Quick question, in some of the gate diagrams the input or output connections sometimes have a diagonal slash through them (i.e. in the ALU diagram on page 36, the input and output have a diagonal slash, while the single bit instructions don't).
I assumed that this was to indicate that they're mult-bit busses, but then the CPU diagram on page 88 (I'm using the printed book) has a diagonal slash through *everything*, including the 'reset' input. But then.... On page 93 the reset is draw without the slash?
The diagonal slash does indicate a bus. The number beside the slash indicates the width of the bus. I don't know why reset is marked /1 on page 88.
Note that you will sometimes see signals named including their width, particularly when truncated buses are present. Consider the CPU where 'pc' exists in both 16 and 15 bit widths. To avoid ambiguity you might need to use pc/16 for the output of the PC chip and pc/15 for the output of the CPU.