ROMPT
ʽ:        @ <,> PROMPT <ַʽ>
               [MESSAGE <ַʽ>]
    佫ָλʾڲ˵ PROMPT ַ
ʱ, Դʽ. ɹƶƲ˵ѡ. 
ĳһʾ PROMPT λʱ, Էɫʾ, 
Ӧ MESSAGE ַʾϢ. Ϣ SET MESSAGE TO
ָ.
KEYBOARD
ݴ̻
ʽ:        KEYBOARD <expc>
    佫 <expc> ַм̻, Чȼڼ
ַ̼.
MENU
ùѡ˵
ʽ:    MENU TO <memvar>
     @... PROMPT  ʹ, ÷  READ  
@...SAY...GET, Ϊ˵, ѡ˵Ŵ <memvar>
.
SAVE SCREEN 
ĻϢ.
ʽ:    SAVE SCREEN [TO <memvar>]
    ñ䱣ĻϢ,  RESTORE SCREEN .
RESTOR SCREEN 
ָ SAVE SCREEN ĻϢ
ʽ:    RESTORE SCREEN [FROM <mem-var>]
    ʹñ,  SAVE SCREEN  ĻϢ.
