Re: Windows 95

[turnbull@example.com (Stephen J. Turnbull)]

>>>>> "Norihide" == Norihide Kise <s100234@example.com> writes:

    Norihide> partitions for Windows 95 and DOS/Windows 3.1 if I don't
    Norihide> mind spending money for upgrading my old DOS
    Norihide> programs. But I don't have lots of money to upgrade
    Norihide> software, should I have to partition? Also, some of the

Whether or not you have to partition depends on your hardware and
software.  Sigh.  Make sure that everything you can't reinstall from
originals is backed up, and experiment.

    Norihide> old DOS programs seem to run slowly. Plus, several DOS
    Norihide> programs, especially DOS-based games, don't display
    Norihide> graphics properly.

I would guess that the problem is that they try to go direct to the
screen.  This is not permitted under DPMI (well, actually it is, even
under Windows NT; apparently all of those "secure" OSes from MS and
IBM allow you to request a DPMI segment that is 4GB, which wraps
around and lets you access all of memory.  Shudder.  Only Linux DOSemu
has a DPMI driver that follows the standard and prohibits this).  So
these OSes must intercept those screen writes, and call the
appropriate screen drivers.  Slow.  Of course this isn't 100%
reliable.  Some programs use non-standard non-standard [sic] ways of
accessing the screen, and they won't work.

A resource that might be of some help is the DJGPP newsgroup,
comp.os.msdos.djgpp.  The issue of programming graphics under DPMI is
always under discussion there.  WARNING:  this group is for the DJGPP
port of GNU C/C++ to DOS; it is NOT a fixit group for Windows95.
Before you post on this topic, get the FAQ and search the archives
(http://www.delorie.com/) and lurk on the list a bit.  There are
probably other newgroups that would be more appropriate, but the DJGPP 
developers are really sharp.

-- 
                            Stephen J. Turnbull
Institute of Socio-Economic Planning                         Yaseppochi-Gumi
University of Tsukuba                      http://turnbull.sk.tsukuba.ac.jp/
Tennodai 1-1-1, Tsukuba, 305 JAPAN                 turnbull@example.com