As far as I can tell, it was not inserted in code initializing a DES chip. It was shipped with the ROM monitor, and the DES chip, which would have been initialized by software (not boot ROM), was not even shipped.<p>The article is a little confusing but it looks like an email reply to multiple questions, the first one &quot;Why this message&quot; and the second one &quot;Why the empty chip slot&quot;. (And the third one about a Sun-2 emulator, which also comes out of nowhere.)