AriCalculator is a home made pocket calculator.

[Dan]

The AriCalculator has an NXP S12 microcontroller with 240kB FLASH. I am considering porting the firmware to the NXP S12XEP100, which has an almost identical instruction set but more FLASH memory (1MB).

I can program it in assembly using the CodeWarrior IDE, which is free. CodeWarrior also has a "full-chip simulation" mode that allows you to debug your code without downloading it to the actual device, thereby saving the FLASH on the device from repeated writes.

I am wondering if there are similar microcontroller development environments, i.e. ones that are:

1) free
2) allow you to code in assembly with no code limitations, and
3) feature a simulation mode