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631 flash doesn't keep high bit


New member
I just got my hand on several of the 631s today. They are beautiful and work really well.

I did notice one odd quirk. It seems that if you save to flash (command 4), you lose the high bit of any display data. For example, if you have a 208 (11010000 binary) on the screen (which is a kind of a hyphen but fills solidly) and save the screen as the boot state, on reset you'll have an 80 (01010000 binary) which is a 'P'.

Am I doing something wrong or is this just a limitation? Bug?
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USB LCD Displays - Graphic and Character LCDs with a Keypad

CF Support

What firmware version are the CFA-631's running?

I just tested one off the shelf with all the characters from 0 to 255, and found no corruption in any of the times between saving the boot state and rebooting the module.

CF Tech

We were able to confirm it on this end. It is corrected in the v2.0, which is currently shipping on the Blue ones. The red one are still shipping the old code.


New member
We've got them all installed already. It's not worth removing them, shipping them, and getting them back to re-install them. But it doesn't matter, we just won't use any such characters in our boot screen.

Thanks for the help.