@mon 
 
            by A. Fachat (fachat@galileo.rhein-neckar.de)
----------------------------------------------------------------------
     @mon is covered by the GNU public License, see file COPYING


0) Preface 
   The Programm @mon is a machine language monitor. 
   I have written this programm some years ago and I do not support 
   it any more. I do also not take any warranty for this programm or its
   use in any form.  

1) How to use
   To use the monitor you have to load the programm into memory as
   a machine programm and save it from overwriting by poking something
   to the basic end pointer, except if you put it to $c000.
   You call the monitor by typing "SYS start-address" in the BASIC editor.
   After being called first, the monitor catches the BRK interrupt pointer
   and starts after a break with the register contents in the monitor 
   registers.

   Note that for M, B, D, C, and F a "shifted" command input directly sends 
   the command output to the printer device.

2) Commands
   adr and adr? are  two byte Hex addresses, byte is a Hex value
       M adr1 [adr2]         Hex+ASCII dump from adr1 (to adr2)
       B adr1 [adr2]         Binary dump (Sprite format)
       D adr1 [adr2]         Assembler listing
       R                     Show internal registers

       A adr                 Assembler from adr
       O adr1 adr2 byte      Fill (Occupy) memory from adr1 to adr2 with byte
       C adr1 adr2 adr3      Compare memory from adr1 to adr2 with memory 
                             beginning at adr3
       T adr1 adr2 adr3      Transfer memory from adr1 to adr2 to memory 
                             starting at adr3
       U adr1 adr2 adr3 adr4 adr5 
                             recalculates all two-byte addresses in the
                             area from adr4 to adr5 that point to the
                             memory from adr1 to adr2 to new addresses
                             in memory starting at adr3
       G adr                 jump to adr, set CPU registers with the
                             values of the internal Registers
       I byte1 byte2         Sets output to Disk to device byte1 and
                             output to printer to device byte2
			     defaults to 8 for disk and 4 for printer.
       L "filename" [adr]    Load File "filename" from disk device (see
                             command "I") (to adr)
       S "filename" adr1 adr2
                             Saves memory from adr1 to adr2 to a file,
                             the contents of the memory is preceded by
                             the adr1 (load address)
       #decimal_number       prints the hex, decimal and binary values of
                             the given decimal number
       $hex_number           see "#"
       %binary_number        see "#"
       ? adr1 operator adr2
                             performs arithmetik operation, valid operators
                             are:
                               +   addition
                               -   substraction
                               *   multiplication
                               /   division
       T adr                 trace walk. Available on the C64 only.
			     You can control it with the following
                             keys:
                               F1  don't execute the next command
                               F3  fast execution: don't wait for a keypress
                               F5  slow execution (as F3)
                               F7  one step ahead
                               J   execute subroutine to the next rts
                               run/stop
                                   as the name says...
                             The trace walk is not very reliable, I didn't
                             know about 'bad rasterlines' and so, so you
                             may be trapped in the routine itself. But,
                             BTW, don't care for "SEI", the NMI timer gives
                             the signal. 
       F adr1 adr2 byte [byte2 [...]]
       F adr1 adr2 "TEXT"    search for text or bytes between adr1 and adr2
       FR adr1 adr2          search for relative jumps 
       FA adr1 adr2 xxx      search for a special addressing mode:
                             you give the adressing mode in the same syntax
                             as in the assembler, instead of the real address
                             you may replace some or all of the Hex digits 
                             by an asterix ('*').
                             example:
                             FA A437 A500 $A32*,X
                             .,A43D LDA $A326,X
                             .,A442 LDA $A327,X
                             . 
                                                   
       X                     exit the programm 
                             The BRK vector is being kept.

3) Scrolling editor

   All dumps may be changed by overwriting. The M, B and D dumps have a 
   screen scroll function, i.e. if you move the cursor of the screen to
   the top or the bottom, you get the listing scrolled.

4) Output Redirection

   The Commands M, B, D, C and F can be redirected to the printer
   device (set with the I command) when the command is entered
   shifted.