Sony M720 MBX-182 REV 1.0 Motherboard Schematic Circuit Diagram
Sony M720 MBX-182 REV 1.0 Motherboard Schematic Circuit Diagram
PC Processor Mode - IA-32 Mode (32-Bit)
Then there was the 386, which was the first 32-bit CPU in the PC industry. A whole new 32-bit instruction set might be executed on this microprocessor. A 32-bit operating system and a 32-bit application were required to fully use the 32-bit instruction set. The protected mode was the name given to this new 32-bit mode, which refers to the fact that software applications operating in it are protected from overwriting each other in memory. Because an incorrect application can't readily affect other programs or the operating system, such protection makes the system far more crash-proof. A crashed application can also be terminated while the rest of the system continues to function normally.
Intel sensibly included a backward-compatible real mode into the 386, knowing that new OSs and programs that make use of the 32-bit protected mode would take time to build. This allowed it to run 16-bit operating systems and programs without modification. It performed excellent, far faster than any previous chip. That was sufficient for the majority of individuals. They were not adamant about getting new 32-bit applications. All they wanted was for their current 16-bit program to operate faster. Unfortunately, this meant that the chip was never in the 32-bit protected mode, and all of the capabilities of that mode were ignored.
