ROM-only jump test code

When I was first starting out I ended up with a system which had a Z80, clock source and a ROM and nothing more. This meant that I should be able to execute programmes,
but had no way of interacting with the system to even know if it was working. My solution to this was to break out my HP1630G Logic Analyser and watch the data and
address pins, and run a very simple jump programme, as below.

The code works by executing a series of NOPs, and then a jump (which is encoded as a C3, followed by the two-byte destination address - most-significant byte first).
In this manner, the Z80 will begin executing, then jump to $001e, which is another jump instruction, this time back to $0000, at which point we'll go around the loop again,
infinitely.

You then watch your logic analyser, in particular the address lines. You should see it fetching instructions from memory locations incrementally until it strikes the jump
instruction, at which point it'll change its programme counter (and where it'll fetch its next instruction), and then immediate jump back. The code, in memory, looks something
like this:

           00  01  02  03  04  05  06  07  08  09  0a  0b  0c  0d  0e  0f
  $0000    00  00  00  00  c3  1e  00  00  00  00  00  00  00  00  00  00
  $0010    00  00  00  00  00  00  00  00  00  00  00  00  00  00  c3  00
  $0020    00  00  00  00  00  00  00  00  00  00  00  00  00  00  00  00
  

Your stream of bytes from the logic analyser should look something like this, where 'Address' is the value on the address bus, and 'Data' is the value on the data bus,
ignoring the random things in-between processor cycles (like the DRAM refresh and the junk on the bus while the Z80 is executing the instruction). I've also included
the decoded instruction next to it for clarity:

  Address:    Data:    (Instruction)
  $0000       00        NOP
  $0001       00        NOP
  $0002       00        NOP
  $0003       00        NOP
  $0004       C3        
  $0005       1E        
  $0006       00        JMP $001e
  $001e       C3        
  $001f       00        
  $0020       00        JMP $0000
  $0000       00        NOP
  $0001       00        NOP
  $0002       00        NOP
  $0003       00        NOP
  $0004       C3        
  $0005       1E        
  $0006       00        JMP $001e
  $001e       C3        
  $001f       00        
  $0020       00        JMP $0000
  

Wash, rinse and repeat.