my idea of badnop is to have the compiler and feel of the system relatively architecture-free, but still enable the target languages to be very architecture dependant and 'close to the metal'. PIC18F ------ this is the central 8 bit architecture. it's a real dream to write an 8 bit forth for. very nice general purpose chip. PIC10F/PIC12F/PIC16F -------------------- i'm not a big fan of the smaller cores, assembly code wize. plus, they are not self-programming, which makes interactive coding impossible without special programming hardware. the previous version of badnop supported the 12F/16F chips. i never programmed a 10F. both of the architectures have their use for very small, cost sensitive, mass produced apps. they are very nice chips all in all, but do not map so well to forth as the 18f cores, and are better programmed in assembler: due to the somewhat weird architecture, they require a lot of tricks which only tend to pay off for small apps. AVR --- i started out with pic due to lower entry threshold. availability of DIP packages, liberal sample policy, and availability of an expert friend were the key reasons to choose PIC over the seemingly more popular AVR. since i'm very happy with PIC, and have a fairly optimized 18f target, i doubt i will ever switch to AVR except when i'm externally forced to do so. overall, what i read about AVR's advantages over PIC did not make me curious enough to this date. after all, it's not an afternoon job to write an AVR port of badnop with similar optimization. for a very good comparison, see: http://www.electricstuff.co.uk/picvsavr.html note a lot of the issues mike addresses are solved in the 18f series. the main reason for most people i know to use AVR is the availability of a gcc compiler. since C is one of the things i'm explicitly trying to avoid, the remaining reasons are not really compelling. good advice i heard: if your app is not too cost sensitive, pick an architecture and stick with it: knowing a chip in & out pays more than going for the 'best chip'. Z80 --- yes :) for obvious reasons. there's this MSX in an fpga being developped by some dutch guys. i like this chip. it's weird, it's the original cause of my interest in electronics. maybe a little vanity run. since i only have an old MSX to hook up, this is really only for when i want to stick my head in the sand for a while. it's also not a harvard architecture. DSPIC30F -------- together with the other 16bit data path cores, this seems like a very interesting chip to use. available in small DIP packages, ideal for small hacks. it's on my wish list, and is going to be the main pull app to make badnop more general/portable to larger bit widths. ARM7TDMI -------- seems to be the de facto standard for 32 bit microcontrollers. these are a bit faster than the 16bit microchip cores, and have the advantage of a 32bit data path. cost about the same. there are already a lot of forth implementations for these. this is on my wish list too, though currently postponed because i can only get access to them as 70 euro modules, not in standalone DIP packages, means i need to aquire some soldering skills first :) 68K and Coldfire ---------------- since you can find these in a lot of old palm OS devices, and those are easy to find, and 68K is just about everywhere else, it might be an interesting target for recycling purposes. the SCF5250 DSC seems a nice target.