| ??? 06/09/06 18:07 Read: times |
#118116 - Two methods Responding to: ???'s previous message |
1. Your device operates stand-alone. De-couple yourself from the downstream (original) PC keyboard and answer all the PC queries yourself. No timing issues with the downstream keyboard.
2. Opposite technique. Answer none of the PC queries yourself. When the PC talks to you, hold it off (one line low, can't recall which), send the same byte to the downstream keyboard, get response from downstream keyboard, echo that to PC. From what I've seen, the PC wiggles the lines like crazy during startup. You can't predict when one or the other or both of the lines are low or high. You just have to look for the CORRRECT sequence that indicates a valid data transfer and have timeouts built into your code for when the PC sends you on a wild goose chase. GB |
| Topic | Author | Date |
| what host does to PS/2 keyboard at boot? | 01/01/70 00:00 | |
| what host does to PS/2 keyboard at boot? | 01/01/70 00:00 | |
| different for different OS | 01/01/70 00:00 | |
| I think it's more a case of the BIOS | 01/01/70 00:00 | |
| further explanation | 01/01/70 00:00 | |
| Codes at startup | 01/01/70 00:00 | |
| startup codes | 01/01/70 00:00 | |
| Codes at startup | 01/01/70 00:00 | |
| Hold the lines low until KB startup | 01/01/70 00:00 | |
| use half of this | 01/01/70 00:00 | |
| Protocol and MORE | 01/01/70 00:00 | |
| Answer all PC queries | 01/01/70 00:00 | |
| yes | 01/01/70 00:00 | |
| Answer all PC queries | 01/01/70 00:00 | |
| Also check this link | 01/01/70 00:00 | |
| POR??? | 01/01/70 00:00 | |
| Re: POR??? | 01/01/70 00:00 | |
| Two methods | 01/01/70 00:00 | |
| ps2 | 01/01/70 00:00 | |
| eh? | 01/01/70 00:00 | |
problem pretty much resolved | 01/01/70 00:00 |