user manual

4-2
Debugger General Information
4
Description of 187Bug
The 187Bug package is a powerful evaluation and debugging tool
for systems built around the MVME187 RISC-based
microcomputers.
187Bug consists of three parts:
❏ The ÒdebuggerÓ or Ò187BugÒ; a command-driven user-
interactive software debugger, described in Chapter 5
❏ A command-driven diagnostic package for the MVME187
hardware
❏ A user interface which accepts commands from the system
console terminal
Command Facilities
Facilities are available for loading and executing user programs
under complete operator control for system evaluation.
187Bug includes commands for these tasks:
❏ Display and modification of memory
❏ Breakpoint and tracing capabilities
❏ A powerful assembler/disassembler useful for patching
programs
❏ A self-test at powerup feature which verifies the integrity of
the system
Trap #496 Routines
Various 187Bug routines that handle I/O, data conversion, and
string functions are available to user programs through the TRAP
#496 handler. The TRAP #496 handler is accessible through any of
the trap exception commands TB0, TB1, TBND, and TCND, with
trap vector #496.