From the 6502 to the 6809 - a new 'super' 6502! The 6809.

6-50 — elektor june 1982 from the 6502 to the 6809 Following the latest trend in high-speed systems, Motorola has developed a microprocessor that has an internal 16- bit structure. One of the reasons why the 6809 is known as a "Super 6502" is that its registers have the same names as those in the 6502. The features of the two systems are in fact very similar, except that the Motorola chip is much faster and more powerful. The differ- ences in structure are shown in figure 1. allow programs to be stored in any area of memory, without having to rely on absolute addresses and without having to alter a single byte. Such programs are known as "relocatable" routines. The system introduces a new addressing mode, the "program counter relative" mode. This is extremely powerful, and enables any memory location to be addressed (at a certain moment) that corresponds to the contents of the program counter. from the 6502 As the saying goes, "What you gain on the swings, you lose on the rounda...