From: Charles Sandmann <sandmann AT new-orleans DOT NeoSoft DOT com>
Subject: Re: v2 & descriptors
To: dannys AT seas DOT ucla DOT edu
Date: Sun, 27 Nov 1994 09:29:27 -0600 (CST)
Cc: djgpp AT sun DOT soe DOT clarkson DOT edu

> First of all, where can I find info on when v2.0 will come out and
> what enhancements it will have?

It will come out when it is finished, hopefully 1Q95.  New features:
faster, small low memory requirements (GO32 goes away), single API
for programming (DPMI), signals, ansi/posix, etc.

> I'm currently mainly interested in being able to manipulate the GDT
> and LDT (more assembly here than C, I guess).  Anyway, I'm trying
> to write a decent multitasking kernel.  Nothing spectacular, just
> something that works.  I heard from somewhere that the current
> version doesn't support modifying of the LDT, but that this was
> planned for v2.0.  Is this correct?

There is a patch floating around which allows you to use the DPMI
selector services in V1.12 with only GO32.  V2 comes with a free DPMI
which I can also let you have a test copy of.  You can't mess with
the GDT at all.

> I'm still just beginning on this kernel, so if anyone can give
> me any pointers, I'd be grateful.

The handling of HW interrupts under DPMI isn't very convenient, so
causing a task switch on timer interrupts is difficult to do correctly.

> Also, while I'm on this thread, where can I find information on how
> the DJGPP extender handles the low-level stuff?  I don't have
> a particular question in mind at the moment, aside from the ones 
> just mentioned.  Are there docs for this, or do I have to rummage
> around the source?

Read the source, and drop me a message if you are stumped.