🚀 go-pugleaf

Desperately Seeking Solution

 Environment: MS-DOS 6.2/V (Japanese MS-DOS)
    Compiler: Watcom C 9.5
DOS Extender: DOS/4GW Pro

We are having a tremendously difficult time trying to interface a flat-
model, 32-bit protected mode application with the MS-Kanji DOS/V device
driver.  The underlying problem arises in the MS-Kanji's roots as a real-
mode driver.  We have to interface to that driver from a protected mode
environment.  Herein lies the problem.

To interface with the driver, you have to call INT 21h, function 4402
(i.e., read data from an IOCTL device).  This returns a segment:offset
memory location of a far procedure that is the actual programming API.
This API entry-point is a real-mode routine, not capable of being run
in protected mode.  I'm trying to use DPMI function 301h to call a real-
mode procedure from within your protected mode program.  This gets me
part of the way there - the API entry point appears to be called, but
the MS-Kanji driver always returns with an abnormal termination status.
My program works fine in real-mode, but dies in protected mode.

In addition, when reading the API entry-point address from the IOCTL
device, the MS-Kanji driver returns a bogus entry-point pointer when 
attempting to read the data through DPMI function 300 (simulate real-mode
interrupt).  When I tell the driver to read 4 bytes of data, it returns
saying it read 768 bytes!  For some obscure reason, the Kanji driver
appears to hate protected mode environments.

Does anybody out there have any experience with using the MS-Kanji driver
from a protected mode programming environment?  These difficulties are
driving me completely crazy, and with deadlines on-the-line, the pressure
is definitely on to get this last part of our Japanese software project
complete.  Anybody out there with any knowledge to assist in this
situation will be greatly appreciated.


Pat Clawson
TeleGrafix Communications