# cat /dev/acd0
cat: /dev/acd0: Invalid argument
# ls /dev/acd*
/dev/acd0       /dev/acd0t01    /dev/acd0t02    /dev/acd0t03    /dev/acd1
<SWAP AUDIO CD FOR FREEBSD JP-SNAP CD>
# cat /dev/acd0


Fatal trap 12: page fault while in kernel mode
fault virtual address	= 0x1c
fault code		= supervisor read, page not present
instruction pointer	= 0x8:0xc0505f98
stack pointer	        = 0x10:0xd886ec88
frame pointer	        = 0x10:0xd886ec9c
code segment		= base 0x0, limit 0xfffff, type 0x1b
			= DPL 0, pres 1, def32 1, gran 1
processor eflags	= interrupt enabled, resume, IOPL = 0
current process		= 2 (g_event)
kernel: type 12 trap, code=0
Stopped at      devstat_remove_entry+0x98:      cmpl    %ebx,0x1c(%edx)
db> tr
devstat_remove_entry(c44bd3c0,0,0,c4586e80,d886ecd0) at devstat_remove_entry+0x98
g_destroy_provider(c4586e80,c0653a4c,c4586ed4,c4586e80,4) at g_destroy_provider+0x48
g_orphan_register(c4586e80,0,0,0,66666667) at g_orphan_register+0x5d
one_event(d886ed18,c04b5445,c069ba54,0,4c) at one_event+0xfc
g_run_events(c069ba54,0,4c,c064dd2d,a) at g_run_events+0x8
g_event_procbody(0,d886ed48,0,40,0) at g_event_procbody+0x25
fork_exit(c04b5420,0,d886ed48) at fork_exit+0x7f
fork_trampoline() at fork_trampoline+0x8
--- trap 0x1, eip = 0, esp = 0xd886ed7c, ebp = 0 ---