The Sinclair QL stands for Quantum Leap. It is a high-end computer launched by Sinclair Research in 1984. It features the Motorola 68008 CPU running at 7.5MHz. This processor is part of the 68000 family, has 32-bit internal registers, but an 8-bit external data bus.

The code name for the QL was ZX83, and the original idea was for this computer to be a portable one, but the specifications were too ambitions for the computer to be portable. The QL had a clock speed comparable to that of the Macintosh, Atari ST and Amiga computers, the 8-bit data-bus limited the performance. At the time of the launch, the QL was not ready for production. Sinclair took orders and promised delivery within 28 days, but failed to do so, this caused criticism and put a dent in consumer confidence of the company.

The QL also suffered from initial problems with their Micro-drives. These problems were rectified, but the damage it had caused to Sinclair's reputation could not be undone. The QL failed to sell in large numbers and production was suspended in 1985 due to lack of demand. When Amstrad acquired Sinclair's computer product lines in 1986, the QL was officially discontinued. Even if the QL had been more reliable and would not have suffered delays, the business market was already invested in the IBM PC platform, and the QL would have had an uphill battle to make a dent in this market.

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