The culmination of my commmunity college's CS103 class was learning the ins and outs of an ISA called MARIE. only 8 instructions & an editor+simulator written as a java app.
I had a lot of fun spending most of my time in that class writing an entire development stack for that architecture: assembler, simulator, debugger, and eventually a very barebones forth!
I had a lot of fun spending most of my time in that class writing an entire development stack for that architecture: assembler, simulator, debugger, and eventually a very barebones forth!