Bob, This is where I was just headed....I am sure my menus are chewing up alot of ROM. It was when I added onboard diagnostics when I started running into the out of space issues. Thanks for the reinforcement of this idea. - Ted -----Original Message----- From: Bob Ammerman [mailto:rammerman@ADELPHIA.NET] Sent: Tuesday, July 22, 2003 5:40 AM To: PICLIST@MITVMA.MIT.EDU Subject: Re: Out of ROM PIC18F452 ....what do to? If a large portion of that 16K is taken up by constant data structures (like menu definitions and character strings), look into simple compression schemes for them. You can often save tremendous amounts of space by using data-driven code rather than a lot of repeated procedural stuff. Bob Ammerman RAm Systems ----- Original Message ----- From: "Ishaan Dalal" To: Sent: Tuesday, July 22, 2003 1:08 AM Subject: Re: Out of ROM PIC18F452 ....what do to? > You might want to use an external NVSRAM. Maxim/Dallas make NVSRAMs that > have access times of 85 ns -- it might fit your bill at the 10 MIPS speed of > the 18F. > > Or, if you can graduate beyond DIP parts, the 64/80-pin 18Fs might fit your > bill. For example, the 18F8620 has 32k-words (2 x 18F452) and the 18F8720 > has 64kwords. These also have external memory interfaces (i.e. dedicated > data bus/address lines, I think) to which you can just add the NVSRAM I > mentioned above without any "glue" code. > > Lastly, as someone already suggested, switch to assembly, though it may not > be practical if you already have C code that generates >16kwords of ASM. > > Cheers, > Ishaan > > -- > http://www.piclist.com hint: The list server can filter out subtopics > (like ads or off topics) for you. See http://www.piclist.com/#topics > -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics -- http://www.piclist.com hint: The list server can filter out subtopics (like ads or off topics) for you. See http://www.piclist.com/#topics