6800
Motorola's first widely produced microprocessor was the 6800, introduced in early 1974 and available in quantity late that year. The company set itself the goal of selling 25,000 units by … 展开

IBM considered the 68000 for the IBM PC but chose the Intel 8088; however, IBM Instruments briefly sold the 68000-based IBM System 9000 laboratory … 展开

Address bus
The 68000 has a 24-bit external address bus and two byte-select signals "replaced" A0. These 24 lines can … 展开

The 68EC000 is a low-cost version of the 68000 with a slightly different pinout, designed for embedded controller applications. The 68EC000 can have either a 8-bit 展开

In 1982, the 68000 received a minor update to its instruction set architecture (ISA) to support virtual memory and to conform to the Popek and Goldberg virtualization requirements. The updated chip is called the 68010. It also adds a new "loop mode" which … 展开

The standard addressing modes are:
• Register direct
• Register indirect
• PC (program counter) relative with displacement
• Absolute memory location 展开

The 68000 assembly code below is for a subroutine named strtolower, which copies a null-terminated string of 8-bit characters to a destination string, … 展开