9 Jul
2014
9 Jul
'14
9:24 a.m.
On Wed, Jul 09, 2014 at 10:23:32AM +0100, Peter Corlett wrote:
Somewhat curiously, it reported the full 8GB of RAM as
available, although
it's not entirely clear to me how DOS apps can make use of that short of
switching into long mode and bootstrapping a real operating system.
E11 can (for caches and RAMdisks anyway), on CPUs that support PAE (phys
addr extension). It's just like regular 32-bit paging except with four
page directories instead of one, and the page-table entries are quadwords
to hold the extra address bits (and the non-executable bit which is new
with PAE, and MS made a big deal out of supporting PAE mode in 32-bit
Windows just for that whether or not you have >4 GB of memory, since it
defeats lots of exploits).
It seems as if 32-bit API support for PAE kind of didn't happen -- wasn't
AWE32 supposed to be a thing on Win32? I couldn't make it work in real
life. And I couldn't find a Linux equivalent. So I find it funny that
if you want E11 to use the crazy amount of memory your new PC has, you have
to use the DOS (or stand-alone) version, rather than one of the OSes that
actually knows how to use all that memory. (If someone wants to set me
straight about mapping windows to 64-bit memory space from a 32-bit
program, I'd love to hear about it please.)
John Wilson
D Bit