I don't know assembly, personally. However, it may be eaier for those who do to help you if you edit your original post to put the source code in {code} {/code} blocks, with { and } replaced by ...

It’s a tool that could make taking the leap into assembly code just that little bit easier. For another taste of bare metal coding, check out [Ben Jojo]’s discussion of x86 bootloaders.

Just don’t go too far back. Programming the EDSAC, TUTAC, or the 4004 is probably not representative of modern computing at all. Honestly, none of these CPUs are.