Mail Archives: djgpp/1997/08/10/11:10:44
On Sun, 3 Aug 1997, Gurunandan R. Bhat wrote:
> The FAQ that I have (ver 2.10) says that the limit of the segment
> pointed to by _dos_ds is 1MB and then in a footnote continues:
>
> ...*Original* version of DJGPP 2.01 makes limit of _dos_ds be 4GB....
>
> (emphasis mine)
> For my DJGPP setup (most recent, or so I thought), I get
>
> __dpmi_get_segment_limit(_dos_ds) = ffffffff
>
> Does this mean that I have the "Original" version as opposed to the "Later"
I have wondered how much time would it take for somebody to pay
attention, and who would that person be.
Here's the story behind this: the fact that `_dos_ds' has a 4GB limit
became known to me shortly before FAQ 2.10 was released. During a
discussion, DJ Delorie explained that he enlarged it from 1MB because
too many people wanted it be enlarged for all kinds of memory-mapped
devices. The footnote that you cite was written in the hope that this
limit will be set back to 1MB in a later release. But since DJGPP was
not updated since then, the latest DJGPP version still has a 4GB-large
limit. IMHO, this is a Bad Thing, because it allows a program to
corrupt every address in sight, while the benefits are almost none:
most DPMI hosts won't allow accesses to hardware devices mapped
outside the 1MB range without special DPMI calls.
So, to summarize: there is no ``Later'' version of DJGPP v2.01.
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