
                           -----------------------
                           Manual for N_SYSCOM 1.1
                           -----------------------

It  is  now possible to see the Gemdos,  Bios,  Xbios and GEM  (AES  and  VDI)
actions your computer is doing on screen.  N_SYSCOM.ACC can only be run as  an
accessory;  settings  can  be changed (not saved however) by clicking  on  the
"System  Command"  menu.  You can choose between showing or  not  showing  the
system  commands.  Clicking on "Yes" leads to the question about the  position
you want the information showed.  "Top" means at the top of the screen, "Menu"
means just under the menu bar and "Bottom" means at the bottom of the  screen.
The momentary value will be the default button.  Defaults at startup are  "No"
and "Bottom".

Information  will be displayed with the system 8x8 font;  this information  is
written to the screen directly,  which is the reason N_SYSCOM only works  with
the highest,  monochrome resolu-tion. Writing to the screen is done with a VBL
routine,  which  writes  the information each time the screen  has  renewed  3
times, so about 72/3 times pro second.

The VBL routine is installed in the first entry in the VBL queue with the XBRA
id "NSC1". The vector allready installed there will be executed after this VBL
routine is ready.

N_SYSCOM installs its own Gemdos,  Bios,  Xbios and Gem vector.  This is  done
with the same XBRA id "NSC1".  The opcode send to one of those system  vectors
is translated in a 'normal' readable code and printed on screen. The opcode is
then send to the original system vector, so no commands are lost ...

Showing  the information on the screen takes time.  Some measures  with  Quick
Index  1.6  show  that  your Atari is working at about  95%  of  the  original
velocity when N_SYSCOM is installed;  there is practically  no  loss  when  no
information  is shown ...

N_SYSCOM works with all TOS versions and in High resolution (640*400) only ...

There  are no bugs known about this program except the ones  described  above,
which are no bugs actually.  This program is strictly Public Domain, so it may
not  be  sold  in  any way.  N_SYSCOM.TXT  should  always  be  accompanied  by
N_SYSCOM.ACC and the other way around.  Use it at your own risk (though,  what
can happen?).

N_SYSCOM is written in assembler. The actual code is only 1000 bytes: the rest
is data (all the 'readable' commands have to come from somewhere!). The source
can be obtained for a small fee.  Write to the author for further information.

Noud van Kruysbergen
N.I.C.I.
P.O. Box 9104
6500 HE Nijmegen
email:kruysbergen@hnykun53.bitnet

