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IBM 5170 (IBM AT) - Supersoft/Landmark Diagnostic ROM

WARNING:

The Supersoft/Landmark Diagnostic ROM is not known to detect RAM addressing problems. ( The POST in the IBM BIOS detects some. )

Version 1.2.0

This is the AT version of the diagnostic, intended for the IBM 5170 (IBM AT), IBM 5162, and clones.  Clone suitability will depend on how close the clone is to the IBM 5170.

If your computer is an AT clone, use the web page at here instead of this one.

An example screen output is shown at here.

On an IBM 5170 motherboard, sockets U27 and U47 are where the two Supersoft/Landmark ROM's need to be placed.

The 5170 motherboard requires EPROM's of type 27256 or 27C256 (or equivalent), speed rated per the 'Summary' section at here.
Burn the following images to such EPROM's, then place the EPROM's in sockets U27 and U47.

U27 image
U47 image

Click here to see some people/companies that can supply and program/burn EPROM's for you.


Important Notes:  <-------------

•	This AT version of the Supersoft/Landmark ROM contains a bug. At power-on time: - There is at least a 20 second delay before anything is seen on the display.  Be patient.     <--- Do not fall for this trap  - During that time, the speaker will beep out the error pattern that the user's manual (page 40/41) indicates "Cannot initialize monitor".
•	Some video cards will not work with this AT version of the Supersoft/Landmark ROM's. - My functional IBM MDA card does not work (no beeps, no display).  My second functional IBM MDA card does the same. - My IBM CGA card works. - My IBM EGA card (only 64 KB RAM fitted) will display, but poorly.  Supersoft appears to think that I have CGA. - My clone MDA card (unbranded) works. - My clone CGA card (unbranded) works. - My clone EGA card (an AST-3G) initially displays this, but then displays normally once the EGA memory test has finished. - None of my VGA cards work.  More information here.
•	Per the user manual, the MEMORY AT 000000 test will check conventional memory up to 640 KB, then test extended memory (address 1 MB onwards). The memory size figures in CMOS SETUP are ignored. At some point, the test will encounter memory that does not exist, and as a consequence, you will see errors. For example, if the only RAM is the 512 KB on the motherboard, then expect errors after address 80000.
•	On a 6 MHz 5170, the PROTECTED MODE CPU  test takes 25 seconds to complete.  Be patient.
•	On my fully functional IBM 5170 motherboards, the  PROTECTED MODE CPU  test does something odd.  Three things happen:     1. On the speaker, I hear the error pattern for "Cannot initialize monitor".     2. If I am using an IBM CGA video card, I see what appears to be 'CGA snow'.     3. "1 FAILED" is written to the top line.  (photo) The PROTECTED MODE CPU test is then indicated as "PASSED", then testing continues.
•	The FLOPPY READ  test takes about 1.5 minutes to fail.  Be patient.

Minor Notes:

•	The Supersoft/Landmark ROM's even generate a display if there is no RAM on the motherboard.  More information here.
•	The setting of the SW1 video switch on the 5170 motherboard does not matter.
•	No battery required.
•	There is nothing in the manual that indicates that the Supersoft/Landmark ROM's output POST codes.
•	With no keyboard connected, the  U126 KEYBOARD CONTROLLER and  KEYBOARD SCAN LINES  tests pass.
•	Operation of the A20 gate is not tested.  I was able to prove that by successfully running the Supersoft/Landmark with pin 22 of the 5170's keyboard controller disconnected (pin 22 = line P21).  With pin 22 disconnected, I was also able to prove that A20 gate operation is not required in order for the 5170 motherboard (fitted with IBM BIOS ROM's) to start, display POST output, then jump into BASIC.

Keyboard Controller:

By experimentation:

	IBM BIOS ROM	Supersoft/Landmark ROM's	Comment
Complete failure	POST displays nothing on-screen. Motherboard appears 'dead'. POST card shows 0C.	The  PROTECTED MODE CPU  test hangs (because a reset of the CPU via the keyboard controller cannot occur)	Symptoms can have a different cause
Partial failure - P21 driver (used for A20 gate)	POST displays on-screen Keyboard works. Motherboard can boot to BASIC	No error reported. Supersoft/Landmark ROM's appear not to test the A20 gate.
Partial failure - P26 driver (used for keyboard clock)	POST displays on-screen, but no keyboard operation	U126 KEYBOARD CONTROLLER  test =  Fail    KEYBOARD SCAN LINES  test =  Fail	Symptoms can have a different cause. U116 and U120 are example candidates.
Partial failure - P27 driver (used for keyboard data)	POST displays on-screen, but no keyboard operation	U126 KEYBOARD CONTROLLER  test =  Fail    KEYBOARD SCAN LINES  test =  Pass	Symptoms can have a different cause. U116 is an example candidate.
Partial failure - TEST0 receiver (used for keyboard clock)	POST displays on-screen, but no keyboard operation	U126 KEYBOARD CONTROLLER  test =  Fail    KEYBOARD SCAN LINES  test =  Fail	Symptoms can have a different cause. U116 and U120 are example candidates.
Partial failure - TEST1 receiver (used for keyboard data)	POST displays on-screen, but no keyboard operation	U126 KEYBOARD CONTROLLER  test =  Fail    KEYBOARD SCAN LINES  test =  Pass	Symptoms can have a different cause. U116 is an example candidate.