Everything is slower when SHIFT and ALPHA keys are held.

[AquaEBM]

Describe the bug

Python script execution and scrolling, loading plots in the Grapher app, calculations, even simply opening apps... The whole operating system just drastically slows down when the SHIFT and/or ALPHA keys are pressed. The effect doesn't seem to cumulate when both keys are clicked.

To Reproduce

There are many ways to reproduce this slow motion effect, examples:

• Consider this python script that naively draws a filled circle:

  def disc(x,y,r,c):
  for w in range(-r,r):
  for h in range(-r,r):
    if w*w+h*h<=r*r:
      set_pixel(x+w,y+h,c)
  disc(160,111,110,(0,0,0))

  Copy it onto your calculator and run it, then run it again while holding the SHIFT and/or ALPHA keys, Waaaayyy slower.

  • Try graphing sin(x) in the grapher app, then try graphing it again while holding any of the two keys before selecting "Plot Graph".
  • Try selecting text in a Python script, (using the SHIFT key), if the cursor goes off screen, the view will redraw very slowly, whilist scrolling normally is practically instantaneous.
  • Try opening any app while holding SHIFT or ALPHA, the view will also redraw very slowly.
  • Interestingly, this doesn't seem to happen when ion.keydown is used to detect a keypress to any of these two keys during the execution of a Python script: Consider this script (which involves pressing the ALPHA and VAR keys). No slowdown.

    Environment

  • Epsilon 19.4.0. But i've been experiencing this since Epsilon 18
  • Platform: N0110

[AquaEBM]

Any progress on this issue?

[EmilieNumworks]

This is a consequence of our keyboard matrix design. When you press shift or alpha, we cannot rely anymore on hardware interruptions on the corresponding column pins to detect new key events. This forces us to scan regularly the keyboard slowing down the whole run loop.