mirror of
https://github.com/joncampbell123/dosbox-x.git
synced 2025-10-13 17:48:10 +08:00
78 lines
3.1 KiB
Plaintext
78 lines
3.1 KiB
Plaintext
Windows 3.1 and 3.11 can be run from DOSBox's native prompt.
|
|
However, there is one serious incompatability regarding mouse
|
|
emulation that you need to know about:
|
|
|
|
INT 33h emulation
|
|
|
|
Because of the way INT 33h emulation is written, the code will
|
|
(correctly) defer mouse event notification until IRQ 12 is
|
|
activated, BUT, it does the on-screen cursor update directly
|
|
from the Mouse event handler.
|
|
|
|
Unfortunately, this means that if you are running a protected
|
|
mode environment like Windows 3.1, the BIOS data area reads
|
|
and direct access to video RAM will happen at a time that the
|
|
Windows 3.1 is not likely to expect it, and you will get
|
|
random crashes and general instability.
|
|
|
|
The solution to this problem is to code the software cursor
|
|
redraw to happen from within IRQ 12 (where Windows and DOS
|
|
programs expect it to happen), and where Windows is likely
|
|
to virtualize IRQ 12 into virtual 8086 mode and allow the
|
|
INT 33h driver's real-mode code to do it's work properly.
|
|
|
|
Until I have this solution completed in the code, a workaround
|
|
is available if you do not intend to use DOS games in the same
|
|
virtual setup as your Windows 3.1 installation:
|
|
|
|
Open your dosbox.conf, and set int33=false (disable INT 33h
|
|
emulation). If the line doesn't exist, add int33=false under
|
|
the [dos] section of your dosbox.conf.
|
|
|
|
Disabling INT 33h emulation will resolve this conflict between
|
|
DOSBox real-mode INT 33h emulation and Windows 3.1.
|
|
|
|
--------------------------------------------------------------
|
|
|
|
Another noted problem with the PS/2 mouse and DOS "boxes" in
|
|
Windows 3.1 is that, when a DOS "box" is run in a Window,
|
|
rather than in fullscreen mode, the cursor will become very
|
|
jumpy, and in DOSBox, will likely stop responding to your
|
|
mouse input entirely until you switch away. Apparently, this
|
|
is... normal. Windows 3.1 is not very good at virtualizing
|
|
the PS/2 mouse while sharing it with the DOS "box".
|
|
|
|
If the cursor stops responding, you can try ALT+Tab to
|
|
switch away (and restore cursor responsiveness) or ALT+Space
|
|
to bring up the DOS box's system menu (taking focus away from
|
|
the DOS session restores proper mouse pointer responsiveness).
|
|
|
|
--------------------------------------------------------------
|
|
|
|
Known problems with "additional environment block size on exec"
|
|
option.
|
|
|
|
Setting "additional environment block size on exec" to 0 in your
|
|
dosbox.conf and then running Windows 3.1 can cause DOSBox-X to
|
|
crash with a "MCB chain corrupt" error message.
|
|
|
|
--------------------------------------------------------------
|
|
|
|
"kernel allocation in umb" and dynamic kernel allocation problem.
|
|
|
|
Windows 3.1 will not start if DOSBox-X is configured to put all
|
|
DOS kernel structures and private data in the upper memory block
|
|
area.
|
|
|
|
--------------------------------------------------------------
|
|
|
|
EMS, VCPI, and virtual 8086 mode incompatibility.
|
|
|
|
DOSBox-X's VCPI emulation is incompatible with Windows 3.1.
|
|
Windows 3.1 will complain (from the DOSMGR driver) that it
|
|
cannot run with the protected mode manager.
|
|
|
|
You must disable the option that says to start DOSBox-X with
|
|
expanded memory and virtual 8086 mode active to run Windows 3.1.
|
|
|