I dont understand something with the values read from vertical speed offset $02C8
According to FSUIPC documentation for this offset:
Vertical speed, signed, as 256 * metres/sec. For the more usual ft/min you need to apply the conversion *60*3.28084/256
But I noticed that when aircraft start climb and vertical speed gauge needle is moving up, the values from $02C8 are circulating between positive and negative values and the changes are not linear (Even with the conversion as advised above!!)
This is also visible as my servo is jumping from side to side, instead of linear steady move.