@PCB.Wiz - I did not have any luck accessing the factory bootloader.
Hmm...
I also did find this, on a ChipMAX Programmer menu (they do not list N78E058
D)
Manufacturer:WINBOND, Device name:W78E058B
Package Info.:DIP40, Organization:9000h x 8 bit, Adapter name:None, Manufacturer ID.:00DA, Device ID.:0063, Algorithm:Single, Vcc pin(s):40, Gnd pin(s):20, Vpp pin:None, Vccp:5.0V, Vpp:None, Tpwp:50Us, Topwp:None
Manufacturer:NUVOTON, Device name:W78E052D
Package Info.:DIP40, Organization:4000h x 8 bit, Adapter name:None, Manufacturer ID.:00DA, Device ID.:0040, Algorithm:Single, Vcc pin(s):40, Gnd pin(s):20, Vpp pin:None, Vccp:5.0V, Vpp:None, Tpwp:50Us, Topwp:None
Manufacturer:NUVOTON, Device name:W78E516DPG
Package Info.:PLCC44, Organization:11000h x 8 bit, Adapter name:PA44-48U, Manufacturer ID.:00DA, Device ID.:0070, Algorithm:Single, Vcc pin(s):44, Gnd pin(s):22, Vpp pin:None, Vccp:5.0V, Vpp:None, Tpwp:150Us, Topwp:None
The W78E516D/W78E058D Data Sheet is shared, so the W78E516
D timing, I would expect to apply for the W78E058
DGoogle also finds this :
http://www.lapsun.com/sp300u-usb-programmer-for-51avratmelmicrochipsststc-9325293949-chips_p1017.html