opcodes

Due to this, the only opcodes which touch RAM in such a design are load and store opcodes, and they only use the simplest addressing modes.

Assembly language provides one level of abstraction: instead of dealing with opcodes directly, the programmer uses mnemonic names for the instructions, which the assembler converts into the opcodes.

Not that a portable program has any business trying to read instruction opcodes in the first place.

He even made alterations to make it easier to control the LMC using opcodes rather than Assembly.

Some of the 1-byte opcodes are specific subsets of instructions (e.g., 04 is ADD AL, Ib).

Of course the 6502 was a beautifully simple design with a minimal set of opcodes.

That's non-trivial, especially if most of the opcodes can be implemented more quickly than this.

There is one next step - eliminate jump_table and rewrite your bytecode before executing it, replacing opcodes with the jump addresses.

As already suggested, function pointers are a particularly memory inefficient way to represent instructions/opcodes.

On top of that whats inside the Field itself doesn't actually matter to anyone provided the same read/write opcodes do the right thing(s).

I've been wondering what were the worst decisions in assigning single-byte opcodes; can you determine that from your data?

From the A86 manual: A86 takes advantage of situations in which more than one set of opcodes can be generated for the same instruction.

The "no complex opcodes" thing was sometimes taken to extremes: There's no single-cycle algorithm for integer multiplication or division.

Sorry, but now I reflexively flag-on-sight any instance if this clickbaity, obviously overstated "every programmer needs to know about semiconductor opcodes/mainframe architecture/etc".

This is taken to an extreme in accumulator-based designs, which aren't used much now but were previously very popular: One "main" register which is involved in all (or nearly all) opcodes, maybe a couple index registers to make memory addressing easier, and everything else is in RAM.

The key to the multiple ways of doing things is to make code clearer - you have to look at it not so much as "there's more than one way to do the same thing" as "many things compile down to the same opcodes on the VM".