Do this program have any error

org 000h
jmp main
org 00bh
JMP TA
ORG 030H
MAIN: MOV TMOD,#01H
MOV TH0,#HIGH(5536)
MOV TL0,#LOW(5536)
SETB EA
SETB ET0
MOV B,#1010B
MOV R3,#100
SETB TR0


ALI: JNB P1.0,$
INC DPTR
JB P1.0,$
JMP ALI

TA: MOV TH0,#HIGH(5536)
MOV TL0,#LOW(5536)
DJNZ R3,SKIP
MOV A,DPL
MUL AB
MOV P2,A
MOV R0,B
MOV B,#1010B
MOV A,DPH
MUL AB
MOV B,R0
ADD A,B
MOV P3,A
MOV R3,#100
MOV DPTR,#0000H
skip: RETI

END


Q: What are the best simulators and debuggers for 89c51 (when programin with asm51) available free on the internet?
Q2: What is the difference between the AVR and MC.