Question: I am trying to use the pigpen font <https://ctan.org/tex-archive/fonts/pigpen> by Oliver Corff.

The pigpen.tex file is *really* small and seems equivalent to the following:

```
\font\pp=pigpen

```

but the following won't produce a valid PDF using xetex

```
\font\pp=pigpen

{\pp HELLO WORLD}

\bye

```

> 
> `Sorry, pfa format not supported`
> 
> 
> 

What am I missing?

Answer: 
[![enter image description here](https://i.stack.imgur.com/omIVD.png)](https://i.stack.imgur.com/omIVD.png)

If I run your example in texlive 2022 get

```
xdvipdfmx:fatal: Sorry, pfa format not supported; please convert the font to pfb, e.g., with t1binary.

```

and indeed texlive does only have a `pfa` version rather than the compressed `pfb` form.

So...

```
t1binary /usr/local/texlive/2022/texmf-dist/fonts/type1/public/pigpen/pigpen.pfa  pigpen.pfb

```

Makes a `pigpen.pfb` in the current directory

```
cp  /usr/local/texlive/2022/texmf-dist/fonts/map/dvips/pigpen/pigpen.map .

```

makes a `pigpen.map` which looks like

```
pigpen <<pigpen.pfa

```

edit that so it says

```
pigpen <<pigpen.pfb

```

Then

```
xetex --no-pdf yourfile

```

will make `yourfile.xdv` and `xdvipdfmx` will make the pdf if you supply the modified map

```
xdvipdfmx -f pigpen.map yourfile.xdv 

```

produces a PDF with the output above.
The following worked for me in plain (Xe)TeX:

```
\input pigpen
\mypigpenfont
HELLO WORLD
\bye

```

[![Pigpen sample](https://i.stack.imgur.com/qduKt.png)](https://i.stack.imgur.com/qduKt.png)

It embeds a type 3 (bitmap) font, rather than a vector font.