User-added Postscript fonts

[Mark Fardal <fardal(at)weka.astro.umass.edu>]

Hi,

I finally figured out how to add the AMS math Postscript fonts to IDL.
They have some symbols that are not available in the standard set
of Postscript fonts.  If I could make them available, I'd never need
vector fonts in PS files again.

Unfortunately, it doesn't seem possible to use more than one such
font at a time.  I thought you would be able to add several by
using font indices, but apparently not:

IDL> help,/device
...
        (!17) AvantGarde-Book           (!18) NewCenturySchlbk-Roman   
        (!19) NewCenturySchlbk-Bold     (!20) <Undefined-User-Font>    
IDL> DEVICE, set_font = 'CMBSY7', font_index=19
IDL> help,/device
...
        (!17) AvantGarde-Book           (!18) NewCenturySchlbk-Roman   
        (!19) CMBSY7                    (!20) CMBSY7                   
IDL> DEVICE, set_font = 'MSAM10', font_index=17
IDL> help,/device                              
...
        (!17) MSAM10                    (!18) NewCenturySchlbk-Roman   
        (!19) MSAM10                    (!20) MSAM10                   

So, if you try something like

set_plot, 'ps' 
!p.font=0
device, /palatino, /bold, font_index=6
device, set_font = 'MSAM10', font_index=17
device, set_font = 'CMBSY7', font_index=19
plot, indgen(10), title = '!20what font am i this time?!6'
xyouts, .3, .5, /normal, '!6M!d!19'+string(12b)+'!n!17' $
     +string(46b)+'!6 2 !m'+string(180b)+ '!x 10!u33!n g', size=1.7
device,/close

you can get one special symbol or the other correct, depending on the
ordering of the "device, set_font" statements, but not both.  A
further drawback of this is that it is harder to modify TeXtoIdl to
produce the correct symbols.

I don't see anything in the documentation about this behavior.  
Is this a quirk of my system?  which is namely
  x86 linux unix 5.2.1, Debian linux

thanks,
Mark Fardal
UMass