\c*\c!\c0\c(

[ambrus]

I know it's very simple, but I haven't seen this yet.

print "\u\c*\c5\c3\c4\c`\c!\c.\c/\c4\c(\c%\c2 \u\c0\c%\c2\c,\c`\c(\c!c
+\c+\c%\c2\cJ"

This is, incidentally, no longer warning-free.

There's also a plain TeX equivalent.

\uppercase{\def\ma{^^*}\def\mo{^^4}\def\mu{^^8 }}
\message{\^^-^^!^^`^^5^^3^^4^^`^^!^^.^^/^^4^^(^^%^^2
\^^-^^/^^`^^%\^^-^^5^^`^^(^^!^^#^^+^^%^^2}
\bye