These days the idea of building a hybrid MSX FPGA + Raspberry Pi 4 (RPI4) is wandering in my head.
I really like that the SX-1 board can be put inside a mini ITX PC case, and morever, there's plenty of room inside to add more things. Something I'd like to do is to do is to add a switch to choose to power up the SX-1 or the RPI4, and to share the micro-SD card between the SX-1 board and the RPI4. The RPI can communicate with the SD card via SPI, and all I'd need is to use one of the pins of the RPI as a control signal to connect the SD card (that by default will be connected to the SX-1), with an analog switch.
But looking at the board's picture in the manual I see that the pins of the SD card are made accesible, as well as the power on control (I don't know if you can power off with the same pin). It's really cool that the designer of the board did that 
I don't want to do anything complicated, just a little board with analog switchess (at least, for the SD card and the USB keyboard) and connectors to power up the SX-1 and the RPI4, an along switch to turn on the SX-1 or the RPI4, and little more. If I can connect to the Internet with the RPI, download files to the FAT-16 SD card, turn off the RPI, turn on the SX-1 and read the files in the card, I'll be more than happy!
If someone know more about the SX-1, please tell me. For example: which is exactly the power connector it uses? How to you power on/off (a button, or do you simple remove the power cord)? Can you do it with some control pin? There isn't much technical info around the SX-1 board :S
Idea: hybrid SX-1 + RPI 4
I didn't know about those wifi SD-cards, thanks! I'm not sure if they can be formatted FAT-16 (it could be, since some of them are directly running Linux), and I don't to always remember that I shouldn't erase the part of the SD where its SO and applications are stored.
But anyway, my idea is to share the card with the RPI to, for example, run openMSX with the files of the card, and at the same time being able to use the files (say, load ROM files) in the SX-1 FPGA, and of course being able to insert real cartridges.
If I manage to get that, I think it'll be a cool hardware: you can use openMSX using the SD card as a hard disk, and at the same time you can use "real" (FPGA) hardware.
I know I could simply use an emulator in the PC, and move the card from the PC to the FPGA to copy files, but I find the idea of the hybrid system quite cool 
With the known cartridge port for the GPIO, the result is an ergonomic posture for the Pi 400.
I think it would be better with some kind of 40 pin flat cable (regular ATA IDE cable unfortunately can't be used because it's female on both sides but the cable can be built by someone with right tools). The picture looks great and fun but quite dangerous in use because of the angled connection, which makes some uncomfortable feeling about that ...
Yes Ma'am!
My world will never be like before 
Yes Ma'am!
Haha!