edition is often available for evaluation, though it defaults to the latest version. Legacy Support:

If you have MDK v5 installed, you should install version 4.7 into a separate folder to prevent file conflicts. The installer includes drivers for

: Older firmware codebases written for ARM7, ARM9, or early Cortex-M devices may require the specific compiler versions included in MDK 4.7.

int main(void) = (0x3<<20); // PC13 as output (on many Blue Pill boards)