N-key rollover

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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 Sidewinder X4 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.

NKRO over USB HID is reportedly not working on stock Mac-OSX, but there is a driver available on Github to get it working. (Will someone please document this? I do not own a Mac. -- Ed.)

Commercial PS2 to USB adapters may exist that support NKRO, but at least one DIY solution definitely exists. Geekhack has more details about why USB keyboards and adapters are commonly limited to 6KRO.

Type Manufacturer Product Name Comments Price
Qwerty Microsoft Sidewinder X4 NKRO over USB [No Longer Manufactured]
Qwerty (60%) Vortex - KBT Poker 2 NKRO (after firmware upgrade) ~120$
Qwerty Noppoo Choc NKRO over USB $130
Qwerty Noppoo Chok-84 / N-Key-USB $89 to $130, shop around.
Qwerty Razer Tarantula NKRO $100
Qwerty Das Keyboard Model S * NKRO $129 - $135
Qwerty Das Keyboard Model 4 NKRO over USB $129 - $135
Qwerty SteelSeries 7G NKRO $150
Qwerty (tenykeyless) Corsair K65 (CH-9000040-UK tested) NKRO over USB $90
Qwerty Filco Majestouch-2 NKRO over USB $150
Qwerty Keycool Keycool II NKRO over USB $140
Qwerty Cooler Master CM Storm Quickfire TK NKRO over USB $92
Alternative DataHand Systems Inc. DataHand PS/2 version NKRO Find used ~$500-1000
Qwerty Cherry Multiboard V2 G80-8200HPDUS-2 NKRO Find used ~$40
Qwerty Kinesis Maxim PS/2 version (KB200PC) NKRO Find used ~$30-100. Modern USB version is only 6KRO
Qwerty Logitech G710+ NKRO over USB ~$150
Qwerty Various Laptop Keyboard Not NKRO, but can arpeggiate keys

Confirmed working steno machines

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
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 Confirmed working on Windows but not working on Mac OS
Stenograph Elan Cybra Student Confirmed on windows, Mac and linux. Instructions
Word technologies Tréal Confirmed on windows and mac but not on linux
Advantage Software Passport
ProCAT Flash Writer Confirmed on windows and Mac