[E-Lang] what is good about E?

shap@cs.jhu.edu shap@cs.jhu.edu
Thu, 26 Jul 2001 09:54:32 -0400

Ken Kahn wrote:
> Jonathan wrote:
> > Probably not. The "Direct" in "DirectX" means that DirectX has direct
> > access to the hardware. There is not a lot you can do at that point
> > other than dynamic compilation to inject sandboxing code.
> >
> It does give direct access to video, sound, and input devices but not to
> disk drives, memory (except video and sound card memory), CPUs, network
> cards, etc.

That's the spec, but to enforce it on the PC you need to do dynamic
compilation, because the devices that it *does* have access to in turn
have physical DMA access.

> I've never heard of any software abusing this direct access (other than bugs
> that cause crashes) and the benefits are large to serious gamers who get
> higher performance games than would otherwise be possible. I guess DirectX
> should be thought of as yet another bundle of capabilities that one could
> grant.

I wasn't arguing the merit of DirectX. For sure it's better than having
every game author hack video uniquely. I was only trying to express some
limitations that arise when you install software that requires direct
access to the hardware.

Actually, there is an issue that we haven't addressed: the OS vendor
probably needs to "sign off" on the upgrade; otherwise, warrantees and
support contracts can be rendered unsupportable. This isn't inherently
fatal, but there should certainly be a clear demarcation point at which
the user knows they have voided the software warranty.