DEBUG32 help file
                         ---------------------


Address format:
  segment:offset   is a real mode segment plus offset.
  selector|offset  is a protected mode selector plus offset.
  linear+offset    is a protected mode linear address plus offset.
  Segment addresses (":" identifier) refer to a segment address in both
  real and protected mode.  Selector addresses ("|" identifier) must be
  used in protected mode to refer to a selector+offset value.

Assemble <address>
  Assembles instructions to memory.

BP <address> <R|W|RW|I>
  Sets a breakpoint. If no R/W/RW/I is specified, then the breakpoint is
  for execution only. "R" causes a break on reading data. "W" breaks on
  writing data. "RW" breaks on reading or writing. "I" uses the debug
  registers to break on execution (works with ROM).

BC <address|*>
  Clears a breakpoint (<*> for all breakpoints).

BL
  Lists breakpoints. Format is:  n) e address t=n
  "t=n" is total executions.

CLS
  Clears the screen

CPU
  Displays cpu type, operating mode, A20 status, and prefetch length.

Compare <address_1 <address_2> <L length>>>
  Compares data at <address_1> to data at <address_2> for length <L length>.

DA <address>
  Dump data at <address> in Ascii format.

DB <address>
  Dump data at <address> in byte format.

DD <address>
  Dump data at <address> in doubleword (32 bit) format.

DF <address>
  Dump data at <address> in far pointer (16:32) format.

DP <address>
  Dump data at <address> in pointer (16:16) format.

DW <address>
  Dump data at <address> in word (16 bit) format.

Dump <address>
  Dump data at <address> in the current format.

DR
  Display the debug registers.  They may be directly modified with the
  R DRx command.  The BP command provides a more convenient method of
  setting up the debug registers.

Enter <address <byte<,byte>>>
               'character_string'
  Enters data into memory.

Fill <address <end_address <byte<,byte<...>>>>>
              <L length>
  Fills memory with a repeating value.

FLip ON|OFF
  ON (default) causes switching to the application screen on T and P commands.
  OFF does not switch on T and P commands, and thus may confuse the
  application and debugger screens.

Go <=address> <temp_breakpoint <temp_breakpoint2 <...>>>
  Resumes execution. <=address> sets new IP value.
  <temp_breakpoint> sets breakpoints temporary breakpoint(s).

HELP <initial_command_letters>
  HELP or ? commands alone produce the full help text.
  The help output can be limited by specifying the first letter(s) of the
  command(s) to be described.

Hex value1 value2
  Calculates the hexadecimal sum and difference of value1 & value2.

In <address>
  Inputs a byte from port <address> and displays it in hex.

Load <program_name <address>>
  Loads the specified program.
  An address may be specified for non-EXE format files.

Load <address>
  Loads the file identified by a NAME command.
  An address may be specified for non-EXE format files.

Load address drive_number first_sector number_of_sectors
  Loads data on a sector basis from the specified disk.
  drive_number is 0 for A, 1 for B, 2 for C, etc.
  first_sector is the starting sector on the disk (in hex).
  number_of_sectors is the number of 512 byte sectors (in hex).

LOG <filename>
  Copies all command window output to the specified file.
  LOG without a filename closes the logging file.
  Use of the logging facility is limited to non-DOS, non-interrupt areas
  of code.  Use inside DOS or interrupt handlers does not work.

MEMory
  Shows memory control block allocations.

MORE ON|OFF
  ON (default) pauses command output on each screenfull.
  OFF allows scrolling to proceed uninhibited. This is useful when
  the data is simply being logged to a file, rather than being read.
  When the MORE prompt is issued, any key continues for another full window.
  ESC cancels the command, and a digit allows that many more lines output.

Move <address_1> <address_2> <L length>
  Copies data at <address_1> to <address_2> for length <L length>.

Name <program name | parms>
  Sets the program name for a subsequent Load command.
  Sets the command line parameters for an already loaded program.

Out <address> <value>
  Outputs <value> to port <address>.

PRegs
  Displays the privileged registers. These include the GDT, LDT, IDT,
  and TSS pointers, as well as EFLAGS and the control registers.

Ptrace <=address> <count>
  Traces a single inline instruction or procedure.
  <=address> sets resume location.
  <count> specifies the number of instructions to trace.

Quit
  Quits the debugger and returns to DOS.

R <register_name <new_value>>
  R alone displays all of the registers in the current (16/32) mode.
  R <register_name> displays the current value of <register_name> and
    prompts for input of a new value.
  R <register_name> <new_value> sets a register to a new value.

R16/R32 ...
  R16 sets 16 bit register mode.
  R32 sets 32 bit register mode.
  Both commands perform the same as the "R" command, with the additional
  function of setting the 16/32 bit mode.

RC
  Displays the changed registers.

Read <file_name <address>>
  Reads the specified file. An address may be specified, or defaulted to
  the prefix area + 100h. EXE formatting is read as ordinary data (it is not
  intepreted).

REAson
  Displays the reason for entry into the debugger.

Search <address <end_address <byte<,byte<,...>>>>
                <L length>
  Searches for the specified byte or character values.

SELector value
  Displays the linear address active for the specified selector.

SKIPCR
  Disables access to the control and debug registers for operating
  environments that do not allow such access.

Trace <=address> <count>
  Traces a single instruction.
  <=address> overrides the resume address.
  <count> sets the number of instructions to trace.

U16 <address>
  Interprets memory at <address> as USE16 format assembly language.

U32 <address>
  Interprets memory at <address> as USE32 format assembly language.

Unassemble <address>
  Interprets memory at <address> as assembly language.

Viewswap
  Swaps the display to the application screen.  Any key returns.
  See also the FLIP command.

Write address drive_number first_sector number_of_sectors
  Writes data on a sector basis from the specified disk.
  drive_number is 0 for A, 1 for B, 2 for C, etc.
  first_sector is the starting sector on the disk (in hex).
  number_of_sectors is the number of 512 byte sectors (in hex).

XA page_count
  Allocates page_count EMS pages.

XD handle
  Deallocates specified EMS handle.

XM physical_page logical_page handle
  Maps the specified EMS handle/logical page into a physical page.

XS
  Displays the current EMS status.

* comment
  Enters a comment.

    ----------------------------------------------------------------

                        Bare Metal Debugger 2.0

DEBUG32 (The command-line debugger shipped with this book) is the
predecessor of BMD (Bare Metal Debugger). Some features of BMD:

        - full screen symbolic debugging with source code
        - can run as a TSR
        - can isolate itself from the hardware to allow debugging
            TSR's and device drivers. This is done by using built-in
            keyboard and screen I/O routines.
        - remote machine debugging
        - can be placed in extended memory

To receive upgrades for DEBUG32, send your name and address to the
address below. (There is a $10 shipping & handling fee.)

Receive a $50 discount on the purchase of the Bare Metal Debugger with
purchase of this book. Call or write:

     Quantasm Corp.                               (800) 765-8086  sales
     19672 Stevens Creek Blvd., #307-B            (408) 244-6826  tech support
     Cupertino, CA 95014                          (408) 244-7268  FAX
                                                  76347,3661      CompuServe