Condition | Observed behaviour | Comment |
---|---|---|
All 4 banks are good | See the partial screen shot at here. | 2 banks of 256 KB + 2 banks of 64 KB = 640 KB |
Only bank 0 is populated, and all chips in it are good | See the partial screen shot at here. | 1 bank of 256 KB = 256 KB |
A single chip has failed, in bank 0 | See the partial screen shot at here. | Complete failure of chip (i.e. affecting all addresses in chip). See note 1 below. |
A single chip has failed, in bank 1 | "Bad memory 163 KB" is displayed. | 163 KB ??? |
A single chip has failed, in bank 2 | "Bad memory 163 KB" is displayed. | 163 KB ??? |
A single chip has failed, in bank 3 | The diagnostic will only find 576 KB of RAM. ("Found RAM: 576 KB") | |
RAM refreshed disabled | 1. "Found RAM: 640 KB" is displayed. 2. "Bad memory 163 KB" is displayed. 3. The bit error pattern shows the parity bit in error. |
163 KB ??? |
Type of EPROM for IBM 5160 | Size | Image download | Comment |
---|---|---|---|
27256/27C256 EPROM | 32 KB | Download | See note 2 below. |
W27E257 EEPROM | 32 KB | Download | See notes 2 and 3 below. |
Note 1 | It is possible for a RAM chip to fail in such a way that affects only some of the chip's addresses. Imagine such a chip in bank 0, one that fails at say the 5K address. That would result in the diagnostics 'Check first 2 KB of RAM' test passing. But the diagnostic will report an error later when testing the remainder of RAM. |
Note 2 | Ruud's Diagnostic ROM is actually only 8 KB in size. To create a 32 KB sized image, the 8 KB image was simply quadrupled. Therefore, the 32 KB sized image contains 4 instances of Ruud's Diagnostic ROM code. When the 32 KB sized EPROM is placed in socket U18, it will be the fourth instance that gets executed. (The first three are not used at all.) |
Note 3 | Regarding the programming/writing of an image into the W27E257: Even though the W27E257 is an EEPROM, rather than a 'traditional' EPROM, you will still need an EPROM programmer (or other) to program/write to the W27E257. That is because the IBM 5160 motherboard does not support programming/writing to EEPROM's in its sockets. |