unexplained factor of 256 in conversion to voltage

[ddkohler]

@untzag

There is an unexplained factor in the voltage conversion code that I do not understand. Everything seems to work, but it would be more satisfying if we understood the conversion entirely.

https://gitlab.com/yaq/yaqd-gage/-/blob/v2021.3.0/yaqd_gage/_compuscope.py#L113

[kameyer226]

Without asking Gage directly, I wonder if this is a padding to make a 24-bit entry become 32-bit. By 1-padding it may clarify to programmers that these bits are completely off-limits to being filled with real data