![]() ![]() ![]() you're counting 16, 32, 48kb, etc and using a base-16 nomenclature to label those rows so you'll get a row like A000 - A3FF. Each layer is addressed using hexadecimal, which may sound spooky but it just means instead of counting 10, 20, 30kb, etc. Now this stack is divided up into 16kb layers. Doesn't matter how much total RAM you have though, since everybody has the same 640Kb at the bottom of the stack. So now that we've reminisced in the past that most of us never experienced, here's the deal.Īll the RAM in your old computer is like a big stack of bricks, starting at the ground and going up. Windows 95 may seem similar but in many ways it was just another extension of DOS, like Windows 3.1 was and lots of software was still tied to those pesky DOS limitations. ![]() It would take decades before Windows 98 would finally dispel with DOS dependencies altogether and dynamically manage all the memory for you. Adding more to that was fine later on and as we got into the 286 and 386 architecture we definitely needed it, but the heritage of the 8086 architecture and how DOS utilized those lower memory blocks remained. You only had so many 'bits' to work with and memory addressing could only count so high with those bits so it was impractical to use anything more than 1 MB of memory with these simple CPUs. The problem was the technology at the time. To be honest my history knowledge gets fuzzy this far back but DOS at least has been around since well into the early 80s and the 8086 the future Intel chip architectures were based upon has been around even earlier than that, as early as the 70s so way back then somebody decided that it would be convenient to place certain hardware ROMs in specific places in memory, which then formed the footprint in memory we know as conventional memory or the first 640kb. ![]()
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