Quote - [It's information I read about 10 years ago. It's where your BIOS used to be stored, so you got me wondering-- I had to go on the internet Google.com with the statement Windows BIOs Ram Allocation-the information is from the Mini White Paper on HP workstations.  the BIOS takes up about 512KB starting from the very top address and it allocates blocks for IO cards, networking, PCI hubs, bus bridges, PCI express and video/graphics cards with the largest block of address allocated for the Video Card.  To me that means housekeeping.

 

That isn't really applicable any more since the transition to 32-bit operating systems - if you still use Windows 95/98 (and some people do!) then it can affect you.  It used to be that the first 1MB of memory was laid out in a very specific way, as you say some of it claimed and locked out by hardware, and users had to work it like a puzzle to get all their drivers and applications to fit.  Certain programs relied on "low memory" (that first 1MB) in order to run, for things like register space.  Since 32-bit operating systems (Windows NT / Advanced Server and later) that's gone by the wayside.  Nowadays the operating system lets your applications grab memory from any block that is free regardless of where it is, up to 3GB.  If low memory still has any real significance I'm not aware of it (and I'm certainly not aware of everything!)

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