You're going to spend years just bootstrapping your metal refinery to the point where you can bootstrap your machine shop to the point where you can bootstrap your chemical industry to the point where you can produce undoped silicon of sufficient purity to make a decent integrated circuit. Sure, maybe you can slap together a handful of cheesy transistors to rival the first-ever transistor (Google up the picture of the first transistor; it's hilarious; you can practically smell the hot glue wafting from that picture) but it takes a bunch of transistors to make a computer, and you'd probably like your computer to get through three whole clock cycles before melting.

You might actually be better off just recapitulating history by starting with vacuum tubes. You'll need to master glassblowing and vacuum pumps to build semiconductors anyway, and tubes have lots of handy uses. (You could build an oscilloscope, which you will also need.) But you'll need to bootstrap your metal wire industry (generators aren't that hard to make if you can get hundreds of continuous feet of insulated wire...) and note that you'd better be very careful until you've had time to bootstrap your plastics industry; there are scary stories from the early days of TV when they had high-voltage circuits but nothing to insulate the wires with but varnish and paper...