cle. The original R2000 contained just 110,000 transistors (compared to almost 300,000 for the Intel 386), ran at 12 MHz and clocked in at an impressive 9 MIPS (six times the speed of the 386). It powered the first RISC based workstations - Digital's DECstations.MIPS stood for Microprocessor without Interlocked Pipeline Stages. In somewhat of an irony, however, pipeline interlocks had to be added back into the architecture five years later (1991) for the third generation MIPS processor, the R4000 (actually, even the R2000 had interlocks for the HI/LO register pair used by the multi-cycle multiply and divide instructions).The Intel 80386 Processor - x86 goes 32-bitThe 80386 heralded the beginning of a new age for the IBM PC. The 386 was the first 32-bit x86 processor. As such, it was capable of breaking the 640 Kb memory barrier and running software written for graphical user interfaces. The 386 introduced a 32-bit architecture while maintaining full backward compatibility with earlier x86 processors. This was accomplished by using two operating modes: "real" mode, which mirrored the segmented memory of the older x86's, and "protected" mode which took full advantage of the 386's 32-bit enhancements.The 386 began shipping in August 1986, but unfortunately it was several years before PC operating systems could make use of its 32-bit capabilities. IBM's OS/2 and Microsoft's Windows '95 were really the first 32-bit mainstream PC operating systems, and even on them most applications were still 16-bit!Compaq's Deskpro 386While IBM was busy developing its proprietary MicroChannel based PS/2 systems, clone vendors ALR and Compaq grabbed control of the x86 market by introducing the first 386-based PC's, the Access 386 and the Deskpro 386, just a couple of months after Intel began shipping the 80386 processor. This marked the end of IBM's dominance of the IBM PC market. Both 386 clone systems maintained backward compatibility with the 286-based PC...
