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SOL-20 Repair and Restoration stump at troubleshooting

ihearta380

New Member
Joined
Oct 25, 2020
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4
Well I received this cool sol-20 computer that I am trying to restore. It was working when I received the computer and needed to replace the pads on the keyboard. I also replaced a hex inverter on the keyboard. However all I get is a blinking cursor and no keyboard response except for the three keys that have lights on them (local, shift, caps). Does anyone have any guess to where to start looking also what format is the data on the keyboard is this something I can interface the arduino to and create ASCII characters and see if its the keyboard or something else? I have a youtube video of my issue https://youtu.be/iE1HaG-F2mQ
 
Hi,

I have done an article on how aspects the SOL-2 keyboard functions and made a keyboard diagnostic tool, you could make an Arduino version of it, or just check initially if the keyboard is generating the correct output codes at its output connector. The diagnostic tool and details of the signals starts on page 19:

http://worldphaco.com/uploads/HARDWA...OR_THE_SOL.pdf

Hugo.
 
Hi,

I have done an article on how aspects the SOL-2 keyboard functions and made a keyboard diagnostic tool ...

Hugo.

Thank you for preparing this document. Excellent work. I have a non-SOL capacitive keyboard that I'm currently investigating; your diagnostic tool looks like something that I'm going to adapt for my own purposes :-}.
 
Thanks, you are welcome.

The codes generated are well documented in the SOL manual. There are also 4 lines that need checking /RST, /LOCAL, /BREAK and /STROBE, specifically worth checking that the /STROBE output pulse (its a narrow pulse) is present to alert the computer the output state is stable & ready. One helpful part of the keyboard design is that the output code(or character) from any key remains stable on the output after the key press so its easy to press a key and take as much time as you need to check for the correct output on lines B0 to B7.

As noted the /RST (computer reset) is generated by the Sol keyboard pressing the upper case and repeat keys together.
 
You will find that the link to the article I posted above has now stopped working. I was forced to re-create my website and the old URL's don't work (for now at lest) but if you go to the worldphaco.com website and hunt through the articles, you will find the one about the SOL-20 keyboard.


...the broken URL problem is now fixed.
 
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