Thanks for the help. I forgot to mention that this unit is encased and is serial controlled. It only requires 5Volts, Ground and a serial feed. I guess I can assume it uses the opcodes as per the Noritake data sheet and that there would not be anything else on the front end that would require different commands. However, I read that it uses an Epson chipset and not Hitachi. I'll have to compare the commands and see if there are differences. I like the idea about auto incrementating the display intensity however I never really thought that they fade over time. I hope I have not bought a worn out display. I have not received it yet. Oh well, it was fairly cheap. Any further advice around asynchronous serial control would be appreciated. Thanks.