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Adding a USB floppy emulator to an old synthesizer using Flashfloppy firmware

Here's a short video on how to get that GoTek USB floppy emulator working on your Yamaha SY99, explained in roughly 5 minutes. If you don't have the time, here's what you need:

  1. A GoTek USB floppy emulator, e.g. https://encr.pw/4i4S2
  2. A USB serial adapter, e.g. https://acesse.dev/Vq4fP
  3. or a USB-A to USB-A cable in case you found an Artery chip inside your floppy drive emulator: https://l1nq.com/6XGYw
  4. some wires, maybe https://encr.pw/URqqz
  5. a 34pin to 26 pin adapter cable, if you replacing an original drive: https://l1nq.com/dArgy
  6. Flasher software for ARM chips: https://www.st.com/en/development-tools/flasher-stm32.html
  7. or for Artery chips: https://www.arterytek.com/en/product/AT32F435.jsp ("In-Circuit-Programming tool supporting AT32 MCU")
  8. Flashfloppy: https://github.com/keirf/flashfloppy/wiki/Downloads

So you bought one of those $20 USB floppy emulators to install in a SY99. Those won't work out of the box. What you need to do is to open them up by removing the 3 screws on top of them.
Now, take a look at the inscription on the tiny processor found on the main board. There are two chips you can find here: ARM STM32F105 or Artery AT32F415.

Depending on what you find, you may need a USB flash adapter for the STM or a special USB cable with type A ends on both sides for the AT32.

In my case, I found an STM32F105 chip inside. As I had no suitable USB cable, I used this USB serial port adapter on a breadboard. I also needed some connector cables that plug into the breadboard.


Take a look at your USB floppy drive. There should be a set of pins near the power plug, a row of 5 pins and another row of four pins.
On most boards, there are holes instead of pins. In that case, you can either solder the pins on yourself or just plug the wires into the holes and attach them with needles or anything that will secure them in place.

If you have pins, you can now place a jumper on the outermost of the 5 pins. This will put the drive into flash mode. If you don't have the pins, you can use a short wire.

Then take a look at the schematics of the serial adapter. We're going to use 4 pins: TX, RX, VCC and GND, which are abbreviations for transfer, receive, voltage and ground.

The TX of the serial adapter must be connected to the RX pin of the usb floppy drive, and the TX of the floppy must be connected to the RX of the serial adapter.
Then, connect the voltage pin and ground pin of the adapter to the power plug of the usb floppy drive.

Now, connect the serial adapter to a USB port on your computer. Download the flash image installer by st electronics and install it. Then, download a software called flashfloppy. Unzip the archive.

Launch the flash image installer and select your COM device. I found using a lower baud rate to be more successful. Click next. 

If your device isn't found at first, don't worry. Perform a reset by briefly short circuiting the two innermost pins on the usb floppy drive, then try again. Eventually, your floppy drive will be found and connected.

If necessary, click the remove protection button.

On the next screen, just press next.

Then select download to device and select the hex file inside the flash floppy folder you unzipped previously. Change the filetype filter if needed. Select the hex file that is named after the chip on your floppy drive board, in this case STM32F105.

Then press next and wait for the download process to finish.

Next, set jumpers as seen on screen right now to make the drive work with your SY99. The order is two empty colums of pins, jumper, one empty column, jumper.

Now, let's prepare a USB stick. Make sure it's formatted in FAT32, which by default all USB sticks are. Download a software called winimage. Install and launch it, then create a new image file. Select 720kb. Select the Inject file option and then select the files you want to transfer to your SY99. Once finished, select write and place that image file in the root folder of you USB stick.

Now, close the lid of the floppy drive and fix it with the screws to install it in your SY99. In case you were replacing the original floppy drive, you will need a 34 pin to 26 pin adapter cable like this.

Once everything is in place, you can insert the USB stick into the new USB port and load the files you copied to the stick previously.

If for some reason you encounter problems, you can reset the floppy drive by removing the USB stick and pushing the two select buttons simultaneously for 3 seconds.