The RBSC has released the adapter for the floppy emulator Gotek, that can be used in the side slot of Yamaha YIS503, CX5M, CX5MII and similar MSX machines. This device allows to use a diskless MSX with the DSK images of floppy diskettes, written onto a USB flash drive. There can be up to hundreds of images on the flash drive. They are selected with 2 buttons on the Gotek emulator's case. The images may be changed without restarting the MSX.
The production cost of the device (that is a variant of the TDC-600 controller) is around 10-15 Euro. The production cost of the case is 2-3 Euro. The assembled devices will be, of course, more expensive. The device can use 2 BIOSes - the original one and the English one, the selection is done with a jumper. The 3d model of the case will be released together with other files in our repository in the near future.
The device has an option to provide the external connections for a floppy drive. There's a cover with the interface and power plugs that can be installed into the case, preferably with a glue. This will allow using not only the Gotek emulator as an external drive, but also to use 720kb MSX and even 1.44mb PC drives. See the images below.
So, the Gotek emulator is inserted into the 3d-printed case and is connected to the board with a dual-row 34 pin female connector. The power is supplied by the Molex connector with the wires soldered onto the board (to the floppy power connector). Originally it was planned to use a single row 4 pin female connector soldered to the board to provide the power to the emulator, but the connectors never arrived from China. Being well-soldered, those connectors hold the emulator in place very well. The emulator can be even removed from the adapter without any damage. But it's still unclear whether it can be inserted back without opening the case. This has to be checked later.
As was said earlier, the media for the Gotek emulator is a small USB flash drive, for example mine has over 85 different disk images in DSK format. Here's the video of the controller's test with an externally attached device (Gotek emulator). In the video you can see booking to operating system, changing the image from 004 and 003 and running a game from the third image.
https://www.youtube.com/watch?v=tiLWfNpOVr8
And here's the test of the device with the installed Gotek emulator. First, the system is booted, then the file manager (ND made by Igor Bocharov) is started. Then I swap the disk image and run the 8-file Girly Block game directly from the disk image. The game is 128kb + some additional code, so it takes some time to run it.
https://www.youtube.com/watch?v=rxAZpMTwK3s
Here's how the device looks from inside and oustide:
The thin wire is used to fix an error on board, in the released version it won't be needed. Another wire is on the other side of the board.
And that's how the external floppy connection looks like:
Please ask any questions about the device, I will try to answer all of them.