[tex-k] Question about io.mf example

[Karl Berry]

    According to this phrase on page 36, it is an error not in CTAN file,
    but on page 32 in MFbook:

      lines 19-23 complete the program for the letter I (copying it from
      Chapter 4)

      penpos1(stem,15); penpos2(stem,12); penpos3(stem,10);

Yes, I think you are right, page 32's line 20 looks stale, lacking the .9.
(All online versions of io.mf that I can find have the .9, BTW.) Thanks. -k