Conrad.Bullock@comp.vuw.ac.nz (Conrad Bullock) (04/24/91)
In article <1991Apr23.083505.1964@sun1.ruf.uni-freiburg.de>, hartnegg@sun1.ruf.uni-freiburg.de (Klaus Hartnegg) writes: |> Some days ago I wrote: |> |> >I have 645k free conventional memory with Dos 3.3 and Qemm 5.11 |> with |> >several devices and TSR's installed. No, it's not a typo, I really |> have |> >645k free, it is definitively conventional memory and I am really |> running |> >Dos 3.3. |> |> First of all: I have a 386 and installed QEMM 386 and DESQview. |> Together with QEMM comes the program "optimize". I simply ran |> this program. It made some changes to my config.sys, booted twice |> and, |> voila, I had 704k conventional memory. Some of this is used |> by some TSR's and devices that can not be loaded into high memory |> (I already knew this and changed the config.sys after running |> optimize to prevent them from being loaded high as optimize wanted |> to load them). The rest (645k) is free. |> |> Sorry, I do not know precisely what is going on here but |> it has something to do with the fact that I have a 386 |> (only this processor can remap memory to all places that it |> likes to) and also it is has something to do with my hercules |> graphics card. The Hercules graphics card takes 64K of the address space from segment B000. DOS normally uses the first 640K of memory, ending at segment A000. Since the 64K area from A000-B000 is unused, QEMM can map 64K of extended memory into there, and tell DOS that it can use right up to the 704K mark. |> ... Stuff about using video RAM deleted ... It doesn't actually use the video RAM itself - QEMM can use the areas of memory which the video card doesn't take. On a VGA system, the area of memory A000-B000 is used for the graphics modes, so if you want graphics, you can't use that area for conventional memory. However, there is a 32K gap from B000-B800, and QEMM can use this for High RAM on VGA systems. Another alternative on VGA systems is to disable the use of graphics, and then QEMM can use the area of memory right up to B800, giving you 736K of 'conventional' memory. Followups to comp.sys.ibm.pc.misc. -- Conrad Bullock | Domain: conrad@comp.vuw.ac.nz Victoria University of Wellington, | or: conrad@cavebbs.gen.nz New Zealand. | Fidonet: 3:771/130 | BBS: The Cave BBS +64 4 643429