Dragons Awake

[binaryprose]

Last week i retrieved my old Dragon 32 from my parents house. My sister also had a Dragon, so i bought them both back to see if i could get them running..

They both fire up ok and display the Dragon Basic Message, but the keyboards on both seem to have problems. They either do not work at all, or if you press a key you get a different key on the same column. I am guessing this is a common problem so someone will be able to help me out.


Regards
Steven

[Lothos]

Hi - I retrieved mine and my brother's Dragons from our Dad's loft today.

No keyboard problems and both booted up and loaded cartridges which was nice to see. If you refer to Stig's World on YouTube he shows you how to clean the keyboard up which might solve the problem?

[binaryprose]

Thanks for the reply, glad to see the Dragons getting out at last.

[Stig]

The keys not working will just be a dirt issue, you will need to dismantle them and clean the contacts.

I'm not sure what the issue is with you getting the wrong character when a key is pressed, may be dirt related but I'm guessing it's not

Thanks for the shoutout there Lothos, Here is a link to the video in question. It doesn't really cover much detail on how to clean or dismantle the keyboards though.

https://www.youtube.com/watch?v=n-X6tqoY9EA

I also do a bit of work on a Dragon keyboard in this video but again, not much detail

https://www.youtube.com/watch?v=yN05VtAkcm8

[sixxie]

I'm not sure what the issue is with you getting the wrong character when a key is pressed, may be dirt related but I'm guessing it's not

Doesn't make much sense, but you could kinda imagine it if the keyboard connector was plugged in shifted by a position or two?

[prime]

I'm not sure what the issue is with you getting the wrong character when a key is pressed, may be dirt related but I'm guessing it's not

Doesn't make much sense, but you could kinda imagine it if the keyboard connector was plugged in shifted by a position or two?

The other thing that would do it is running a Dragon keyboard with a set of CoCo roms, or running a CoCo keyboard with a set of Dragon roms. Though probably not the case here tho.

Cheers.

Phill.

[binaryprose]

Its not the connector, I have checked that with a multi meter and they are both running stock roms. These machines worked last time I used them (1987). I was hoping this is a known issues...

[binaryprose]

I spent the whole weekend checking the keyboard based on the circuit diagram. all the keys work as they should. the wrong key being displayed sounds to me like a multiplexer issue....i.e. the hardware of the key scanning circuit.

[binaryprose]

I spoke to steve from DataServe (he fixes 8bit machine for a living) he said he had two dragon 32's with the exact same problem..

[prime]

Guess it could be the PIA I believe it's normally the left hand 6821, another possibility might be the 74LS244 that drives the printer port if that had failed and was pulling lines high or low when it shouldn't.

Might also be worth checking for shorts between the keyboard lines both on the board and in the cable / keyboard circuit board, as that can cause wrong keys to be pressed.

Cheers.

Phill.