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| WARNING: | If your 16KB-64KB motherboard has a RAM related problem, the Supersoft/Landmark Diagnostic ROM is known to display incorrect and misleading information. It is though the Supersoft/Landmark Diagnostic ROM is not intended for the 16KB-64KB version of IBM 5150 motherboard. Click here for a list of known bugs. For the 16KB-64KB motherboard, if you want to see if RAM bank 0 is good, then I suggest that you use Ruud's diagnostic ROM. |
| Bank 0: | 16 KB sized, | addressed 0000 to 3FFF hex | ( 0 KB to 16 KB) (soldered to motherboard) |
| Bank 1: | 16 KB sized, | addressed 4000 to 7FFF hex | (16 KB to 32 KB) (socketed) |
| Bank 2: | 16 KB sized, | addressed 8000 to BFFF hex | (32 KB to 48 KB) (socketed) |
| Bank 3: | 16 KB sized, | addressed C000 to FFFF hex | (48 KB to 64 KB) (socketed) |
| U33 image for a 2764 EPROM (or 27C64) in a MK36000/2764 adapter | ( or in 2364/2764 adapter, such as the one at here ) |
| U33 image for a 27128 EPROM (or 27C128) in a MK36000/27128 adapter | ( or in 2364/27128 adapter, such as the one at here ) |
| U33 image for a 27256 EPROM (or 27C256) in a MK36000/27256 adapter | ( or in 2364/27256 adapter, such as the one at here ) |
| U33 image for a 27512 EPROM (or 27C512) in a MK36000/27512 adapter | ( or in 2364/27512 adapter, such as the one at here ) |
| • | Read the earlier warning about RAM related bugs. |
| • | Some video cards will not work with this PC (and XT) version of the Supersoft/Landmark ROM. - My IBM MDA card works. - My IBM CGA card works. - My IBM EGA card will display, but poorly. - My unbranded clone MDA card works. - My unbranded clone CGA card works. - None of my VGA cards work. More information here. |
| • | If a RAM error at address 05040 is reported, note that the "05040" bit is incorrect. Do not believe the "05040" - the diagnostics have displayed the wrong address. |
| • | The SYSTEM MEMORY TO 10000 test will fail if 64 KB (10000 hex = 64K) of RAM is not fitted. So, that is 64 KB on the motherboard (all four RAM banks populated). RAM related switches on the motherboard are ignored (switches SW1:3 and SW1:4, and SW2). |
| • | The KEYBOARD CONTROLLER test will fail if no PC-class keyboard is connected to the 5150 motherboard. |
| • | The FLOPPY CONTROLLER test requires that a floppy controller card is fitted to the 5150 motherboard. For this test, the card does not need any drives connected to it. |
| • | The FLOPPY READ test takes about 1.5 minutes to fail. Be patient. |
| • | The NONMASKABLE INTERRUPT test is known to fail if either: - Math coprocessor (8087 chip) is absent and you have switch 2 on SW1 in the wrong position for that (off). - Math coprocessor (8087 chip) is present and is faulty. |
| • | The U28 ROM test is expected to fail, because there is nothing in the U28 socket. |
| • | It is observed that when a test fails, the Supersoft/Landmark ROM switches the motherboard relay on/off three times. (The clicks are very audible.) |
| • | The settings of the switches within SW1 on the 5150 motherboard are ignored, except for switch 2. |
| • | The settings of the switches within SW2 on the 5150 motherboard are ignored. |
| • | Switches 3 and 4 within SW1 on the IBM 5150 motherboard do not enable/disable RAM banks. The 4 motherboard banks are always enabled. That is why in the IBM 5150, all motherboard RAM banks must be populated before RAM is added via expansion card/s. |
| • | Ignore the box labelled, "XT SW1". That is for when the ROM is used in an IBM 5160 (IBM XT). |
| • | The term 'KEYBOARD CONTROLLER' is misleading. Unlike the IBM 5170, the IBM 5150 does not have a keyboard controller chip. Discrete components are used instead. |
| • | There is nothing in the manual that indicates that codes are sent to port 80h. |
| • | An example output is shown at here. |
