Apple ADB Keyboard recognized but no keys work?

[Fizzbinn]

So weird problem, I have an Apple ADB Keyboard (M0116) that has no problem starting a Quadra 700, the Apple Desktop Bus Mouse connected through it works fine, yet none of the keys are recognized... Key Caps shows it recognizes a standard ADB keyboard (as does TattleTech) so it's working to some level. Anyone have any ideas?

 

[Fizzbinn]

More data points, swapping in an Apple ADB Keyboard II works just fine for the Q700 and test the suspect Apple ADB Keyboard with my SE/30 also works fine. Back to the Q700, same issue, bizarre...

 

[Arbee]

The keyboard works 100% on the SE/30, but on the Q700 only the power key works? That's really strange.

 

[Fizzbinn]

Agreed.

Although the power key only works for the initial start-up kick-off, once booted when pressed it is not recognized by Key Caps, just like all the other keys. Yet TattleTech on the Q700 seeing the Standard Keyboard in its list of ADB devices and the mouse connected through it works just fine. The only thing coming to mind is some kind of power issue? I need to try the problematic keyboard on some more Macs for more data points I suppose...

 

[saybur]

It might be a power problem but it apparently works well enough to be detected and go through the whole ADB address dance routine, AFAIK it shouldn't show up in the OS at all if that fails.

You could try poking at it with ADB Parser and see what you get back. Try doing a Talk to register 3 to show if the keyboard microcontroller is still paying attention at all, or an ADB Reinit to see if it still is detected post-boot.

Might just be some weird software glitch too. Maybe boot off a different system disk and see if the behavior changes?

 

[Arbee]

The power key is both a key readable through the microcontroller and a directly connected switch with a dedicated pin on the ADB connector. So it's possible for it to turn the machine on even if the microcontroller is dead or missing. That said, clearly it's not dead since it works on the SE/30. Maybe the +5V power is off-spec on the Q700?

 

[saybur]

Possibly, but I'd expect that'd manifest as no keyboard detected. Must be some amount of working ADB comms to make TattleTech show it? Definitely very strange!

 

[Fizzbinn]

Got some time to play with this tonight. Suspect Apple ADB Keyboard with my Iici works just fine. Switching it back to the Q700 unchanged problem behavior.

Might just be some weird software glitch too. Maybe boot off a different system disk and see if the behavior changes?

My Q700 has 7.5.3 Rev 2 installed in its HD so I decided to boot off an Apple original 7.5.3 Disk Tools floppy see if that made a difference. I opened the HD copy of Key Caps and got an odd error message that I thought might be leading somewhere: "There is no description for this keyboard." Clicked "OK" and got a fun Key Caps app window.



(For some reason I did not try to actually enter text in something like SimpleText...)

I then repeated this booting from Apple original 7.6 Disk Tools floppy and got the exact same Key Caps result.

Back to booting off the HD and lo and behold the keys are all working, in Key Caps and everywhere else! Multiple reboots, warms and cold, still good. ...I mean that's great but I still have no idea what was going on. Sunspots? I have some more work with this Mac I want to do so I guess I'll be on the look out for a reoccurrence but in the mean time some Jurassic Mac appropriate fun.