Important Notice

The pages on this site contain documentation for very old MS-DOS software, purely for historical purposes. If you're looking for up-to-date documentation, particularly for programming, you should not rely on the information found here, as it will be woefully out of date.

   ◄Contents►  ◄Flags Summary►  ◄Register Summary►  ◄Register Setup►
──────────────────────────────────────────────────────────────────────────────
 
Accumulator         AX (AH/AL)    Multiply, divide, I/O, fast arithmetic
Base                BX (BH/BL)    Pointer to base address (data segment)
Count               CX (CH/CL)    Count for loops, repeats, and shifts
Data                DX (DH/DL)    Multiply, divide, and I/O
 
Source Index        SI            Source string and index pointer
Destination Index   DI            Destination string and index pointer
Base Pointer        BP            Pointer to base address (stack segment)
Stack Pointer       SP            Pointer to top of stack
 
Code Segment        CS            Flags                   Flags
Data Segment        DS            Instruction Pointer     IP
Stack Segment       SS
Extra Segment       ES
                                    -♦-