86Box/src/cpu/x86_ops_bcd.h

static int opAAA(uint32_t fetchdat)
{
        flags_rebuild();
        if ((flags & A_FLAG) || ((AL & 0xF) > 9))
        {
                AL += 6;
                AH++;
                flags |= (A_FLAG | C_FLAG);
        }
        else
                flags &= ~(A_FLAG | C_FLAG);
        AL &= 0xF;
        CLOCK_CYCLES(is486 ? 3 : 4);
        PREFETCH_RUN(is486 ? 3 : 4, 1, -1, 0,0,0,0, 0);
        return 0;
}

static int opAAD(uint32_t fetchdat)
{
        int base = getbytef();
        if (cpu_manufacturer != MANU_INTEL) base = 10;
        AL = (AH * base) + AL;
        AH = 0;
        setznp16(AX);
        CLOCK_CYCLES((is486) ? 14 : 19);
        PREFETCH_RUN(is486 ? 14 : 19, 2, -1, 0,0,0,0, 0);
        return 0;
}

static int opAAM(uint32_t fetchdat)
{
        int base = getbytef();
        if (!base || cpu_manufacturer != MANU_INTEL) base = 10;
        AH = AL / base;
        AL %= base;
        setznp16(AX);
        CLOCK_CYCLES((is486) ? 15 : 17);
        PREFETCH_RUN(is486 ? 15 : 17, 2, -1, 0,0,0,0, 0);
        return 0;
}

static int opAAS(uint32_t fetchdat)
{
        flags_rebuild();
        if ((flags & A_FLAG) || ((AL & 0xF) > 9))
        {
                AL -= 6;
                AH--;
                flags |= (A_FLAG | C_FLAG);
        }
        else
                flags &= ~(A_FLAG | C_FLAG);
        AL &= 0xF;
        CLOCK_CYCLES(is486 ? 3 : 4);
        PREFETCH_RUN(is486 ? 3 : 4, 1, -1, 0,0,0,0, 0);
        return 0;
}

static int opDAA(uint32_t fetchdat)
{
        uint16_t tempw;
        
        flags_rebuild();
        if ((flags & A_FLAG) || ((AL & 0xf) > 9))
        {
                int tempi = ((uint16_t)AL) + 6;
                AL += 6;
                flags |= A_FLAG;
                if (tempi & 0x100) flags |= C_FLAG;
        }
        if ((flags & C_FLAG) || (AL > 0x9f))
        {
                AL += 0x60;
                flags |= C_FLAG;
        }

        tempw = flags & (C_FLAG | A_FLAG);
        setznp8(AL);
        flags_rebuild();
        flags |= tempw;
        CLOCK_CYCLES(4);
        PREFETCH_RUN(4, 1, -1, 0,0,0,0, 0);
        
        return 0;
}

static int opDAS(uint32_t fetchdat)
{
        uint16_t tempw;

        flags_rebuild();
        if ((flags & A_FLAG) || ((AL & 0xf) > 9))
        {
                int tempi = ((uint16_t)AL) - 6;
                AL -= 6;
                flags |= A_FLAG;
                if (tempi & 0x100) flags |= C_FLAG;
        }
        if ((flags & C_FLAG) || (AL > 0x9f))
        {
                AL -= 0x60;
                flags |= C_FLAG;
        }

        tempw = flags & (C_FLAG | A_FLAG);
        setznp8(AL);
        flags_rebuild();
        flags |= tempw;
        CLOCK_CYCLES(4);
        PREFETCH_RUN(4, 1, -1, 0,0,0,0, 0);
        
        return 0;
}