Mike,

Don't let the naysayers discourage you.

Erik goes nonlinear every time someone suggests using something on which the paint is already dry. There are lots of ways to do lots of things. This is YOUR project, and YOU should get to decide how it's to be done. If you want to use a part or several, that have been in the parts drawer for a year or ten, it's YOUR choice. Some people will complain because it's not what they would do, but they aren't the ones who'll have to do the work.

I'd suggest you carefully consider what you're going to do, starting with the functions that you will require. Then I'd consider implementation options.

As far as code loaders, I'd recommend you look at the doc package that comes with Ultramon51 (try this URL <http://www.dtweed.com/circuitce...cro1.html> )
to see about having MCU-loadable code space, and read the doc and source code for PAULMON at www.pjrc.com for more info on how to use FLASH memory in conjunction with a monitor. Both of these will probably answer some questions for you.

I like Ultramon51 because it has that built-in line-by-line assembler and disassembler, kind of like what's in DEBUG.EXE, if you remember what DOS was. IIRC, both PAULMON and ULTRAMON51 allow you to download code to executable space. Ultramon combines the code and data spaces by effectively ORing nRD with nPSEN as an enable to the external memory. It is not "rocket science."

RE