\xcd\x03\x800\x01v\xe6_\xe5
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 . . . JR NC,$+3 ;0003 30 01 0 . HALT ;0005 76 V AND 05FH ;0006 E6 5F . _ PUSH HL ;0008 E5 .