Ralph - whilst it may not be prudent to 'post' the code - you can post the reference. If you detailed the issue number and year, then at least I could refer to the issue (i remember the article). Personally, I failed to see the use of what the author was describing - all the lcd modules I've used all seem to work the same way except for the contrast voltage - so why would I want to 'test' them?

I find your posts frustrating as what you ask is not necesarily related to your goal, so we go down a long winded path to find out what your goal is and suggest a path to it. What is you goal in this case? Build the test box as described in the article or something else?

What evidence do we have that a Commodore64 was used in a space flight? Was it used as a backup to the Atari for Missile Command?