4 ms·
This was a well known trick for 8080s and Z80s as far back as the 1970s. Back then there were a lot of assembly programmers, tricks like this were stock in trad
by billforsternz 11y ago
This was a well known trick for 8080s and Z80s as far back as the 1970s. Back then there were a lot of assembly programmers, tricks like this were stock in trade.
- bro-stick 11y agoReminds me of optimizing microcode back in uni... From the reference implementation of 134 microinstructions down to 61, and it was far more cycle-efficient as well (progressive decoding and Huffman encoded micro representation given sample programs). Since it was a contest for two goals of extra credit, people were pissed that our team captured both. It took about 30 hours to implement. Microinstructione are like a CPU's firmware which implements the external-facing macroinstruction set into a simpler set of microinstructions which coordinate various internal state.