I learned machine code in parallel with BASIC on this baby. But this was also a great hardware hacking platform. I bought one of the first CoCo Model I's when the came out for Xmas 1980. I performed all of my own upgrades to move from the original 4K memory to 64K, the maximum address space for the 6809 processor. Plus the expansion port in the side provided full access to the CPU, memory and computer subsystems. I finally used it as the development platform for a wireless weather monitoring station that I worked on for a senior project as part of a computer science engineering degree I recieved.