From: muta...@gmail.com   
      
   Hi Waldek (mainly).   
      
   You made a comment that writing an assembler is   
   not difficult. I'm wondering what IS difficult for a   
   basic OS and tools - not necessarily exactly MSDOS   
   which needs to cope with segmentation, but   
   something that looks like MSDOS, regardless of   
   whether it runs on ARM or S/370.   
      
   Here is what I have for MSDOS for the 8086:   
      
   PDOS/86 (OS): about 30,000 lines   
   PDPCLIB (C library): About 17,000 lines   
   SubC (C compiler): About 5,500 lines   
   as86 (assembler): About 13,000 lines   
   pdar (archiver): About 1000 lines   
   ld86 (linker): About 3000 lines   
   pdmake (make): About 2000 lines   
      
   I am not very good with algorithms, nor do I know   
   much of the theory, so at the moment, only numbers   
   1 and 2 are within my capability.   
      
   Note that I am running up against the 640k limit   
   with PDOS/86. The OS and command processor   
   are taking up 300k or something, and when I   
   try to run pdmake (which opens another command   
   processor before running another program), I run   
   out of memory.   
      
   I refuse to change the fundamental design to try to   
   alleviate the memory problems, and instead wish to   
   run the exact (*) same toolchain in either PM16 or   
   PM32 with the D bit set to indicate 16-bit.   
      
   If I go the PM32 route I am wondering whether I can   
   make fairly small (LOC) changes to PDOS/386 to make   
   it accommodate 16-bit (only) programs - the specific   
   MSDOS tools that have been linked with PDPCLIB - I   
   don't care about other MSDOS programs that don't   
   follow "the rules" (*).   
      
   (*) The rules aren't set in stone yet. PDPCLIB still   
   hardcodes 4-bit shifts which won't work on either   
   a Turbo 186 (8-bit shifts) or the above PM16/32   
   scenario, and it is only when the rules exist, and   
   PDPCLIB follows the rules, that I wish to throw   
   64 MB (to start with) at my MSDOS executables.   
      
   Any comment?   
      
   Note that the LOC are mostly the same for PDOS/386.   
   Only the assembler and linker change for those.   
      
   pdas - 6000 lines   
   pdld - 2000 lines   
      
   Thanks. Paul.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)