Boot ROM usage enables more flexible boot sequences than hardwired logic could provide. In many cases such interfaces are implemented by hardwired logic. It may also be hardwired but controlled by a switch. In some CPU designs the instruction decoder is implemented as a hardwired, unchangeable circuit. Even the controller (a single Famicom controller) is hardwired directly into the Wide Boy. The mode is usually hardwired into the circuit and therefore cannot be changed by software. These are the original models using core memory and a hardwired CPU. Some designs use a combination of hardwired design and microcode for the control unit. Some scholars have suggested that religion is genetically "hardwired" into the human condition. Initially, CPU instruction sets were hardwired. The 1890 Tabulator was hardwired to operate on 1890 Census cards. These speed limits are hardwired onto most rental vessels. Register $0 is hardwired to zero and writes to it are discarded. They eventually made the Amiga demoscene production "Hardwired". It started with an original screenplay written in 1995 by Jeff Vintar, entitled "Hardwired".