Richard,

There was an incompatibility problem between the AFM fonts distributed
via fontinst (they were in general newer) and the fonts distributed
with lw35nfss.zip.  This problem may be solved now but there is still
a checksum problem between ps2pk and the psnfss fonts. Although I know
that not everyone will use ps2pk it shows what kind of subtle problems
there may arise if implementations don't obey the upward compatibility
rule (which is obeyed by LaTeX2e but not when using psnfss).

Psnfss should provide us with the new standard for using PostScript
fonts in LaTeX and also plain TeX. In this respect it should replace
the old handcrafted method of Tomas Rokicki. In fact Sebastian Rathz
promised me that work was being done in this respect (with the date of
18 Januari of this year). Do you know when we can expect this new TeX
standard for PostScript fonts?

--Piet

Ok. Here a `proof' that there is still a checksum problem!
---------------------------------------------------------
Old Rokicki method:

1) afm2tfm Times-Roman.afm -v ptmr.vpl rptmr.tfm

2) vptovf ptmr.vpl ptmr.vf ptmr.tfm

3) ps2pk Times-Roman.pfb ptmr.300pk
   (psfonts.map:ptmr Times-Roman)

4) Checksums match:
   ptmr.vf   && ptmr.tfm   = 1039557284
   rptmr.tfm && ptmr.300pk = 3255410011

New psnfss method:

i)   setenv TEXINPUTS $FONTINST/afm:$FONTINST/inputs:$FONTINST/examples

ii)  tex fontinst.sty
     *\latinfamily{ptm}{}\bye

iii) We have (?) now:
      ptmr7t.vpl -> ptmr7t.tfm + ptmr7t.vf (via vptovf)
      ptmr0.pl   -> ptmr0.tfm	           (via pltotf)

     pltotf ptmr0.pl ptmr0.tfm
     vptovf ptmr7t.vpl ptmr7t.vf ptmr7t.tfm

iv)  ps2pk Times-Roman.pfb ptmr0.300pk
     (psfonts.map: ptmr0 Times-Roman

v)   Checksums differ:
     ptmr7t.vf && ptmr7t.tfm   = 104037337
     ptmr0.tfm && ptmr0.300pk  = 3402066811 && 3255410011

The reason that PS2PK, using the same method as AFM2TFM from DVIPS,
computes a different checksum than PLTOTF (the fontinst method) is
because PLTOTF does not look at the Times-Roman.afm file.  FONTINST
can not implement this AFM2TFM method! I consider writing FONTINST in
plain TeX a software design error! It is like writing ps2pk in
Assembler.

I am trying to write a perl script that computes the checksum via a
small C-program and fills this in the appropriate .pl file before
running PLTOTF. But it is hard to find, other than by trial and error,
what relations there are between encoding, style file and needed
fonts.

--Piet

