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There are two hardware problems with QY300.
The first is the FDD: the QY300 is equipped with the much maligned EME-213, which uses a rubber belt as its drive. This problem often applies to hardware synthesizers from the 90s, so the method of converting to IDE 34pin is reasonably popular. Converters also exist, will be relatively easy to obtain. e.g. here
The second is LCD display: SANYO DG06243 display module (Datasheet/Pin configuration) in QY300 doesn't have a backlight function. That isn't bright is too bad. If this had been solved, it would have been a one of the real masterpiece of hardware sequencer.
Ok, then, I'm going to replace the display module.
I decided to replace it with BuyDisplay ERM24064SYG-1 display module. (Datasheet/Pin configuration)
notes: Some details of this replace method was greatly contributed by @nimfdd/Omame Project. Thank you from the bottom of my heart.