nadel@TAURUS.BITNET (05/09/90)
I was wondering if any of you noticed this too:
I played around with my config file, trying to figure out why it consumed
55K when I only load drivers 12K long. Here are some results:
1. No drivers 16K
2. FastBios driver alone 49K
3. Everything but FastBios 54K
4. Everything 55K
Simple calculation reveales that the FastBios driver takes 55K-54K = 1K.
So how come just loading it takes 49K-16K = 33K? It seems like just loading
one driver is enough to blow away your memeory, but many drivers don't do
more damage then one!
Hope for an answer.dixon@sagittarius.crd.ge.com (walt dixon) (05/10/90)
In a previous article, nadel@TAURUS.BITNET writes:
. I was wondering if any of you noticed this too:
. I played around with my config file, trying to figure out why it consumed
.55K when I only load drivers 12K long. Here are some results:
. 1. No drivers 16K
. 2. FastBios driver alone 49K
. 3. Everything but FastBios 54K
. 4. Everything 55K
. Simple calculation reveales that the FastBios driver takes 55K-54K = 1K.
.So how come just loading it takes 49K-16K = 33K? It seems like just loading
.one driver is enough to blow away your memeory, but many drivers don't do
.more damage then one!
I'm not exactly sure how the size of the drivers is arrived at. The size
of the driver file? When DOS calls a device drriver at its initialization
point, basically all available memory belongs to the driver. The driver
decides how much memory it needs by setting a value (break address) in
a data structure (request header). Typically drivers grab extra memory
for buffers. Of course the driver is free to use memory in any way
it deems fit. It is also common for a driver writer to put initialization
code at the end of the driver. This code might set up a device, parse
a line from config.sys, etc. This memory can be recycled after the
initialization completes. It is possible for a driver to use less
memory than one would suspect based on file size.
The bottom line is the correlation between memory usage and file size
is loose at best.
Walt Dixon {internet: dixon@crd.ge.com }
{us mail: ge-crd }
{ po box 8 }
{ schenectady, ny 12301 }
{phone: 518-387-5798 }
Walt Dixon dixon@crd.ge.com