For some reason, one of the computers here crashed at 4:44am, ie., not a
busy time!

I don't understand what happened - is there anything I should worry about?
The kernel is from source updated on 9 May 2000, and it has a serial
console - nothing plugged into the graphics card. AFAICT everything seems to
be working find now, I just found the crash dump.  #1 seems odd..

vga1 at pci0 dev 20 function 0: Silicon Integrated System 5597/5598
  integrated VGA (rev. 0x68)
wsdisplay0 at vga1

Here's what the core dump has to say:

panic: trap
#0  0xc01cfa9e in vga_accessops ()
(gdb) bt
#0  0xc01cfa9e in vga_accessops ()
#1  0x1350000 in ?? ()
#2  0xc0199c8f in cpu_reboot (howto=260, bootstr=0x0)
    at ../../../../arch/i386/i386/machdep.c:1111
#3  0xc012c820 in log (level=-1071842658, fmt=0xc0398800 "\234b\037À")
    at ../../../../kern/subr_prf.c:218
#4  0xc011fb00 in lockmgr (lkp=0xc0398818, flags=65537, interlkp=0xc022a400)
    at ../../../../kern/kern_lock.c:365
#5  0xc0143c3a in vfs_busy (mp=0xc0398800, flags=16, interlkp=0xc022a400)
    at ../../../../kern/vfs_subr.c:249
#6  0xc0146bcd in sys_sync (p=0xc0226ea0, v=0x0, retval=0x0)
    at ../../../../kern/vfs_syscalls.c:563
#7  0xc0145e65 in vfs_shutdown () at ../../../../kern/vfs_subr.c:2292
#8  0xc0199c67 in cpu_reboot (howto=256, bootstr=0x0)
    at ../../../../arch/i386/i386/machdep.c:1098
#9  0xc012c820 in log (level=-1071783749, fmt=0x0)
    at ../../../../kern/subr_prf.c:218
#10 0xc019e6c9 in trap (frame={tf_es = -1072037872, tf_ds = -1070202864, 
      tf_edi = -1070993408, tf_esi = -1074787716, tf_ebp = -1021461180, 
      tf_ebx = 0, tf_edx = 4956160, tf_ecx = 1024, tf_eax = 0, tf_trapno = 6, 
      tf_err = 2, tf_eip = -1072055072, tf_cs = -1057685496, 
      tf_eflags = 66054, tf_esp = -1070719904, tf_ss = -1071432272, 
      tf_vm86_es = 0, tf_vm86_ds = -1021461152, tf_vm86_fs = -1072095876, 
      tf_vm86_gs = 4956160}) at ../../../../arch/i386/i386/trap.c:309
#11 0xc0100c49 in calltrap ()
#12 0xc0191d7c in uvm_pageidlezero () at ../../../../uvm/uvm_page.c:1286
#13 0xc01008f3 in idle ()
#14 0xc0126185 in tsleep (ident=0xc0f5f748, priority=17, 
    wmesg=0xc01d38f5 "biowait", timo=0) at ../../../../kern/kern_synch.c:432
#15 0xc01402cf in biowait (bp=0xc0f5f748) at ../../../../kern/vfs_bio.c:914
#16 0xc013f699 in bread (vp=0xc311fc58, blkno=0, size=1024, cred=0xffffffff,
    bpp=0xc31dbe70) at ../../../../kern/vfs_bio.c:250
#17 0xc01811e8 in ffs_read (v=0xc31dbea4)
    at ../../../../ufs/ufs/ufs_readwrite.c:133
#18 0xc014b61a in vn_read (fp=0xc2f71ab0, offset=0xc2f71acc, uio=0xc31dbef0,
    cred=0xc03b3000, flags=1) at ../../../../sys/vnode_if.h:271
#19 0xc012e3c7 in dofileread (p=0xc31c9304, fd=4, fp=0xc2f71ab0, buf=0x99000, 
    nbyte=8192, offset=0xc2f71acc, flags=1, retval=0xc31dbf80)
    at ../../../../kern/sys_generic.c:145
#20 0xc012e32b in sys_read (p=0xc31c9304, v=0xc31dbf88, retval=0xc31dbf80)
    at ../../../../kern/sys_generic.c:96
#21 0xc019ec11 in syscall (frame={tf_es = 31, tf_ds = -1078001633, 
      tf_edi = -1077946944, tf_esi = 8, tf_ebp = -1077947096, tf_ebx = 603792, 
      tf_edx = 0, tf_ecx = 603792, tf_eax = 3, tf_trapno = 3, tf_err = 2, 
      tf_eip = 538871, tf_cs = 23, tf_eflags = 582, tf_esp = -1077947124, 
      tf_ss = 31, tf_vm86_es = 0, tf_vm86_ds = 0, tf_vm86_fs = 0, 
      tf_vm86_gs = 0}) at ../../../../arch/i386/i386/trap.c:760
#22 0xc0100cf5 in syscall1 ()