Can a joystick damage an MSX?

12 buttons, with driver source code (link)

I am looking for possibilities and offerings ideas for controller solutions, the subject implies someone is looking for possibilities with the current Joystick/ mouse port and do not want to blow up any important circuit in order to brick the machine completely.
The documentation of the MSX DE9 port varies, about pin 6,7.
Pin 8 can be used for output pulse, which is general info in all documentations. The info about pin 6 and 7 varies.
Pin 6 and 7 can be used as input as well as output, 2 bit, if I am correct.
The duration of pulse can be controlled.
If pin 6 and 7 are used to select matrix, pin 8 can be used for vibration/feedback controller (controller vibrates when being hit, for example)
I am not familiar with hardware soluti ons, like which ic to use or creating boards, but can propose ideas,which I think, or am sure, will work.

In the 90's together with some others started a new game, but could only played with cursor and mouse, keyboard for moving the character and mouse for almost 360 pointing of gun and mouse buttons to fire. This could not not be played by 2 joysticks or you had to use 3 or 4 hands.
I will try to locate the draft and upload.
If there was a controller with which could this, it would open more possibilities for games,
Like ikari warriors, alestes, other shooters with 360 rotation of gun , enemies from the back, left right, more difficulty of games.

Forget about previous post. Got the answer .. just using 2x 4.7K resistors does the work.

Just popped into my brain, if pin 8 is not used for vibration/feedback with a NOR (matrix 0, and pin 6&7 , eg. like 4001, or pin 6&7&8, ic 74LS27) 16 buttons can be utilized.
That will be the maximum of buttons possible for a DB9 port, without bricking your holy MSX. Case closed!
Also referring to: http://www.robotsandcomputers.com/computers/manuals/atari2600_fsm.pdf

Caution: pins of Atari and MSX are different