Ersatz-11 uses a device-independent interface to attach any supported terminal device type as the physical side of any supported PDP-11 terminal device type. Each line is created using a one-line ASSIGN command in the E11.INI initialization text file. SET commands may be used to modify the port type, CSR/vector addresses, and interrupt priority, but in many cases this is not necessary thanks to E11's sophisticated rules for choosing default values for these parameters, which include automatic computation of "floating" CSR and vector addresses. Terminal port emulation is done on a line-by-line basis, so it is possible to mix and match any combination of physical terminal lines within the same emulated multiplexor.

The DOS/Windows versions of E11 include emulation of the VT11 vector graphics processor, monitor, and light pen. This is included mainly for hobby users, to run the famous lunar lander game.

Physical PC terminal devices: (E11 for DOS)

• Emulated VT100 on SVGA -- can flip between up to 12 virtual screens, VESA and Trident 132-column modes are supported; keyboard is fully customizable using scripts for each key, default keyscripts emulate VT100 keyboard including keypad
• COM ports (FIFOs supported if available, including 16C650A etc.)
• LPT ports (including PCI LPT boards)
• Comtrol RocketPort multi-serial boards (full version only)
• Chase Research (now Perle) PCI-FAST multi-serial boards (full version only)
• Boca (now Zoom, but Inprimis owns older products) multi-serial boards (full version only)
• Digi AccelePort Xe (and older PC/Xe) multi-serial boards (full version only)
• (see comparison of multi-serial boards)
• Sound Blaster MIDI port

Physical PC terminal devices: (E11 for Windows)

• Emulated VT100 in a window -- same as DOS version, but better-looking
• Any serial or printer device supported by Windows

Physical PC terminal devices: (E11 for Linux)

• Emulated VT100 on SVGA -- same as DOS/Windows version, except for the 132-column mode (not supported by /dev/vcsa* device)
• Any serial device supported by Linux
• Built-in Telnet server

Any two or more of the above port types may be combined and connected to the same emulated PDP-11 port, with output copied to all, and all input merged

Emulated PDP-11 terminal devices:

dev name	controller types	description	E11 versions
LP:	LP11, LPV11	line printer ports	all
TT:	DL11, DLV11	serial line units	all
VR:	VT30	raster graphics display	all DOS
VT:	VT11	vector graphics scope	all DOS
YH:	DH11	early DMA mux	full
YJ:	DJ11	early programmed I/O mux	full
YM:	DM11BB	modem control option for DH11	full
YV:	DHU11, DHQ11, DHV11, etc.	microcomputer-based DMA mux	full
YZ:	DZ11, DZQ11, DZV11	programmed I/O mux	all (as of V3.1)