emulator: rpix86
type: standalone
core_classification: other
source: "http://rpix86.patrickaalto.com/rdown.html"
upstream: ~
profiled_date: "2026-10-20"
core_version: "0.19"
display_name: "DOS (rpix86)"
cores: [rpix86]
systems: [dos]
verification: existence

notes: |
  Patrick Aalto's x86 DOS emulator for the Raspberry Pi, freeware and closed
  source. Profiled from the binary RetroPie installs,
  files.retropie.org.uk/archives/rpix86.tar.gz (sha256 8591b715f7c5...ad328d),
  an ARM EABI5 executable whose banner reads "rpix86 (Raspberry Pi x86
  emulator) v 0.19" with "BIOS date: Jun 28 2015". The BIOS, VGA and sound
  emulation are inside the binary. Its strings name no ROM, font or patch
  file, only the shell below, /boot/config.txt (overscan defaults), the
  input and serial devices, and the log and screenshot files it writes.

  C:\ is the directory given with -d, the working directory by default
  (usage text). The emulator looks for its shell as C:\4DOS.COM or
  C:\4DOS\4DOS.COM. When neither exists it stops with "Unable to find
  4DOS.COM command interpreter (shell)" and offers to fetch it with
  "wget http://rpix86.patrickaalto.com/4DOS.COM". RetroPie runs the binary
  from its install directory and unpacks
  files.retropie.org.uk/archives/4dos.zip (sha256 801441f3f65e...5b636a,
  4DOS 7.50 from JP Software) there (scriptmodules/emulators/rpix86.sh).

files:
  - name: "4DOS.COM"
    path: "4DOS.COM"
    system: dos
    description: "4DOS 7.50 command interpreter, the emulated DOS shell"
    installed_on: [retropie]
    required: true
    size: 257520
    sha1: "a44f65d6318582501d22e27831eb2b1f0df58f79"
    md5: "fc3a0078a13d98e611a62c1d6724f8c5"
    crc32: "8300d4cb"
    source_ref: "rpix86 0.19 binary, strings C:\\4DOS.COM and C:\\4DOS\\4DOS.COM"
    note: "Same bytes at rpix86.patrickaalto.com/4DOS.COM, the URL the binary downloads from, and in RetroPie's 4dos.zip. Read from the emulated C: root, not a BIOS directory. The author's rpix86.zip and rpix86.tar.gz hold the binary alone, and RetroPie unpacks 4dos.zip into the install directory."