He was an IBM salesman after the Navy and prior to founding EDS, it's very unlikely he ever wrote any software. I've read a fair bit about him over my lifetime

He was an IBM salesman after the Navy and prior to founding EDS, it's very unlikely he ever wrote any software. I've read a fair bit about him over my lifetime and have never run across a mention of him being technically inclined, an engineer, writing software, etc. He understood how the IT services industry worked - from his time on the inside of it at IBM - and saw an opportunity. He likely had a good salesman's grasp of the structure of the industry technologically (what was selling, what wasn't; who dominated what segments; what companies were spending on various segments). He got started from spotting a market inefficiency that IBM wasn't interested in pursuing (leasing unused compute time), so Perot formed EDS and the rest is history.