Slightly off topic, but I'm looking forward to FPGA tooling improving to the point where I can build a fantasy personal computer based on dragging and dropping architectural components into a design that compiles to hardware.<p>I'm definitely too lazy to design from scratch or build by hand, and there's already so much out there designed for FPGAs, so just hoping one day it may be plug and play like the Mister is for entire systems.
I kind of want to try to make a "74 series logic" RISC V CPU at some point so I can inherit the compiler.<p>It's rough building the larger systems though. All the early logic is still around for the most part, but most of the "medium integration" parts have disappeared. Things like register files and bitslice ALUs. (74x181, etc.)
Somebody is way too into solderless breadboards.<p>I can see building a CPU from smaller components, but not dealing with loose connections in that mess.
Those register names seem to be 8008-inspired:<p><pre><code> A (0): GP register/arg 0
B (1): GP register/arg 1
C (2): GP register/arg 2
D (3): GP register/arg 3
L (4): GP register/(L)ow index register
H (5): GP register/(H)igh index register
</code></pre>
It claims to be a "RISC architecture" but the instructions are 1-3 bytes variable length, which is also more similar to the 8008 and other early 8-bit CPUs.
> <i>Designed for 4 MHz clock speed, ~100-150k instructions/second</i> [1]<p>Given the scale of the breadboarded rat's nest prototype, was this actually achieved?<p>[1] <a href="https://github.com/jdah/jdh-8/blob/c621a9980a7d4eb7aa4debc6245827628818aa19/SPEC.txt#L11" rel="nofollow">https://github.com/jdah/jdh-8/blob/c621a9980a7d4eb7aa4debc62...</a>
Neat! But shouldn't this rather be called a nanocomputer? Minicomputers could still fill a room at their time [1]. Our desktop machines are “microcomputers”.<p>[1]: <a href="https://www.computerhistory.org/revolution/minicomputers/11/333" rel="nofollow">https://www.computerhistory.org/revolution/minicomputers/11/...</a>