Sid1968 Posted September 11, 2019 Share Posted September 11, 2019 (edited) Hello Mates, i want to do the Alpha Lock / Joystick Fix as described here on my TI-99/4A: Alpha Lock / Joystick Fix The Problem is, that the Backsite of my Keyboard looks so totally different, that i dont know where i have to cut the conduction path and from where to where i have to wire the diode. I show you the fotos of my keyboards backside. Can you please sign in the foto where to cut and where to use the diode? Kind Regards Sid1968 Edited September 11, 2019 by Sid1968 Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted September 11, 2019 Share Posted September 11, 2019 like it says "The keyboard attaches to the TI motherboard with a 15 pin connector. The above picture shows the solder side of that connector. The yellow arrow is pointing at the number "6" connector. This is important because it this connector that the diode needs to be soldered too, and is the pin that one side of the alpha-lock switch connects to." so the number 6 connector on the top connects to the alpha lock at the bottom.. either meter it out (continuity tester?) to determine which trace it is or just put the diode near the plug at the top (I've done this) 2 Quote Link to comment Share on other sites More sharing options...
Sid1968 Posted September 11, 2019 Author Share Posted September 11, 2019 (edited) Thanks for the Foto and your advices. It would be nice if you would add one or two fotos that decribes what you talked about. If you want take my fotos to draw in. Edited September 11, 2019 by Sid1968 Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted September 11, 2019 Share Posted September 11, 2019 16 minutes ago, Sid1968 said: Thanks for the Foto and your advices. It would be nice if you would add one or two fotos that decribes what you talked about. If you want take my fotos to draw in. see that wire with the arrow pointed at it? unsolder that wire there, install diode in the solder hole, trim wire back a bit, strip it, solder stripe side of diode to wire..done much easier than trying to find the trace on that keyboard 1 1 Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted September 11, 2019 Share Posted September 11, 2019 or you could cut this trace and put it here.. that should also work 1 Quote Link to comment Share on other sites More sharing options...
unhuman Posted September 11, 2019 Share Posted September 11, 2019 I remember doing this as a kid and it worked for about 10 minutes. Once the computer was running for about 10 minutes, the fix would fail. IIRC, the keyboard would just go to all lowercase. So, I removed the fix. 1 Quote Link to comment Share on other sites More sharing options...
+Lee Stewart Posted September 11, 2019 Share Posted September 11, 2019 (edited) Per Greg’s posts, check that there is continuity between one of the solder points above or below the trace pointed to in the first picture and the solder point pointed to in the second. If that is OK, cut the trace pointed to in the first picture and bridge the cut trace with the diode as shown by the magenta diode graphic. ,,,lee Edited September 11, 2019 by Lee Stewart clarification 1 1 Quote Link to comment Share on other sites More sharing options...
+arcadeshopper Posted September 11, 2019 Share Posted September 11, 2019 1 hour ago, unhuman said: I remember doing this as a kid and it worked for about 10 minutes. Once the computer was running for about 10 minutes, the fix would fail. IIRC, the keyboard would just go to all lowercase. So, I removed the fix. sounds like a poor solder joint 1 Quote Link to comment Share on other sites More sharing options...
Sid1968 Posted September 12, 2019 Author Share Posted September 12, 2019 (edited) Thank you folks for the kind advices. The last night where looong... and i read your adviced not until now. I measured and came to this fully functional solution. I cutted the very short conduction path between the two points, where i soldered the diode. ? Edited September 12, 2019 by Sid1968 2 Quote Link to comment Share on other sites More sharing options...
Sid1968 Posted September 12, 2019 Author Share Posted September 12, 2019 (edited) 18 hours ago, unhuman said: I remember doing this as a kid and it worked for about 10 minutes. Once the computer was running for about 10 minutes, the fix would fail. IIRC, the keyboard would just go to all lowercase. So, I removed the fix. With the fix the TI-Keyboard behaves like a normal PC-Keyboard.... Press a Key and its lowercased... use it with SHIFT and you get the uppercase... ? Edited September 12, 2019 by Sid1968 Quote Link to comment Share on other sites More sharing options...
apersson850 Posted September 17, 2019 Share Posted September 17, 2019 That's true also without the fix. The fix takes care of the fact that the joysticks don't work in all directions if Alpha lock is down. I installed the diode almost 35 years ago, or so. It still works. 1 Quote Link to comment Share on other sites More sharing options...
Sid1968 Posted September 18, 2019 Author Share Posted September 18, 2019 Yes, what you wrote about the Alpha Lock is absolutely right, i forgot to mention that. Before i executed the fix i only had lowercase when pressing shift. It behaved vice versa to now. Quote Link to comment Share on other sites More sharing options...
apersson850 Posted September 21, 2019 Share Posted September 21, 2019 But no fix should be needed to get correct behaviour for upper and lower case letters. It's just to avoid the Alpha lock blocking the upwards movement of the joysticks. 3 1 Quote Link to comment Share on other sites More sharing options...
Sid1968 Posted October 2, 2019 Author Share Posted October 2, 2019 Hello folks, on the picture above, i show a photo where the diode is soldered the wrong way around. I must have chosen that photo accidentaly in the hurry. Here comes the right one. Sorry Mates. 3 1 Quote Link to comment Share on other sites More sharing options...
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