#373 Keystrokes being dropped during rapid typing

[Cygil]

Very rapid typing causes the Linux/X VICE 2.4 to occasionally drop keystrokes. This occurs frequently in word processing applications when a lower case letter occurs too rapidly after the shift key and an upper case letter have been depressed. Additionally, keystrokes are sometimes lost when the emulated machine lags too far behind the keyboard input queue. These might be two separate bugs (and the second might be authentic behaviour.)

I have observed this behaviour in both Vice 2.4 and 2.3.

Platforms observed:
Kubuntu package VICE 2.3 on Kubuntu Linux (kernel 3.2.0-36, KDE version 3.2.0-36, X.Org X Server 1.11.3)
Custom build VICE 2.4 on Kubuntu Linux (kernel 3.2.0-36, KDE version 3.2.0-36, X.Org X Server 1.11.3)

To replicate:
Load word processer (eg SpeedWrite 3.2) in x64 session
Type quickly
Observe keystrokes sometimes get dropped

[gpz]

this is not really a bug... the problem comes from the fact that the keyboard is (and can not) be scanned in real time (ie every 1mhz cycle). even if we could remove the per frame scanning from the emulator itself, the operating system and last not the keyboard itself would still impose a certain limit (something like 10ms for USB HID keyboards, for example). that means if a key is pressed and released within that timespan, the emulator does (and can not) know about it.

so the only workaround is to type slower, it cant be fixed.