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.. |version| replace:: 0.2.0
.. |date| date::
=======
marsond
=======
----------------------------------------------------------------
Fix Enter key timing on Marson/USBLink/MT606-1 PS/2-USB adaptors
----------------------------------------------------------------
:Manual section: 8
:Manual group: Urchlay's Stuff
:Date: |date|
:Version: |version|
SYNOPSIS
========
marsond [**-d** *delay-ms**] [**-f**] [**-k** *keyboard-device*] [**-v**] | [**--help**] | [**--version**] | [**-V**]
DESCRIPTION
===========
**marsond** fixes an issue with a particular model of PS/2 => USB
keyboard adaptor. The symptom: in games and emulators, the Enter key
only works sometimes. This is caused by the firmware in the adaptor
sending the keypress and release events only 8 milliseconds apart.
The problem happens with any SDL application (SDL1 or SDL2), as well
as other graphics libraries. It happens regardless of what PS/2
keyboard you have plugged in, what computer you have the adaptor
plugged into, or what OS that computer is running.
The specific hardware that has the Enter key problem for me is USB
vendor ID 04b4, product ID 0101, "Marson Keyboard and Mouse Link
Ver:ps2120L". It has a label on the front that says "USBLink", and on
the back, the model number is "MT606-1". It looks like:
https://slackware.uk/~urchlay/sdl-usblink-hack/marson-front.jpg
https://slackware.uk/~urchlay/sdl-usblink-hack/marson-back.jpg
I'm not sure if any other USB keyboard adaptors are affected. If you
have the problem on some other adaptor, and **marsond** fixes it,
please contact me so I can add the model number to this man page.
**marsond** uses the Linux kernel's **uinput** layer to "grab" the
keyboard, create a new virtual keyboard device, and pass events from
the real keyboard to the virtual one. When it sees the key release
event for the Enter key, it simply pauses for a few milliseconds
before delivering it.
This should work with everything that uses the keyboard. It definitely
does, with SDL 1 and 2 running under X (and SDL 1 on the console,
too). I don't use Wayland, so I haven't tested it there. If you do,
please contact me and let me know if it works for you.
**marsond** must be run as root. At startup, it does these
things as root:
- Grab the physical keyboard.
- Create the virtual keyboard device.
- Lock its pages into physical memory, to avoid being swapped out.
- Set its priority (nice value) to -20 (highest priority), to
avoid slow response on a loaded system.
After doing the above, root access is no longer needed, so it will
drop privileges and run as the *nobody* user by default (but see
**ENVIRONMENT** if you need a different user).
While **marsond** is running, "xinput --list" will show an input
device called "marson virtual keyboard".
OPTIONS
=======
Options can be "bundled": **-vf** is the same as **-v** **-f**.
-d delay-ms
Amount of time in milliseconds to delay the Enter key release events.
Default: 30.
.. delay time for Enter key relase (default 30).
-f
Run in the foreground; do not detach from the terminal or become a
daemon. In this mode, **marsond** can be killed with *^C*.
.. run in foreground, not as a daemon.
-k keyboard-device
Input device for the keyboard adaptor. Default:
/dev/input/by-id/usb-Marson_Marson_Keyboard_and_Mouse_Link_Ver:ps2120L-event-kbd
.. keyboard device (usually under /dev/input/by-id/).
-v
Verbose debugging mode. Prints copious trace information to **stderr**.
Debugging mode is turned off when **marsond** forks itself into the
background as a daemon. If you want to debug the event loop, combine
**-v** and **-f**.
.. verbose debugging.
-h, --help
Shows built-in usage message and exits.
.. this help text.
-V, --version
Shows version number and exits.
.. show version number.
ENVIRONMENT
===========
MARSOND_USER
After initialization, **marsond** will drop privileges by
setting its user ID to this user's. Default: *nobody*
MARSOND_GROUP
Group to run as, after dropping privileges. Default:
the primary group of the user it's running as. Normally
you won't have to set this.
.. EXIT STATUS
.. ===========
.. BUGS
.. ====
.. EXAMPLES
.. ========
COPYRIGHT
=========
WTFPL. Short version: do WTF you want. Full version:
http://www.wtfpl.net/txt/copying/
AUTHORS
=======
B. Watson <urchlay@slackware.uk>
SEE ALSO
========
The homepage: https://slackware.uk/~urchlay/repos/marsond
Another solution to the problem, less complete, but should be portable
to non-Linux OSes: https://slackware.uk/~urchlay/sdl-usblink-hack/
|
