It try Bootmapper that suggest on YMDK website but it wasn’t work then I looking for many alternative and found QMK that work 🎉
It’s only 4 simple step
1. Create key mapping (hex)
Enter https://config.qmk.fm/#/ymdk/sp64/LAYOUT and make sure the keyboard is select at ymdk/sp64
Config your Keymap by drag & drop
click [compile] button when you ready.
Download “Firmware” after finish compiling
2. Download QMK Toolsbox from github
Download and install from QMK website
Run QMK Toolbox (You may need to allow application to open at system preference)
Open firmware file and select “ATmega32A”
You can open qmk firmware code to confirm that “atmega32a” is the collect for your keyboard
3. Connect keyboard to your computer while hold [Left-Ctrl]
Unplug your board and plug it back in while holding [Left-CTRL], the bottom left key. It doesn’t matter if you’ve remapped it elsewhere it’ll always be that key
QTM Toolbox should say something like “BootloadHID device connected: obdve.at ….”
Now you ready to flash you keyboard
Click [Flash] and don’t disconnect it while flashing
Done 🎉