There are two models of the Commodore Amiga 4000:

• A4000/040 - released October 1992 using Motorola 68040
• A4000/030 - released April 1993 using Motorola 68EC030

The Amiga 4000 was an upgrade to the A3000 and introduced the Advanced Graphics Architecture chipset with enhanced graphics. The SCSI hard drive interface was replaced with the Parallel ATA system. The system came in two cases, first the desktop-case and later an expanded tower case that offers more room for expansion.

The AGA chipset is part of Commodore's third generation Amiga chipset and has improved graphical abilities. The palette is expanded from 12-bit color depth to 24-bit. This increased the number of possible colors from 4096 to 16.8million. There are also new HAM-8 color modes, with 262,144 colors on screen simultaneously. The AGA also has improved sprite capacity and an overall performance increase.

Expansion ports:

• External:
  • 2 DE-9 ports for joystick, mouse or light-pen
  • 25-pin RS323 serial port
  • 25-pin parallel Centronics port
  • 2 RCA Audio Out
  • 6-pin mini DIN keyboard
  • DB-23F Floppy disk drive port
  • Analog RGB video out
• Internal:
  • Internal ATA controller
  • 4 100pin 32-bit internal Zorro III slots
  • 1 AGA video slot
  • 3 16-bit ISA slots
  • 1 200-pin CPU expansion port
  • 4 72-pin SIMM memory slots

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

Source: WikiPedia - Motorola 6800
Source: WikiPedia - 68000 Series