found this on reddit.. not sure if it will help but here it is
Your virtual memory card (“VMU”) is full, so you either need to swap the vmu or delete saves in one of the vmus. To do this while playing a Dreamcast game, press and hold all 4 face buttons (a, b, c/x and d/y) and START at the same time, this will open the Dreamcast’s VMU manager where you can select from your 4 memory cards and delete saves to free up space.
You have got the VMU files within the folder reicast/.local/share/reciast
I recommend to copy the files to a new one wit different name an then delete the saved games in the original files. This way you don't lose any saved game, you just need to rename files again to acess older saved games.
In order to delete files is very simple bu not obvious. Run reicast and instead of selecting a game file just cancel. You will run the bios then and will be able to manage the VMU.
I did read the Info to late that i can activate a State Window whit "c" so maybe its time for another Dreamcast Video but now whit FPS?
And i wonder how much different there is between the Pandora (1ghz) Version and the Pyra Release, whe are still struggeling whit Audio Driver over CPU, so its allready a miracle whe get that playable Emulation, but i cant test on my Pandora as its a 700 mhz Device and my right Shoulderbutton Trigger is broken...
EDIT: To show FPS i need to change the cfg file, but what dos "C" show? something whit CPU, is it CPU Work then?
I dit input the showFPS in the Reicast Config File, but nothing happened, i dont know, did i something wrong? i put a few sentences after the = 1 yes and i think also on but when i did run Sonic Advanture, nothing happened, or would this fps meter only apear after the intro of the game?