Condition | Observed behaviour | Comment |
---|---|---|
All 4 banks are good | See the partial screen shot at here. | 4 banks of 16 KB = 64 KB |
Only bank 0 is populated, and all chips in it are good | See the partial screen shot at here. | 1 bank of 16 KB = 16 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 | Either "Bad memory 163 KB" is displayed, or only 16 KB of RAM is found ("Found RAM: 16 KB"). | 163 KB ??? |
A single chip has failed, in bank 2 | Either "Bad memory 163 KB" is displayed, or only 32 KB of RAM is found ("Found RAM: 32 KB"). | 163 KB ??? |
A single chip has failed, in bank 3 | The diagnostic will only find 48 KB of RAM. ("Found RAM: 48 KB") | |
RAM refreshed disabled | 1. "Found RAM: 64 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 5150 | Size | Image download | Photo | Comment |
---|---|---|---|---|
MCM68766 EPROM | 8 KB | Download | ||
2564 EPROM | 8 KB | Download | Photo | 2564, not 2764 |
With adapter, 2764/27C64 EPROM | 8 KB | Download | Click here for adapter. | |
With adapter, 27128/27C128 EPROM | 16 KB | Download | Click here for adapter. See note 1 below. | |
With adapter, 27256/27C256 EPROM | 32 KB | Download | Photo | Click here for adapter. See note 1 below. |
With adapter, W27E257 EEPROM | 32 KB | Download | Click here for adapter. See notes 1 and 2 below. |
Note 1 | Ruud's Diagnostic ROM for the PC and XT is actually only 8 KB in size. To create a 16 KB sized image, the 8 KB image was simply doubled. To create a 32 KB sized image, the 8 KB image was simply quadrupled. |
Note 2 | 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 5150 motherboard does not support programming/writing to EEPROM's in its sockets. |