Some of the early ZEC miner software supported CPU mining - but the GPU miners quickly outpaced CPU mining to the point it became UNPROFITABLE to bother trying to mine ZEC on a CPU.
I also suggest that if you want to do CPU mining, go Monero aka XMR (or use the NiceHash miner).
yeah nicehash miner will point you at hodl or xmr
maybe 25 cents a day extra.
Be carrefull !
NiceHash miner is only Windows compatible.
If you use Ubuntu (you don't write anything about your operating system), NiceHah don't work.