Originally Posted by BillKlineVT
The limitation I ran into was that the 1wire interface is too slow to do PWM if you are trying to emulate a PID control. Still works in a pinch though!
Yes, I wouldn't necessarily want to design it that way but if it was the only option I don't think it would be disastrous, you'd just need a fairly long cycle time.
The old fashioned way to control things from out the back of a PC was using the parallel port.
An intriguing option is to use the VGA port as an I2C connector
(cost: the price of a hacked monitor cable) and then expand to 16 I/O pins using a MCP23017
or similar. Apparently it doesn't work on windows though, or newer Macs.
Going back to the Cro Magnon era, BBC Micros were very good for this sort of thing.