sors, it is an extremely complex microprocessor. The MC68020 operates in two modes, these are the user mode(for application programs) or thesupervisor mode (the operating system and other special functions) (Mitchell, 155). The user and supervisor modes all have there own specific registers to operatetheir functions. The user programming has 17 32-bit address registers, and an 8-bit register (Mitchell, 155). Then the supervisor pro- gramming has three 32-bit, an8-bit and two 3-bit registers for small miscellaneous functions (Mitchell, 155). All of these registers within the two modes are split up into different groups whichwould hold different information as usual, but this set up of registers gives the microprocessors a 20 32-bit information storing capacity. The next family ofmicroprocessor is Intels 80386 and 80486 families. The 80386 and 80486 were mostly over all better then the other microprocessors being made by the differentcompanies in the industry at this time, simply because Intel is now the leading microprocessor producer in todays market. The 80386 was a product that evolvedfrom Intels very first microprocessor, the 8-bit 8080 (Mitchell, 85). Then next came the earlier mentioned 16-bit 8086. The reason why Intel did so well in themarket for microprocessors was because every microprocessor that they made was compatible with the previous and future (Mitchell, 85). This means that if a pieceof software worked on the 8080 then it worked on the future microprocessors and vice-a- versa. Not only did Intel look forward but they looked back. The maindifference between the 80386 and the other 32-bit microprocessors is the added feature of a bar- rel shifter (Mitchell, 88). The barrel shifter allowed information toswitch places mul- tiple times in the registers within a single cycle (Mitchell, 88). The microprocessor contains 8 general purpose 32-bit registers, but with the barrelshifter that is increased to the equivalent of a 64-bi...
