Bc2000 (for the BCF2000 & BCR2000)

Hi guys,

While working on implementation file for SY77 I encountered a problem
I cannot solve: sending a specific range with sign bit. Long story
short:
 - values 0 ... 7 correspond to range 0 ... 7
 - value 8 is ignored
 - values 9 ... 15 correspond to range -7 ... -1

Of course the configuration with a jump from 7 to -1 is still usable,
but I was thinking if it's possible to overcome it somehow. Any hints
would be appreciated.

Thanks,

Bruno