SIC/XE ASSEMBLER

What is SIC/XE Machhine

• SIC Machine’s extended Edition
• you can read article at SIC/XE on wikipedia

  Function

• Control Section
• Addressing Mode (Flag bit)
  • Direct Addressing Mode
  • Indirect Addressing Mode
  • Simple Addressing Mode
  • Immediate Addressing Mode
  • Relative Addressing Mode
    • 1. Program Counter (PC Register)
    • 1. Base (Base Register)
• Extended Instruction (4bit Instruction)

How it works :

Using two passes …

• Pass one
  • Assign addresses to all statements in source code
  • Save values (addresses) assigned to labels for use in pass two
  • Process directives
• Pass two
  • Translate instructions
  • Convert labels to addresses
  • Generate values defined by BYTE and WORD
  • Process the directives not done in pass one
  • Write object code to output file

    Sample input :

    COPY START 0
    FIRST STL RETADR
    LDB #LENGTH
    BASE LENGTH
    CLOOP +JSUB RDREC
    LDA LENGTH
    COMP #0
    JEQ ENDFIL
    +JSUB WRREC
    J CLOOP
    ENDFIL LDA EOF
    STA BUFFER
    LDA #3
    STA LENGTH
    +JSUB WRREC
    J @RETADR
    EOF BYTE C'EOF'
    RETADR RESW 1
    LENGTH RESW 1
    BUFFER RESB 4096
    RDREC CLEAR X
    CLEAR A
    CLEAR S
    +LDT #4096
    RLOOP TD INPUT
    JEQ RLOOP
    RD INPUT
    COMPR A,S
    JEQ EXIT
    STCH BUFFER,X
    TIXR T
    JLT RLOOP
    EXIT STX LENGTH
    RSUB   
    INPUT BYTE X'F1'
    WRREC CLEAR X
    LDT LENGTH
    WLOOP TD OUTPUT
    JEQ WLOOP
    LDCH BUFFER,X
    WD OUTPUT
    TIXR T
    JLT WLOOP
    RSUB  
    OUTPUT BYTE X'05'
    END FIRST

Sample Output:

H^COPY  ^000000^001077
T^000000^10^17202D^69202D^4B101036^032026^290000
T^000010^10^332007^4B10105D^3F2FEC^032010^0F2016
T^000020^10^010003^0F200D^4B10105D^3E2003^454F46
T^001036^0D^B410^B400^B440^75101000^E32019
T^001043^0E^332FFA^DB2013^A004^332008^57C003
T^001051^0C^B850^3B2FEA^134000^4F0000^F1
T^00105D^0E^B410^774000^E32011^332FFA^53C003
T^00106B^0C^DF2008^B850^3B2FEF^4F0000^05
M^000007^05
M^000014^05
M^000027^05
E^000000