## AS8008S Assembler

####

       The  AS8008S assembler supports the 8008 microprocessor using
    the early MCS-8 assembly language syntax of a Fortan  based  as-
    sembler/simulator  (SIM-8)  which  had minimal lexical analysis.
    The instruction set contains a mnemonic for every  variation  of
    the basic instruction types.  As an example the load accumulator
    operation has a mnemonic for load a with a (laa), load a with  b
    (lab),  load  a with c (lac), load a with d (lad), load a with e
    (lae), load a with h (lah), and load a with l (lal).

####

    8008 REGISTER SET

    The following is a list of the 8008 registers used by AS8008S:

            a               -       8-bit accumulator
            b,c,d,e,h,l     -       8-bit registers
            c,z,s,p         -       status word bits

    8008 INSTRUCTION ADDRESSING MODES

       The  following  tables  list all 8008 mnemonics recognized by
    the AS8008S assembler.  The following list specifies the  format
    for each addressing mode supported by AS8008S:

        Instruction Mnemonic Syntax:

            r       register a,b,c,d,e,h,l

            c       status bits c,z,s,p

            M       memory access

            I       immediate access

        Instruction Argument Syntax:

            #data   immediate data
                    byte or word data

            label   call or jump label

            MMM     input/output port

    The terms data, label, and MMM may all be expressions.

       Note  that  not  all addressing modes may be valid with every
    instruction.  Refer to the 8008 technical data for valid modes.

####

    8008 INSTRUCTION SET

        Register Instructions
            Lrr
            LrM                     LMr
            LrI     #data           LMI     #data
            INr                     DCr

        Accumulator Group
            ADr                     ACr
            SUr                     SBr
            NDr                     XRr
            ORr                     CPr

            ADM                     ACM
            SUM                     SBM
            NDM                     XRM
            ORM                     CPM

            ADI     #data           ACI     #data
            SUI     #data           SBI     #data
            NDI     #data           XRI     #data
            ORI     #data           CPI     #data

        Rotate Instructions
            RLC                     RRC
            RAL                     RAR

        Progarm Counter and Stack Control Instructions
            JMP     label
            JFc     label           JTc     label

            CAL     label
            CFc     label           CTc     label

            RET
            RFc                     RTc

            RST

        Input/Outpu Instructions
            INP     MMM             OUT     MMM

        Machine Instruction
            HLT

        Combo Instruction
            SHL     #data  (load H and L with word #data)

##### Go to the Documentation Index

#### ... Exit the ASxxxx Documentation ... Home Page

###### Last Updated: March 2025