Some signals, such as SIGQUIT, SIGBUS, and SIGSEGV, produce a core dump. See the signal(5) man page for a complete list.
If you have the source code for the program, you can try compiling it with cc -g, and debugging it yourself using dbx or a similar debugger. The where directive of dbx provides a stack trace.
On mixed networks, it can be difficult to discern which machine architecture produced a particular core dump, since adb(1) on one type of system generally cannot read a core(4) file from another type of system and can produce an unrecognized file message. Run adb(1) on various machine architectures until you find the right one.