the classic Mac OS, predating Mac OS X.
The Macintosh Hard Disk 20 was the first hard drive developed by Apple Computer specifically for use with the Macintosh 512K. Introduced on September 17, 1985, it was part of Apple's long-awaited solution toward completing the Macintosh Office announced in January 1985. It would be over a year more before Apple would release the file server software AppleShare that would link all of the hardware together. By that time the SCSI interface introduced on the Macintosh Plus in January 1986, would accommodate far faster and more efficient hard drives, rendering the Hard Disk 20 virtually obsolete.
The Macintosh External Disk Drive is the original model in a series of external 3+1⁄2-inch floppy disk drives manufactured and sold by Apple Computer exclusively for the Macintosh series of computers introduced in January 1984. Later, Apple would unify their external drives to work cross-platform between the Macintosh and Apple II product lines, dropping the name "Macintosh" from the drives. Though Apple had been producing external floppy disk drives prior to 1984, they were exclusively developed for the Apple II, III and Lisa computers using the industry standard 5+1⁄4-inch flexible disk format. The Macintosh external drives were the first to widely introduce Sony's new 3+1⁄2-inch rigid disk standard commercially and throughout their product line. Apple produced only one external 3+1⁄2-inch drive exclusively for use with the Apple II series called the Apple UniDisk 3.5.
The classic Mac OS is the series of operating systems developed for the Macintosh family of personal computers by Apple Inc. from 1984 to 2001, starting with System 1 and ending with Mac OS 9. The Macintosh operating system is credited with having popularized the graphical user interface concept. It was included with every Macintosh that was sold during the era in which it was developed, and many updates to the system software were done in conjunction with the introduction of new Macintosh systems.
