[comp.os.msdos.programmer] exe file headers

Rob.Wedlock@samba.acs.unc.edu (Rob Wedlock) (12/30/90)

Hi!
  Many many thanks to Chobuka Joe for answering my question about
  stdin handle. Turns out my handbook says it's 1 when its actually
  0. Clears everything up!

  Now, I have noticed something strange happening with exe files!
  In the same handbook (ugh!) it shows me all the meanings of the
  bytes in the exe file headers. At offset 4 it says is a word
  which is the size of the file div 512, at offset 2, the file size
  mod 512. Well, if i do the mathematical gymnastics on the numbers,
   so far I have yet to match  the result with the value in the directory!
  Most of the time it's larger. On telemate, its ALOT smaller, and
  using debug, I see that dos doesnt even load the whole tm.exe file!
  If I manually edit the header and change the value too big, dos
  says the exe file is in a bad format!! 

  I'm curious.  Does anyone know how this works? Replies thru emial
  would be very much appreciated!!
]
Thanks!!
rob.wedlock@samba.acs.unc.edu