Added Assembler 4004 and update Assembler 8051 (#1537)

* Added Assembler 4004

* Update Assembler 8051

a/Assembler 8051.asm

@@ -0,0 +1,28 @@
+ORG 00H
+SJMP INIT
+
+INIT:
+; Timer1 as the UART1 buadrate generator
+        MOV TMOD, #20H  ; Timer1, 8-bit auto-reload mode
+        MOV TH1,  #0FDH ; 9600 baudrate at 11.0592MHz
+        MOV SCON, #50H  ; Serial mode 1, enable reception
+        SETB TR1        ; Start Timer1
+        MOV DPTR, #20H  ; Point DPTR to the start of the string
+
+SEND:
+        CLR A
+        MOVC A, @A+DPTR ; Get the next character
+        INC DPTR
+        JZ DONE         ; End program if the character is null
+        MOV SBUF, A     ; Send the character
+        JNB TI, $       ; Wait for transmission to complete
+        CLR TI          ; Clear TI flag
+        SJMP SEND
+
+DONE:
+        SJMP $          ; Endless loop
+
+ORG 20H
+DB 'Hello World', 0
+
+END