HP-42S LCD details

[Thomas Okken]

(10-09-2019 06:27 AM)jpcuzzourt Wrote:  I've browsed the Free42 sources, but didn't find anything I could recognize offhand yet, and it doesn't seem to have emulated the self-tests. Why on Earth not?

It has no hardware so there's nothing for it to test.

An idea of a test function that turns on all the elements of the display at once, for testing skin layouts, has been floating around on and off my to-do list for ages, but never got done. It's easy enough to test skins without it, I guess...

You're familiar with the 131x16 pixel dot-matrix part; the only other parts are the seven status annunciators. In order from left to right, they are ▼▲, Shift, Printer, Busy, Low Battery, G, and RAD. Out of all these, only the Low Battery annunciator is a bit of a pain in the rear to test, due to the absence of the aforementioned test instruction. You actually have to run down the battery for it to turn on.

To see all seven with their relative positions, take a look at a skin like Erik Ehrling's large 42S, https://thomasokken.com/free42/skins/des...ng42sl.gif along the bottom.