| Parent |
| • | There is a 20 second delay before anything is seen on the display. Be patient. <--- Do not fall for this trap |
| • | At power-on time, this AT version of the Supersoft/Landmark ROM's is known to erroneously beep the speaker with a 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. |
| • | 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 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. |
| 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 |
|
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 |
|
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 |
|
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 |
|
Symptoms can have a different cause. U116 is an example candidate. |
