direct hardware access

[flash flash@xxxxxxxx]

Y'all,

Patricia wrote:
≪
If the opsys could
always  we probably
wouldn't be able to run XyWrite. Isn't the fact that it does access the
hardware directly what made it so blazingly fast in the days of 8 MHz
PCs with 64K of RAM?≫

I think what HAL does for pre-HAL DOS apps is to create a simulated
environment for them in which they _think_ they are getting direct
hardware access but aren't really. Of course, there may be holes or
loops in HAL which cause some pre-HAL apps to lock horns with the OS
anyway. The thing about programs such as packet analysers written after
HAL which really _do_ need direct access is that they don't tolerate
simulated direct access.

HAL was introduced in NT, and if Patricia is still running 9x, then some
older DOS programs probably _are_ interfering with the OS on the issue
of direct hardware access, such as keyboard assignments. That is why
Patricia is getting hard reboots with blank-screens; HAL was invented to
redress just this case.

I'm not sure that direct access to hardware was why Xy was blazingly
fast; in Win9x days, lots of programs had direct hardware access and
weren't blazingly fast. I thought it was because Xy was efficiently
written, used memory efficiently, and made no concessions to the
buzzers-&-bells GUI mentality of MS-Oriface. Maybe I'm wrong about that.

≪MD FL≫