What is it?

Overview
Take a STM32F407 board. Wire it into an MSX cartridge slot..
Make a FAT32 partition on a micro SD card and put rom and dsk images on it.
Plug the micro SD into the STM32F4 board.
The STM32F4 board presents a rom image in real time to the MSX/MSX2 computer such that it thinks a rom cartridge is attached.
It also emulates a WD2793 floppy disk controller such that you can load disk images off the SD card. Two floppy drives are supported; A: and B:
It also (optionally) partially emulates a RP5C01 RTC chip (enough of it to make an MSX2 computer boot if you don't have that chip). This is only really of use to me! Comment out the ENABLE_RTC_RAM_BANK_EMULATION line in the Makefile if you don't need this emulation.
The code is still really 'proof of concept'. There is one button that allows you to cycle to the next rom or disk in a directory. Another button takes you to the previous rom or disk. However, I've added a simple boot menu mechanism where an MSX native program (kcmfs) presents a menu of files from the SD card and lets you boot from one of them.
I used an Omega MSX2 computer to test this. I have not tested it on any other MSX or MSX2 computers. As I've discovered with this project there is quite a bit of variation with MSX and MSX2 systems, so it helps to have 'low expectations'. My goal with this project was to do something 'technically interesting' and to 'run a few games' and then move on to some other project.

And yes you have to compile the firmware. It helps me enormously in terms of troubleshooting if you can set things up to compile the firmware from the source. Otherwise it's really hard to help people diagnose issues.

Why did you make it?

What makes it special?

It supports MSX1, MSX2 and MSX2+, including 1ChipMSX clones, but please turn off overclocking before using it, it works well at the default 3.57MHz.
Features:
1. A very convenient OSD screen that can display three lines of file names.
2. Supports scrolling display of long file names.
3. It can also support sub-directory browsing.
4. It has a buzzer that can imitate the sound of a real floppy drive.
5. It has a file position memory function. When you close MSX and open it again, the file cursor will stay at the last position.
6. It fully simulates the functions of WD1793 and supports disk read and write functions.
7. It has a read and write indicator light.
8. It supports ROM emulation of 128kb and below, including ascii8/16, konami4/5.
9. It supports standard 720k disk emulation, with good compatibility. You can download games in File Hunter.
10. It supports Micro-SD with FAT32.