MAME doesn't emulate HLCD0569. I'll see what I can do in the coming days. If it's very similar to HLCD0515, it shouldn't be a problem.
Indeed, Mattel Computer Gin also uses the HLCD0569. Ideally the more test cases for a new emulated device the better, but the UCOM4 MCU dump was bad. I've reminded kevtris that it needs to be redumped.