ach of
the addressing modes and the immediate mode.
</p>

<div class="org-src-container">

<pre class="src src-c" id="mode_offsets">/* Offsets of the space modes in the mode nibble. */
static const uint8_t
    RB_ADDRA_LSB = 0,
    RB_ADDRB_LSB = 1,
    RB_ADDRC_LSB = 2,
    RB_IMMED_LSB = 3;
</pre>
</div>

<p>
From here it&rsquo;s reasonably trivial to fill the <code>unpacked_s</code> struct. <code>instr</code> needs
to be shifted and masked a couple of times to fetch the opcode and registers,
but nothing 