\xe5\xcd\x03\x800\x01v<G\x87\x87\x87\x90
Note that non-ascii characters in the above source code will be escaped (such as \x9f).
Disassemble:
ORG 00000H PUSH HL ;0000 E5 . CALL 08003H ;0001 CD 03 80 . . . JR NC,$+3 ;0004 30 01 0 . HALT ;0006 76 V INC A ;0007 3C < LD B,A ;0008 47 G ADD A,A ;0009 87 . ADD A,A ;000A 87 . ADD A,A ;000B 87 . SUB B ;000C 90 .