Large custom fonts in 8080 parallel mode

I made some custom numeric characters that are 7 bytes wide and 92 pixels tall.  In serial mode, they all display perfectly, but are too slow to keep up with my volume control operation. So I switched to 8080 parallel mode. Using your routines for custom characters (1 or 2 bytes wide and 11 pixels tall), I have my giant characters displaying perfectly for about 35 lines, then for no reason, the character starts at the top again and shifted to the left by a bunch of pixes, then after about another 35 pixes, it starts again at the top of the character, but the x is lined up again.  Also, it doesnt matter if I shift the y axis up or down, it still resets the y after the same number of rows are displayed.

Is there a limitation or something I should now about the OLED_WriteMemoryStart_160128RGB() command that you cant use it for over a maximum size area? 

 I have only 1 character loaded in ram (after the icon data)...its a 6. (I get the same results with other characters). 

// Large Font Start
const unsigned char chr_f7s_30[] =         // 7 bytes per row 53 pixels wide
{
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0xFF,
0x80, 0x00, 0x00, 0x00, 0x00, 0x1F, 0xFF, 0xF0, 0x00, 0x00, 0x00, 0x00, 0x7F, 0xFF, 0xFE, 0x00,
0x00, 0x00, 0x01, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x03, 0xFF, 0xFF, 0xFF, 0x80, 0x00, 0x00,
0x07, 0xFF, 0xFF, 0xFF, 0xC0, 0x00, 0x00, 0x0F, 0xFF, 0xFF, 0xFF, 0xE0, 0x00, 0x00, 0x1F, 0xFF,
0xFF, 0xFF, 0xF0, 0x00, 0x00, 0x3F, 0xFF, 0x01, 0xFF, 0xF8, 0x00, 0x00, 0x7F, 0xF8, 0x00, 0x7F,
0xF8, 0x00, 0x00, 0x7F, 0xF0, 0x00, 0x1F, 0xFC, 0x00, 0x00, 0xFF, 0xC0, 0x00, 0x0F, 0xFC, 0x00,
0x01, 0xFF, 0xC0, 0x00, 0x07, 0xFE, 0x00, 0x01, 0xFF, 0x80, 0x00, 0x07, 0xFE, 0x00, 0x01, 0xFF,
0x00, 0x00, 0x03, 0xFE, 0x00, 0x03, 0xFF, 0x00, 0x00, 0x03, 0xFF, 0x00, 0x03, 0xFE, 0x00, 0x00,
0x03, 0xFF, 0x00, 0x07, 0xFE, 0x00, 0x00, 0x01, 0xFF, 0x00, 0x07, 0xFC, 0x00, 0x00, 0x01, 0xF0,
0x00, 0x07, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, 0xF8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0F,
0xF8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0F, 0xF8, 0x00, 0x00, 0x00, 0x00, 0x00, 0x0F, 0xF8, 0x00,
0x00, 0x00, 0x00, 0x00, 0x0F, 0xF8, 0x00, 0xFF, 0x80, 0x00, 0x00, 0x0F, 0xF0, 0x07, 0xFF, 0xF0,
0x00, 0x00, 0x0F, 0xF0, 0x1F, 0xFF, 0xFC, 0x00, 0x00, 0x1F, 0xF0, 0x7F, 0xFF, 0xFF, 0x00, 0x00,
0x1F, 0xF0, 0xFF, 0xFF, 0xFF, 0x80, 0x00, 0x1F, 0xF1, 0xFF, 0xFF, 0xFF, 0xC0, 0x00, 0x1F, 0xF3,
0xFF, 0xFF, 0xFF, 0xE0, 0x00, 0x1F, 0xF7, 0xFF, 0xFF, 0xFF, 0xF0, 0x00, 0x1F, 0xFF, 0xFC, 0x03,
0xFF, 0xF8, 0x00, 0x1F, 0xFF, 0xF0, 0x00, 0x7F, 0xFC, 0x00, 0x1F, 0xFF, 0xC0, 0x00, 0x1F, 0xFC,
0x00, 0x1F, 0xFF, 0x80, 0x00, 0x0F, 0xFE, 0x00, 0x1F, 0xFF, 0x00, 0x00, 0x07, 0xFE, 0x00, 0x1F,
0xFE, 0x00, 0x00, 0x03, 0xFF, 0x00, 0x1F, 0xFC, 0x00, 0x00, 0x03, 0xFF, 0x00, 0x1F, 0xF8, 0x00,
0x00, 0x01, 0xFF, 0x00, 0x1F, 0xF8, 0x00, 0x00, 0x01, 0xFF, 0x00, 0x1F, 0xF8, 0x00, 0x00, 0x01,
0xFF, 0x80, 0x1F, 0xF0, 0x00, 0x00, 0x00, 0xFF, 0x80, 0x1F, 0xF0, 0x00, 0x00, 0x00, 0xFF, 0x80,
0x1F, 0xF0, 0x00, 0x00, 0x00, 0xFF, 0x80, 0x1F, 0xF0, 0x00, 0x00, 0x00, 0xFF, 0x80, 0x0F, 0xF0,
0x00, 0x00, 0x00, 0xFF, 0x80, 0x0F, 0xF0, 0x00, 0x00, 0x00, 0xFF, 0x80, 0x0F, 0xF0, 0x00, 0x00,
0x00, 0xFF, 0x80, 0x0F, 0xF0, 0x00, 0x00, 0x00, 0xFF, 0x80, 0x0F, 0xF8, 0x00, 0x00, 0x00, 0xFF,
0x80, 0x07, 0xF8, 0x00, 0x00, 0x01, 0xFF, 0x80, 0x07, 0xF8, 0x00, 0x00, 0x01, 0xFF, 0x00, 0x07,
0xFC, 0x00, 0x00, 0x01, 0xFF, 0x00, 0x07, 0xFC, 0x00, 0x00, 0x03, 0xFF, 0x00, 0x03, 0xFE, 0x00,
0x00, 0x03, 0xFE, 0x00, 0x03, 0xFE, 0x00, 0x00, 0x07, 0xFE, 0x00, 0x01, 0xFF, 0x00, 0x00, 0x07,
0xFE, 0x00, 0x01, 0xFF, 0x80, 0x00, 0x0F, 0xFC, 0x00, 0x00, 0xFF, 0xC0, 0x00, 0x1F, 0xFC, 0x00,
0x00, 0xFF, 0xF0, 0x00, 0x7F, 0xF8, 0x00, 0x00, 0x7F, 0xFC, 0x03, 0xFF, 0xF0, 0x00, 0x00, 0x3F,
0xFF, 0xFF, 0xFF, 0xF0, 0x00, 0x00, 0x1F, 0xFF, 0xFF, 0xFF, 0xE0, 0x00, 0x00, 0x0F, 0xFF, 0xFF,
0xFF, 0xC0, 0x00, 0x00, 0x07, 0xFF, 0xFF, 0xFF, 0x80, 0x00, 0x00, 0x01, 0xFF, 0xFF, 0xFE, 0x00,
0x00, 0x00, 0x00, 0xFF, 0xFF, 0xFC, 0x00, 0x00, 0x00, 0x00, 0x1F, 0xFF, 0xE0, 0x00, 0x00, 0x00,
0x00, 0x03, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
};
//Large Font End

My routine:

 void OLED_LargeFont_160128RGB(unsigned long textColor, unsigned long backgroundColor)    // function to show Large font character
{
    int i;
    int count;
    unsigned char index = 0;
    unsigned char y_pos = 118;  //was 118
    unsigned char mask = 0x80;
       
   for(i=0;i<92;i++)     // display large font character
    {
        OLED_SetPosition_160128RGB(51,y_pos);
        OLED_WriteMemoryStart_160128RGB();
        for (count=0;count<8;count++)
        {
            if((chr_f7s_30[index] & mask) == mask)
                OLED_Pixel_160128RGB(textColor);
            else
                OLED_Pixel_160128RGB(backgroundColor);
            mask = mask >> 1;
        }
        index++;
        mask = 0x80;
        for (count=0;count<8;count++)
        {
            if((chr_f7s_30[index] & mask) == mask)
                OLED_Pixel_160128RGB(textColor);
            else
                OLED_Pixel_160128RGB(backgroundColor);
            mask = mask >> 1;
        }
        index++;
        mask = 0x80;
                for (count=0;count<8;count++)
        {
            if((chr_f7s_30[index] & mask) == mask)
                OLED_Pixel_160128RGB(textColor);
            else
                OLED_Pixel_160128RGB(backgroundColor);
            mask = mask >> 1;
        }
        index++;
        mask = 0x80;
                for (count=0;count<8;count++)
        {
            if((chr_f7s_30[index] & mask) == mask)
                OLED_Pixel_160128RGB(textColor);
            else
                OLED_Pixel_160128RGB(backgroundColor);
            mask = mask >> 1;
        }
        index++;
        mask = 0x80;
               for (count=0;count<8;count++)
        {
            if((chr_f7s_30[index] & mask) == mask)
                OLED_Pixel_160128RGB(textColor);
            else
                OLED_Pixel_160128RGB(backgroundColor);
            mask = mask >> 1;
        }
        index++;
        mask = 0x80;
                for (count=0;count<8;count++)
        {
            if((chr_f7s_30[index] & mask) == mask)
                OLED_Pixel_160128RGB(textColor);
            else
                OLED_Pixel_160128RGB(backgroundColor);
            mask = mask >> 1;
        }
        index++;
        mask = 0x80;
                for (count=0;count<8;count++)
        {
            if((chr_f7s_30[index] & mask) == mask)
                OLED_Pixel_160128RGB(textColor);
            else
                OLED_Pixel_160128RGB(backgroundColor);
            mask = mask >> 1;
        }
        index++;
        mask = 0x80;
        y_pos--;
   }
//   index = 0;
//   y_pos = 118;
}


Thanks!!!

Also, the character seems still to paint slowly....do you have any suggestions for a faster giant character write?