N-key rollover

This is a feature that certain keyboards have that let the keyboards register each key regardless of other keys being pressed. It is required for Plover. Read the Wikipedia.org(external link) article about Rollover.

How do I know if my keyboard has N-Key Rollover (NKRO)?

A simple test is to open up a text editor and--while holding down both shift keys--type each letter on your keyboard. If all keys are typed into the text editor, your keyboard probably has nkro.

This site provides a web application that lets you test your keyboard's capabilities for registering multiple key presses. To test, click where it says "click to use", then each key you press lights up green in the picture of a keyboard. Press the middle row keys asdfjkl; and with a normal keyboard only 6 of the 8 keys will light up green, maybe fewer, but if your keyboard has n-key rollover, all 8 will light up green. Then press other multiple-key combinations such as yuhj and see if they all light up green.

What if my keyboard is not capable of nkro?

If you don't have a keyboard that's capable of nkro, but still want to give Plover a try, you can arpeggiate/roll the keyboard chords. More info can be found at the bottom of this post: http://plover.stenoknight.com/2011/02/plover-211-released.html

Known supported keyboards

The Zalman ZM-K600S and Filco Majestouch are confirmed to have at least 16-key rollover over USB. Some of the other keyboards are known not to have usable rollover over USB, though they will probably have sufficient rollover over PS2.

The USB HID drivers in most computers' BIOS (and in the Linux GRUB bootloader) can not read the NKRO HID reports, and only work when the keyboard is in 6KRO mode. NKRO USB keyboards have switches for changing from BIOS compatible 6KRO mode to full NKRO mode. Some have toggle switches on the keyboard housing, and others have hot-key combinations for switching modes. For example, the Noppoo Choc-84 / N-Key-USB powers on in 6KRO mode, and pressing Fn-F12 switches it to NKRO. It will remember that setting as long as it has power to the USB port while the computer is off. If it does not function correctly after switching it, try pressing Caps_Lock twice after changing to NKRO mode. It presents a different HID ID for each mode. Some keyboards change modes with Fn-Del-6 and Fn-Del-n.

Type	Manufacturer	Product Name	Comments	Price
Qwertz	Lioncast	LK10	NKRO over USB	30€
Qwerty	Zalman	ZM-K600S	NKRO over USB	$40
Qwerty	Cooler Master	CM Storm Quickfire TK	NKRO over USB	$85
Qwerty	Corsair	Vengeance K65	NKRO over USB	$90
Qwerty	Noppoo	Choc	NKRO over USB	$95
Qwerty	Logitech	G710+	NKRO over USB	$130
Qwerty	Filco	Majestouch-2	NKRO over USB	$167
Qwerty	Das Keyboard	Model 4	NKRO over USB	$169
Qwerty	SteelSeries	Apex m-800	NKRO over USB	$199
Qwerty	Matias	Ergo Pro	NKRO over USB	$200
Qwerty	Ultimate Gadget Labs	Ultimate Hacking Keyboard	NKRO over USB	$250
Qwerty	Ergodox	Ergodox	NKRO over USB	$295
Qwerty	Keyboardio	Keyboardio	NKRO over USB	$329

Confirmed working steno machines

See also FAQ#What hardware is needed to use Plover?

Plover supports several protocols that are in use by various machines. This means that, in theory, many machines work with Plover. But these machines have been confirmed by users to work with Plover after actually trying it.

Manufacturer	Product Name	Comments
Utopen	Stenoboard	Open source hardware
Scott Urueta	SOFT/HRUF	Open source hardware (see Google Groups thread for updates)
Neutrino Group	Revolution Grand
Neutrino Group	Infinity Ergonomic
Neutrino Group	Infinity Genesis	On linux, /dev/ttyUSB1 is a good bet. Set the protocol to Gemini PR.
Neutrino Group	Gemini2
Stenovations	Lightspeed
Stenograph	Stentura 400 SRT
Stenograph	Protege
Stenograph	Wave
Stenograph	Elan Cybra Student	Instructions
Word technologies	Tréal
Advantage Software	Passport
ProCAT	Flash Writer	Confirmed on Windows and Mac

See also Steno Machine Notes