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.