DOSBox-X supports a range of I/O port and network emulation options, allowing DOS software to communicate via serial and parallel ports, print through a virtual dot-matrix printer, play IPX-based multiplayer games over UDP, and access real host networks through an emulated NE2000 Ethernet card. TheDocumentation Index
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[serial] and [parallel] sections configure COM and LPT ports respectively. The [printer] section controls the virtual printer that attaches to a parallel port. IPX networking uses the [ipx] section, while Ethernet emulation is configured in [ne2000] and backed by either the [ethernet, pcap] or [ethernet, slirp] section.
Serial Ports — [serial]
Each of the nine emulated COM ports is configured with its own key. COM1–COM4 are standard DOS serial ports; COM5–COM9 are extended ports. All share the same set of possible device types and parameters.Device type attached to COM1. Parameters follow the type on the same line as
parameter:value pairs. Possible device types:disabled— port not presentdummy— port exists but discards all data (default for COM1/COM2)file— write serial output to a file; parameters:file:<filename>,timeout:<ms>,openwith:<program>,openerror:<program>,multiplier:<x>modem— Hayes-compatible modem emulator; parameter:listenport:<port>nullmodem— virtual null-modem cable over TCP/ENet UDP; parameters:server:<host>,port:<n>,rxdelay:<ms>,txdelay:<ms>,telnet,usedtr,transparent,inhsocket,sock:<0|1>,nonlocal:1serialmouse— serial mouse emulationdirectserial— pass-through to a real host serial port; parameters:realport:<portname>,rxdelay:<ms>log— log serial data to the DOSBox-X log file
serial1=modem listenport:5000 sock:1Device type attached to COM2. Accepts the same values and parameters as
serial1.Device type attached to COM3. Accepts the same values and parameters as
serial1.Device type attached to COM4. Accepts the same values and parameters as
serial1.Device type attached to COM5 (extended port). Accepts the same values and parameters as
serial1. Optionally specify base:<address> and irq:<n>.Device type attached to COM6 (extended port). Accepts the same values and parameters as
serial1.Device type attached to COM7 (extended port). Accepts the same values and parameters as
serial1.Device type attached to COM8 (extended port). Accepts the same values and parameters as
serial1.Device type attached to COM9 (extended port). Accepts the same values and parameters as
serial1.File used to map fake phone numbers to network addresses for the modem emulator. Each line maps a dialed string to a
host:port destination.Parallel Ports — [parallel]
Nine emulated LPT ports are supported. LPT1–LPT3 are standard; LPT4–LPT9 are extended. Ports can optionally be given explicit base addresses and IRQs withbase: and irq: parameters. Settings can also be changed at runtime via the built-in PARALLEL command.
Device type attached to LPT1. Possible types:
disabled— port not presentreallpt— direct passthrough to a real host parallel port; parameters:realbase:<address>(Windows/BSD/Linux),realport:<device>(Linux, e.g./dev/parport0),ecpbase:<address>(optional ECP register)file— write print data to a file or device; parameters:dev:<devname>,append:<file>,timeout:<ms>,cp:<codepage>,addFF,addLF,openps:<program>,openpcl:<program>,openwith:<program>,openerror:<program>printer— attach the virtual dot-matrix printer (configured in[printer])disney— attach Disney Sound Source emulation to this port
parallel1=file file:output1.prn timeout:1000 openpcl:pcl6 openps:gswin32c openwith:notepadDevice type attached to LPT2. Accepts the same values and parameters as
parallel1.Device type attached to LPT3. Accepts the same values and parameters as
parallel1.Device type attached to LPT4 (extended). Accepts the same values as
parallel1.Device type attached to LPT5 (extended). Accepts the same values as
parallel1.Device type attached to LPT6 (extended). Accepts the same values as
parallel1.Device type attached to LPT7 (extended). Accepts the same values as
parallel1.Device type attached to LPT8 (extended). Accepts the same values as
parallel1.Device type attached to LPT9 (extended). Accepts the same values as
parallel1.Enable dongle emulation on the parallel port. Provides a minimal hardware dongle response for software that requires one.
Virtual Printer — [printer]
The virtual printer attaches to whichever parallel port is set toprinter (by default, LPT1). It emulates a dot-matrix printer and can render output to image files or PostScript, or send it to a real Windows printer.
Enable virtual printer emulation. When enabled, the printer device is available on any parallel port set to
printer mode.Output resolution of the virtual printer in dots per inch (DPI). Higher values produce larger output files with finer detail.
Width of the virtual paper in tenths of an inch. The default of
85 corresponds to 8.5 inches (US Letter width).Height of the virtual paper in tenths of an inch. The default of
110 corresponds to 11.0 inches (US Letter height).Output format for completed pages. Possible values:
png— PNG image files (default, recommended)ps— PostScript filebmp— BMP image files (very large; not recommended)printer— send directly to a Windows printer (setdeviceto specify which one)
When enabled, accumulates all printed pages into a single PostScript file or print job until you press Ctrl+F2 to flush and finalize the output.
Windows printer device to use when
printoutput=printer. Specify a printer device number (e.g. 2) or printer name (e.g. Microsoft Print to PDF). Use - to show the Windows Print dialog once per job, or leave empty to always show the dialog.Directory where printer output files (PNG, PS, BMP) are saved. Defaults to the current working directory.
Directory containing TrueType printer fonts used by the virtual printer:
courier.ttf, ocra.ttf, roman.ttf, sansserif.ttf, script.ttf.Program to launch to open the printer output file after it is completed. For example,
openwith=notepad opens the output in Notepad on Windows. Leave blank to not open output files automatically.Program to launch to open the printer output file if an error occurs during printing. Leave blank to take no action on errors.
When enabled, hides the command window that appears when launching programs specified in
openwith or openerror on Windows.Time in milliseconds after which an incomplete page is automatically ejected when no more data arrives. Set to
0 to disable automatic page ejection.Allow printing of Chinese, Japanese, and Korean double-byte characters (DBCS) when a CJK code page is active. With
auto, this is enabled only for TrueType font (TTF) output mode with DBCS support active. Possible values: true, false, 1, 0, auto.IPX Networking — [ipx]
Enable IPX over UDP/IP tunneling. When enabled, DOSBox-X emulates an IPX network stack and tunnels IPX packets over standard UDP. This allows IPX-based DOS multiplayer games to work across the internet or a local network. All players must have this enabled and be able to reach each other’s UDP port.
NE2000 Ethernet — [ne2000]
Enable NE2000 Ethernet card emulation. When enabled, a Realtek/NE2000-compatible network adapter is presented to the DOS guest. Load the appropriate packet driver inside DOSBox-X using the
nicbase address and nicirq interrupt shown below. Either the pcap or slirp backend must be configured.I/O base address of the emulated NE2000 card (in hex). The default is
300 (0x300). Must match the address used when loading the DOS packet driver.IRQ used by the emulated NE2000 card. Note that COM2 also uses IRQ 3 by default; avoid conflicts by reconfiguring one of them. Must match the interrupt specified when loading the DOS packet driver.
MAC address assigned to the emulated network adapter. Set to
random to have DOSBox-X generate a random MAC address at each launch. If multiple DOSBox-X instances share the same network, each must have a unique MAC address. The AC:DE:48 prefix is reserved for private use — change only the last three octets (e.g. AC:DE:48:88:99:AB).Network backend used to implement the NE2000 Ethernet emulation. Possible values:
auto— useslirpif available, otherwise fall back topcapslirp— user-mode networking via libslirp (no root/admin required; NAT-based)pcap— raw packet capture via libpcap (requires root/admin; full network access)nothing/none— disable the backend (NE2000 card is present but not connected)
pcap Backend — [ethernet, pcap]
Thepcap backend provides raw Ethernet-level access by capturing packets from a real host network adapter. Requires administrator/root privileges on most operating systems.
Host network interface to use for pcap packet capture. Set to
list to display available interfaces from the Help → List network interfaces menu or the Status Window. Then specify the interface by number (e.g. 2) or a substring of the adapter name (e.g. VIA).Read timeout in milliseconds for the pcap device. Use
default to let DOSBox-X select an appropriate value, or specify a number of milliseconds.slirp Backend — [ethernet, slirp]
Theslirp backend provides user-mode networking via a built-in TCP/IP stack. No administrator privileges are required, but the guest is placed behind NAT — it can reach the host and internet, but remote hosts cannot directly initiate connections to the guest without port forwarding.
IPv4 network address of the virtual network shared between the guest and the host-side slirp services.
Subnet mask for the virtual slirp IPv4 network.
IP address assigned to the guest (DOSBox-X) on the slirp virtual network. Configure the DOS packet driver or TCP/IP stack with this address.
IP address of the DNS nameserver provided by the host on the slirp virtual network. Configure this as the DNS server in the guest’s TCP/IP stack.
Starting address for DHCP address allocation within the slirp virtual network. The slirp DHCP server assigns addresses from this address upward.