\xcd\x03\x80\xd8\xff\xcd\x03\x80\xc7v
Note that non-ascii characters in the above source code will be escaped (such as \x9f).
Disassemble:
ORG 00000H CALL 08003H ;0000 CD 03 80 . . . RET C ;0003 D8 . RST 38H ;0004 FF . CALL 08003H ;0005 CD 03 80 . . . RST 0 ;0008 C7 . HALT ;0009 76 V