Problem with bluemsx and meisei

To learn to know the bios of entry / exit, you must first learn assembleer.
To address this problem, you must first be tested with BASIC :

10 data 3e,01,cd,5f,00,cd,cc,00,c9,*
20 restore 10 : T=&HD000: Defusr=T
30 read X$: if X$="*" then a=usr(0):end
40 poke t,val( "&H"+X$) : t=t+1: goto 30

If this test  works on BASIC, it means that C does not return to BASIC, but to DOS. 

For now I have not studied the language C.
Goodbye