flat assembler
Message board for the users of flat assembler.
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BAiC 14 Oct 2013, 05:59
roughly half (640k I think) of the first megabyte is available to you below the 1MB RealMode boundary. whatever is left between the boot sector and the 640k address is usually the largest contiguous block of memory in Real Mode. it's smaller but you can also use memory between 0x500 and 0x7C00 (the boot sector).
once you turn on Protected Mode (32bit) you can safely use almost all addressing space in those 32bits. Stefan _________________ byte me. |
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spandexyfronts 14 Oct 2013, 16:50
I was straying underneath the 0x500 limit you described there in real mode and wondered what was wrong. Thanks for the useful info, i'm able to 'set things in stone' and be a bit more surefooted now.
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cod3b453 14 Oct 2013, 17:14
I normally avoid the following ranges:
Code: 00000-005FF (BIOS IVT & BDA) 07C00-08C00 (boot sector) 9F000-FFFFF (BIOS EBDA, VGA MMIO, BIOS, extension/additional ROMs) ![]() |
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