86Box Test Environment Setup
============================
This directory contains configuration files for testing the DOS
accelerated video driver demo under 86Box, an x86 hardware emulator.
The 86box.cfg is configured for:
- Intel Pentium 75 MHz (Award 430FX chipset)
- 16 MB RAM
- S3 Trio64 with 2 MB VRAM
- Sound Blaster 16
- IDE hard disk (504 MB image)
- 3.5" 1.44 MB floppy drive
- IDE CD-ROM
Step 1: Install 86Box
---------------------
Download 86Box from https://86box.net/ and extract it to a
directory of your choice. You also need the ROM set -- place
the roms/ folder alongside the 86Box executable.
Step 2: Create a Hard Disk Image
--------------------------------
Use 86Box's built-in disk creation or an external tool:
- In 86Box: Settings > Hard Disks > New
- Create a 504 MB image named "dos622.img"
- Or use: dd if=/dev/zero of=dos622.img bs=1M count=504
The 86box.cfg expects the image at:
dos622.img (in the same directory as 86box.cfg)
Step 3: Install DOS 6.22
-------------------------
1. Copy 86box.cfg to your 86Box working directory (or point
86Box at this directory with the --vmpath flag).
2. Obtain MS-DOS 6.22 floppy images (disk1.img, disk2.img, disk3.img).
3. Start 86Box. Insert disk1.img in the floppy drive:
Settings > Floppy & CD-ROM > Floppy 1 > select disk1.img
4. Boot from floppy (the machine should boot from A: by default).
5. Follow the DOS setup process:
- FDISK: create a primary partition using all space, set active
- Reboot from floppy after FDISK
- FORMAT C: /S
- Run SETUP from the DOS disks
6. Swap floppy images when prompted for disk 2 and disk 3.
7. After setup completes, remove the floppy image and reboot
to verify DOS boots from the hard drive.
Step 4: Install CWSDPMI
-----------------------
The demo is a DJGPP (32-bit protected mode) executable and needs
a DPMI host. Download CWSDPMI from:
http://sandmann.dotster.com/cwsdpmi/
Copy CWSDPMI.EXE to C:\ on the disk image. DJGPP executables
will load it automatically when no other DPMI host is present.
Alternatively, you can use CWSDPR0.EXE for ring-0 operation,
which provides direct hardware access without virtualization
overhead.
Step 5: Copy the Demo
----------------------
Mount the disk image and copy these files to C:\:
demo.exe - the compiled demo executable
cwsdpmi.exe - DPMI host (see Step 4)
You can mount the image on Linux with:
sudo mount -o loop,offset=32256 dos622.img /mnt
Or use mtools:
mcopy -i dos622.img@@32256 demo.exe ::
mcopy -i dos622.img@@32256 cwsdpmi.exe ::
Also copy rundemo.bat for convenience:
mcopy -i dos622.img@@32256 rundemo.bat ::
Step 6: Run the Demo
--------------------
Boot the machine in 86Box and at the C:\> prompt:
C:\>RUNDEMO
Or run directly:
C:\>DEMO 640 480 16
Other supported modes (depending on VRAM):
C:\>DEMO 800 600 16
C:\>DEMO 640 480 32
C:\>DEMO 1024 768 8
Controls:
SPACE - cycle to next demo
B - run benchmark
ESC - exit
Troubleshooting
---------------
- "No supported video hardware found": Verify 86box.cfg has
the S3 Trio64 selected. Check that PCI is enabled.
- Black screen or garbled display: The S3 driver may not support
the requested mode at the configured VRAM size. Try a lower
resolution or color depth.
- "Load error: no DPMI": CWSDPMI.EXE is missing or not in the
PATH. Copy it to the same directory as DEMO.EXE.
- Demo runs but acceleration looks wrong: Some 86Box versions
have incomplete S3 acceleration emulation. Try updating to
the latest 86Box release.
