Apple  Macintosh Quadra 800
apl_mac_q800

Macintosh Quadra 800

The Apple Macintosh Quadra 800 was introduced in 1993, along the Macintosh Centris computers (Centris 650, which is the same as the Quadra 650). It has a Motorola 68040 CPU running at 33MHz, enhanced video, and new interleaved RAM that ran at 70ns.

Is it a Quadra? An LC? A Performa?

In 1993 Apple made the decision to rename their Macintosh computers. They introduced three different product names, based on the target audiences. The result of this is that many Macintosh machines are exact duplicates of each other, but just with a different brand name.

  • Quadra line - Business Customers, sold only through Apple resellers.
  • LC line - Education market, sold primarily to schools.
  • Performa - Home consumers, sold in department and electronics stores.

Example: The Macintosh Quadra 605 is the same computer as the Macintosh LC 475 and the Macintosh Performa 475.

Motorola 68000 CPU Family

The Motorola 68000 is a 16/32-bit microprocessor that was first released in 1979. It was widely used in computers and other electronic devices during the 1980s and early 1990s. The 68000 was known for its advanced architecture, which included a 32-bit internal bus and a 24-bit address bus, allowing it to access up to 16 megabytes of memory. This made it more powerful than many other processors of its time, such as the Intel 8086 and Zilog Z80. It was also designed to be highly modular and expandable, with a large number of on-chip and off-chip peripherals.

Some of the most famous and successful computers that used the 68000 was the Commodore Amiga and the Atari ST, both of which were popular in the home and personal computer markets. Additionally, it was also used in workstations, such as the Sun 3 and Apollo DN3000, and in a wide variety of embedded systems and industrial control systems. The 68000 was also used in the Macintosh, the first model of the Macintosh was powered by a Motorola 68000 CPU. The processor was eventually succeeded by the 68020 and 68030, which offered improved performance and additional features.

The 68000 has a 32-bit instruction set, with 32-bit registers and a 16-bit internal data bus. The address bus is 24-bit and does not use memory segmentation, making it easier to address memory. There are three ALU's (Arithmetic Logic Unit), two for calculating addresses, and one for data, and the chip has a 16-bit external address bus.

The 68000 architecture was expanded with 32-bit ALUs, and caches. Here is a list with some 680x0 versions and their major improvements:

  • 68010 - Virtual memory support
  • 68020 - 32-bit ALU & Instruction Cache
  • 68030 - On-Chip MMU, 2x 256 byte cache
  • 68040 - 2x 4K Cache, 6 stage pipeline, FPU
  • 68LC040 - No Floating Point Unit (FPU)
  • 68060 - 2x 8K Cache, 10 stage pipelinet

Released 1992 Country United States Brand Type APPLE Macintosh LC & Quadra Name Macintosh Quadra 800 CPU Class 68000 CPU Motorola 68040 @33MHz Memory 24MB RAM, 136MB Max, 1MB VRAM Sound Chip TTL Logic for PWM Sound 8-bit Pulse-width modulation Display Chip none Display 640x480 16-bit color
1152x780 max
Sprites none System OS Mac System 7.1
Related Systems
 
Apple Series I
 
Apple Series II
 
Apple Series III
 
Apple Macintosh
 
Apple Macintosh II
 
Apple Macintosh LC & Quadra
 
Macintosh  Quadra 800 (1992)
 
Apple Newton
Books & Publications
 
6502 CPU
Collection of books on the 6502 and compatible CPUs
 
Apple Macintosh
Books about the Apple Macintosh, the first mass-market personal computer with a graphical user interface.
Magazines & Serials
 
InCider and A+
InCider Magazine for Apple Computers, later fused with A+
 
Peeker Magazine
Peeker, a German language magazine for Apple Computer users.
World Wide Web Links
 
Wikipedia: Motorola 68000 CPU Family
WikiPedia page on the Motorola 68000 series of processors