INKEY$ doesn't work with fixed length strings

[DSMan195276]

I think your program is just running too fast for the character to appear on the screen. Keep in mind that a fixed length string is never empty, so when you do the `PRINT` it will always put out two characters when printing the string. NUL bytes (CHR$(0)) will fill the fixed-length string when nothing was returned by INKEY$ and when printed those appear like a space, so they will overwrite whatever was previously on the screen.