*\input keyboa.tex[w81,jmc]
(keyboa.tex[w81,jmc] 1 (MACRO.TEX[LET,JMC] 1 (basic.TEX 1 2 3 4)
! Lookup failed on file cmr9.TFM[TEX,SYS].
<to be read again>
\font
p.1,l.2 \font @←cmathx \font a←cmr10 \font b←cmr9 \font
c←cmr8
↑t