GRDB
stands for Get Real Debugger, which is a takeoff on the fact it is a
debugger similar to the one which shipped in MSDOS, which works in the
so-called 'real' mode of the x86 processor family. This mode is
what the processor starts in before loading an operating system;
it is compatible with the 8086 processor with some extensions.
GRDB had a life of over ten years and at one point was enjoyed by people developing the computer BIOS code.
Some of the features in GRDB are as follows:
A variety of optional settings
Support for debugging FPU code
Support for debugging Flat Real applications
Recognizes register names for addressing purposes
Command line history
Supports redirection of stdin to run script files
updated Support for PCI bus I/O (y command)
support for MMX instructions and register dump
an option to allow assembly/disassembly of native 32-bit code
support for a debug-like RF command
e command allows entry of strings
command line editing added
numeric processor register dump is more intuitive now
memory preview with the 'r' command
fixed PCI to do all buses
counted 'p' command
/ command allows immediate execution of instructions
DW and DD commands to change the size of dumped memory
32-bit real mode code segment support
automatically evaluates expressions in commands
fixed support for SPAWN functions to work properly
'pr' command support in 32 bit real mode code segs
allows optional entry of start/length pairs on most commands
arithmetic operations on seg regs work
enter key repeats some common commands : D U T F are supported
command line history was made more intuitive
redirecting the standard input works properly now
DTA of debugee is handled properly now
dual monitor support included
added CLS command
colorized displays
debugger maintains a separate interrupt table for itself
DPMI support
will now open .COM and .EXE files when you don't specify a file extension on the command line
NEW! support for serial ports/ANSI escape sequences
GRDB
has built in support for symbol tables. One way of getting the
symbol tables is by using the MKSYM program to parse a map file from
one of the major assemblers. The VALX linker, which is
distributed as part of the CC386 compiler package, also is able to
generate the kinds of symbol tables GRDB uses.
This program has limited usefulness these days as it is an MSDOS program, although it also runs in the DOS BOX on windows XP.