osmoviita@cc.helsinki.fi (06/18/91)
In article <1991Jun17.020201.14746@proto.com>, doug@proto.com (Doug Huffman) writes: > > There are two separate DOS extenders. One is for the 286 and is licensed > from Rational Systems. The resultant executable will (of course) run on > 386 machines. The other is for the 386 and will run only on 386's and 486's > and is licensed from me. The 386 one has a 64 MB limit under DOS and VCPI > because the BIOS returns the number of K bytes of extended memory available > in a 16 bit register, under DPMI you have less because things are different > .... (understatement of the month). > > uunet!proto!doug > doug@proto.com Only 64 MB? DJGPP has 128 MB main memory + 128 MB disk swap space! How about the virtual memory size in Your extender? And so, is DPMI only for small data forever? Kari Osmoviita osmoviita@cc.helsinki.fi
doug@proto.com (Doug Huffman) (06/19/91)
osmoviita@cc.helsinki.fi writes: >In article <1991Jun17.020201.14746@proto.com>, doug@proto.com (Doug Huffman) writes: >> >> and is licensed from me. The 386 one has a 64 MB limit under DOS and VCPI >> because the BIOS returns the number of K bytes of extended memory available >> in a 16 bit register, under DPMI you have less because things are different >Only 64 MB? DJGPP has 128 MB main memory + 128 MB disk swap space! >How about the virtual memory size in Your extender? And so, is DPMI only >for small data forever? I do not know how it can allocate 128 MB. How does it know this much memory is available? The BIOS doesn't handle this. Send email on this or post in comp.os.msdos.programmer, this is out of line for comp.lang.c Under DPMI the amount of memory available is host dependant. With my extender I take 3/4 of the memory reported by the DPMI host. My extender will handle up to 3 GBytes under DPMI (provided the host reported 4 GBytes available). My extender does not current provide virtual memory directly, this is handled by the DPMI host. -- uunet!proto!doug doug@proto.com