Diagnostic Beep Codes                                   Faxback Doc. # 2410

The "BEEP CODES" are announced on the speaker if and only if a fatal
failure is detected.  For instance: "2-1-4" (A burst of two beeps, a single
beep, and a burst of 4 beeps) indicates a failure of bit 3 in the first 64K
of RAM. Beep codes are only used prior to screen initialization and screen
retrace. Once the screen has been verified, messages are written directly
to the Video Memory at 80000 & B8000 hex.

Note: This generalized listing is for most AT-Compatible computers. This
      listing should be used to determine only if a hardware problem exists.
      Servicing the equipment should still be done by a qualified Radio
      Shack Service Center.


   BEEP
   CODES   DESCRIPTION OF TEST OR FAILURE
-----------------------------------------------------------------------------
   none    80286 register test in progress or failure
   1-1-3   CMOS write/read test in progress or failure
   1-1-4   BIOS ROM checksum in progress or failure
   1-2-1   Programmable Interval Timer test in progress or failure
   1-2-2   DMA initialization in progress or failure
   1-2-3   DMA page register write/read test in progress or failure
   1-3-1   RAM refresh verification in progress or failure
   none    1st 64K RAM test in progress
   1-3-3   1st 64K RAM segment or data line failure, multi-bit
   1-3-4   1st 64K RAM odd/even logic failure
   1-4-1   1st 64K RAM address line failure
   1-4-2   1st 64K parity failure
   2-1-1   1st 64K RAM segment or data line failure, bit 0
   2-1-2   1st 64K RAM segment or data line failure, bit 1
   2-1-3   1st 64K RAM segment or data line failure, bit 2
   2-1-4   1st 64K RAM segment or data line failure, bit 3
   2-2-1   1st 64K RAM segment or data line failure, bit 4
   2-2-2   1st 64K RAM segment or data line failure, bit 5
   2-2-3   1st 64K RAM segment or data line failure, bit 6
   2-2-4   1st 64K RAM segment or data line failure, bit 7
   2-3-1   1st 64K RAM segment or data line failure, bit 8
   2-3-2   1st 64K RAM segment or data line failure, bit 9
   2-3-3   1st 64K RAM segment or data line failure, bit A
   2-3-4   1st 64K RAM segment or data line failure, bit B
   2-4-1   1st 64K RAM segment or data line failure, bit C
   2-4-2   1st 64K RAM segment or data line failure, bit D
   2-4-3   1st 64K RAM segment or data line failure, bit E
   2-4-4   1st 64K RAM segment or data line failure, bit F
   3-1-1   slave DMA register test in progress or failure
   3-1-2   master DMA register test in progress or failure
   3-1-3   master interrupt mask register test in progress or failure
   3-1-4   slave interrupt mask register test in progress or failure
   none    interrupt vector loading in progress
   3-2-4   keyboard controller test in progress or failure
   none    CMOS power-fail and checksum checks in progress or failure
   none    CMOS configuration information validation in progress
   3-3-4   screen memory test in progress or failure
   3-4-1   screen initialization in progress or failure
   3-4-2   screen retrace tests in progress or failure
   none    search for video ROM in progress
   none    screen believed operable
   none    monochrome screen believed operable
   none    40 column color screen believed operable
   none    80 column color screen believed operable

Two additional codes do not follow the above listed format, they are:

   long short long short   Indicates that no video board detected in system
   long long               Indicates that no boot device is available


(RJS/jej-06/28/94)