Is it possible to see the whole program?

Usually for each GOSUB, there's a RETURN

Code:
Start:
        Gosub Somewhere
        Gosub Elsewhere
        goto Start
        
Somewhere:
        HSERIN 2000, SomeWhereElse,[DataXYZ]
        Return
        
SomewhereElse:
        ToGGLE LED
        RETURN
        
ElseWhere:
        LCDOUT $FE,1,"Are AZERTY Keyboards still on the market???"
        RETURN
In Somewhere, if a timeout occure, it jump to SomewhereElse. This is basically a GOTO, BUT you need to use a RETURN to return to Start... or use a variant like...
Code:
Somewhere:
        HSERIN 2000, SomeWhereElse,[DataXYZ]

SomewhereEnd:        
        Return
        
SomewhereElse:
        ToGGLE LED
        Goto SomewhereEnd
HTH