Definitely, if you just want implement one in a HDL. For instance the RISC-V ISA has been implemented multiple times in various languages [for instance: <a href="https:&#x2F;&#x2F;github.com&#x2F;ucb-bar&#x2F;riscv-sodor" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;ucb-bar&#x2F;riscv-sodor</a>]. RISC-V is quite a bit more complex than the 4004 ISA.<p>If you want to DIY the entire chip, as in manually lay out the transistors, I suppose it can be done if you have quite a bit of experience in electrical engineering, but it&#x27;d be rather cumbersome given the &#x27;modern&#x27; (as far as HDL tooling is modern) tooling that is already available.