Asteroids Error Codes

 RAM Failure is indicated by a sequence of from 1 to 6 tones.
 A low-frequency tone is heard for each good RAM chip.  A much
 lower frequency is heard for a  failing RAM chip.  The sequence
 stops with the last failing RAM chip.  To restart the sequence,
 press the Reset pushbutton on the game PCB or set the self-test
 switch to off, then again to the ON position.  Identify the bad
 RAM chip with the table below.  Example:  Three tones, then
 a tone of much lower frequency indicates failure of RAM chip R4.

    Tone     RAM Chip Location
   ----------------------------
      1            D2
      2            E2
      3            M4
      4            R4
      5            N4
      6            P4

 ROM/PROM Failure is indicated by two columns or lines of numbers
 in the upper left-hand corner of the display.  The number in the
 left column or first line indicates the failing ROM/PROM chip(s).
 Identify the bad ROM/PROM with the table below.
 The number in the right column or second line indicates the
 failing data bit of the failing ROM/PROM.  Identify the bad bit
 with the second table below.  If more than one bit is failing,
 the displayed number(s) are hexadecimal combinations of the
 numbers shown below.  Examples:
       1) If bits D2 and D3 fail, C is displayed.
       2) If bits D2, D3 and D7 fail, 8C is displayed.
       3) If bits D4 and D5 fail, 30 is displayed.
       4) If bits D1, D3, D5 and D6 fail, 6A is displayed.

   Displayed No.       Failing ROM/PROM
  -----------------------------------------------------
                 -05 & -06 PCB       -03 & -04 PCB

        0            N/P3          N/P3  K4,L4
        1            N/P3          N/P3  K4,L4

        2             J2            F1   F2,L1   F2,H1
        3             J2            F1   F2,L1   L2,L1

        4             H2           D/E1  H2,J1   H2,J1
        5             H2           D/E1  H2,J1   M2,M1

        6            E/F2           C1   K1,J2   J2,K1
        7            E/F2           C1   K1,J2   N2,N1

   Displayed No.     Failing Bit
  -------------------------------
         1               D0
         2               D1
         4               D2
         8               D3
        10               D4
        20               D5
        40               D6
        80               D7


   RAMSEL signal failure is indicated by a BANK ERROR or
   PAGE SELECT ERROR message at lower middle of display.