Review on 🔌 RC-303 PCI Card with 2X Serial and 1X Parallel Port by Rosewill by Shane Jenkins

Modern computers are usually made without parallel ports because modern printers don't need them. But while USB interfaces are useful, they are serial and asynchronous. That's fine if you're doing something like printing and don't care if you stop for a moment or two and wait for the next package as long as it's delayed. However, if you drive very time-sensitive mechanisms, a synchronous interface (e.g. a parallel port) and a real-time kernel are the main requirements. Which brings us to modern CNC systems. A CNC milling machine consists of heavy pieces of metal and rotating cutters that are moved by large motors. A synchronous feedback loop constantly tells the computer where the milling head is, and the computer must respond to this feedback instantly and accurately to tell the mill when to change direction or where to move next. A loss of time during the cutting movement can mean that the cutting machine cuts too far or not far enough, resulting in a defective part. I am using this parallel port and realtime linux kernel to control my mill. And since I got this card (and got rid of the crappy USB to parallel adapter interface) I haven't had a single sync error. I wish I could drive out other types of bugs just as easily. So, hooray! That's right, it's even cheaper than a USB to parallel adapter and solves an expensive problem!