Dear Dr. Myers,

 As far as the creation of a new format on the ATARI is concerned, the
main thing is getting the path definitions right so that initex can
find all the sources it needs. This can be done rather easily with ATARI,
since it works with a mouse-driven shell. This shell works with several
paths (which can be found when clicking 'PARAMETERS -- ENVIRONMENT'), and
one of these paths indicates where TeX should look for its INPUT-files. This
path directive should then be extended with

 1. the directory where the texsis-files can be found
      (in my case E:\texsis.tex\*)
 2. the directory where the format-files can be found
      (F:\tex\initex\*)
 3. the directory where the styles-files can be found
      (F:\tex\styles\*)

Furthermore the path directive indicating the position of the format files
(in my case F:\tex\formats\*) and the one indicating the position of the
TFM files (F:\tex\tfm_ori\*) should be specified.

 The ATARI initex works with an input file, that tells the program what to
do. The only thing I did was modifying an existing file (in this case
PLAING.INI) and renaming it into TEXSIS.INI. I scratched all the entries
that in my view had to do only with the german language (PLAING stands
for German PLAIN, the use of ATARI-computers is widespread in Germany)
and I changed the call to the german hyphenation file (ghyphen.tex) to a
call to the english one (ehyphen.tex). After this I added a call to the
texsis.tex source and changed the format-name from plaing to texsis.
Then I ran initex and.. it worked! Running INITEX, by the way, comprises
the following on an ATARI: Click on the 'ARBEITEN -- FORMATS ERZEUGEN' entry
(sorry, but I do have a german language-version of the shell, I don't know
whether there is an english version too, but I think so) and then pick the
desired *.INI-file, in our case TEXSIS.INI. 
 For your information I will append the TEXSIS.INI file that I used 
to this mail message. 
 I hope that the above explanation will be of use to you. I must admit that
the information in yout TeXsis manual helped me a lot when interpreting and
modifying the TeXsis.INI-file. This file really is nothing else than an
extended command line. If you have any questions, please let me know and
I'll try to answer them.

Best regards,

Jeroen Rommers
rommers@zeus.rijnh.nl