Drawing genetic linkage maps?

[Markus Kramer]

Hello out there,

does anybody knows a program (rather, a script) that draws a linkage
map?
A linkage map looks like a line, which represents a chromosome, with
named loci at certain positions.

Input might look like:
Chromosome 1 Qarm 100
  Locus Abc at 8.20
  Locus 8.20 at 8.20 left
 .....etc.....

Output should be postscript.

There was an article about a related service at the Jaxon Lab in
Mammalian Genome (1994).
Are there any source-files around? Any ftp-sites to plunder?

Thanks,

Markus