==61055== Invalid write of size 4
==61055==    at 0x6332D2F: memset (in /usr/lib/valgrind/vgpreload_memcheck-amd64-linux.so)
==61055==    by 0x71883E: c64_software_list_cartridge_load(device_image_interface&) (c64.c:1117)
==61055==    by 0x718A13: device_load_c64_cart(device_image_interface&) (c64.c:1175)
==61055==    by 0x1C599B0: cartslot_image_device::call_load() (cartslot.c:226)
==61055==    by 0x19E7A15: device_image_interface::finish_load() (diimage.c:1088)
==61055==    by 0x1A232AF: image_postdevice_init(running_machine&) (image.c:268)
==61055==    by 0x1A13563: driver_device::device_start() (driver.c:269)
==61055==    by 0x19DFCD8: device_t::start() (device.c:449)
==61055==    by 0x1AA6133: running_machine::start_all_devices() (machine.c:960)
==61055==    by 0x1AA4360: running_machine::start() (machine.c:311)
==61055==    by 0x1AA48E7: running_machine::run(bool) (machine.c:372)
==61055==    by 0x1AA22B3: mame_execute(emu_options&, osd_interface&) (mame.c:190)
==61055==    by 0x19C94F4: cli_frontend::execute(int, char**) (clifront.c:255)
==61055==    by 0x13154D8: main (sdlmain.c:371)
==61055==  Address 0x0 is not stack'd, malloc'd or (recently) free'd