Hi Mike, Yes, some 16x1 displays have weird addressing where the first 8 characters are in the address range 0x80 - 0x87 and the second set of 8 are in the range 0xc0 - 0xc7. 16x2 displays have contiguous addresses for each row. Yes, it is a pain in having to specify a starting address, sending out 8 bytes of data, and then having to specify a second starting address before sending out the next 8 bytes of data. I got the following out of a Seiko LCD data book: 16x1 display addresses ====================== 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0x80 0x81 0x82 0x83 0x84 0x85 0x86 0x87 0xc0 0xc1 0xc2 0xc3 0xc4 0xc5 0xc6 0xc7 16x2 display addresses ====================== 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 0x80 0x81 0x82 0x83 0x84 0x85 0x86 0x87 0x88 0x89 0x8a 0x8b 0x8c 0x8d 0x8e 0x8f 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 0xc0 0xc1 0xc2 0xc3 0xc4 0xc5 0xc6 0xc7 0xc8 0xc9 0xca 0xcb 0xcc 0xcd 0xce 0xcf Hope this helps! -Randie ________ Randie Ohtsji / ____/ /__ ____ ____ ___ _________ email: rohtsji@glenayre.com / /___/ / _ \/ __ \/ __ `/ / / / __/ _ \ Glenayre R & D / /_\ / / __/ / / / /_/ / /_/ / / / __/ Vancouver, B.C. CANADA \____/_/\___/_/ /_/\__,_/\__ /_/ \___/ Phone: (604) 293-1611 x4555 ________________________/ / Fax: (604) 293-4317 /_________________________/ > From mike@D-M-G.DEMON.CO.UK Wed Dec 17 05:59:36 1997 > >Hi, > > In my current project, I have to write to a 16x1 character LCD display > (the type based on the Hitachi 44781 (???) chip). > > I have done the development work on a 2x16 display using only the > top line. I have now connected my customers prefered display and it > seem like the line is split into 2, with the second group of 8 > characters appearing at some higher address. (ie 0x40). > > This means that I can't just write chars to the display, I have to > know when I go from the 8th to the 9th char and adjust the address > accordingly. > > I have not come across this before. Is this common? > > Thanks and regards, > > > Mike Watson >