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Great read. Are there technical reasons why Microsoft didn't release a Protected Mode version of MS-DOS in the 80s, or was it just a case of trying to push use
by thought_alarm 10y ago
Great read.
Are there technical reasons why Microsoft didn't release a Protected Mode version of MS-DOS in the 80s, or was it just a case of trying to push users and developers to OS/2 and Windows?
It seems like such a no-brainer, especially since MS-DOS provided so few services to applications anyway. You have MS-DOS 8 and MS-DOS 16, and you let the user choose which version to boot into, or you automatically kick over to MS-DOS 16 when a Protected Mode app is launched. It seems a lot saner than forcing users to muck around in config.sys.
That people were forced to deal with the memory limitations of the 8088 PC well into the 90s is just bananas.
- stickfigure 10y agoIt's not quite that simple. DOS is not like what we think of as an OS today; more like some libraries that sit in RAM at known addresses plus a loader barely smart enough to transfer data from disk to RAM and start execution. All the intelligence is in the application program itself. And those programs were still stuck with 20-bit pointers. It wasn't just a question of rewriting the OS, it was also a question of rewriting all the application software. Which eventually happened.
- digi_owl 10y agoAnd why I half-jokingly consider unikernels "DOS in a can".
- throwaway91111 10y agoNothing bars unikernels from running their code in protected memory as the sole non-ring-0 proc.
- JdeBP 10y agoMicrosoft did. It was simply inside 386 Enhanced Mode DOS+Windows. By the way, MS/PC-DOS provided quite a lengthy list of services to applications. Have a look at DOS parts of Ralf Brown's Interrupt List some time.