-----------------------------------------------------
Exception at EIP=0000000141991C81 (+0x41991c81): ACCESS VIOLATION
While attempting to write memory at 0000000000000C10
-----------------------------------------------------
RAX=0000000000000C10 RBX=0000000000000000 RCX=00000001419E8410 RDX=0000000000215D08
RSI=0000000000000000 RDI=0000000000215C38 RBP=0000000000000000 RSP=0000000000215C10
 R8=0000000000215D10  R9=0000000000000002 R10=FEFEFEFEFEFEFEFF R11=8080808080808080
R12=0000000000000000 R13=0000000000000000 R14=0000000000000000 R15=0000000000000000
-----------------------------------------------------
Stack crawl:
  0000000000215C40: 0000000141991C81 (delegate_base<void,floppy_image_device * __ptr64,int,_noparam,_noparam,_noparam>::operator=+0x0041, s:\svn\mame\src\emu\delegate.h:521)
  0000000000215C70: 0000000141991B62 (delegate<void __cdecl(floppy_image_device * __ptr64,int)>::operator=+0x0032)
  0000000000215CA0: 000000014198935B (floppy_image_device::setup_index_pulse_cb+0x003b, s:\svn\mame\src\emu\imagedev\floppy.c:110)
  0000000000215DB0: 00000001419D9C7D (upd765_family_device::device_start+0x016d, s:\svn\mame\src\emu\machine\upd765.c:139)
  00000000002162B0: 00000001418EC6F5 (device_t::start+0x01b5, s:\svn\mame\src\emu\device.c:452)
  0000000000216770: 0000000141952E45 (running_machine::start_all_devices+0x0125, s:\svn\mame\src\emu\machine.c:960)
  0000000000216AD0: 0000000141952478 (running_machine::start+0x0738, s:\svn\mame\src\emu\machine.c:314)
  0000000000217040: 0000000141950C83 (running_machine::run+0x0203, s:\svn\mame\src\emu\machine.c:375)
  000000000021D7C0: 00000001417C4B18 (mame_execute+0x01f8, s:\svn\mame\src\emu\mame.c:190)
  000000000021F6E0: 000000014190324F (cli_frontend::execute+0x0a2f, s:\svn\mame\src\emu\clifront.c:258)
  000000000021FBD0: 0000000141EEDDAB (utf8_main+0x017b, s:\svn\mame\src\osd\windows\winmain.c:493)
  000000000021FC10: 0000000141EE99E0 (wmain+0x00b0, s:\svn\mame\src\osd\windows\main.c:82)
  000000000021FC60: 0000000141E88F0C (__tmainCRTStartup+0x00ec, f:\dd\vctools\crt_bld\self_64_amd64\crt\src\crt0.c:241)
  000000000021FC90: 0000000141E8904E (wmainCRTStartup+0x000e, f:\dd\vctools\crt_bld\self_64_amd64\crt\src\crt0.c:164)
  000000000021FCC0: 0000000076CE652D (BaseThreadInitThunk+0x000d)
  000000000021FD10: 000000007728C521 (RtlUserThreadStart+0x0021)