global name 'self' is not defined - noob trying to learn

[mark.seagoe at gmail.com]

It needs to read HW reg and adjust ChipRegister value, or
ShadowRegister and change the HW value (order was reversed).  I will
look at MyHDL again though to see if there is some reason it can print
class subclassed from intbv, or if it even has a class subclassed from
intbv, without casting as a long in the main program.