To all with interest in IBM 7090

On 8/11/2012 1:04 PM, Tony Duell wrote: Only if 3270 is. The 3270 / 52xx terminals put the smarts all in the controller. They vary little in that portion of the hardware in other than electrical connection. There is a stream of commands via channel or comms to the controller with the data out to the terminal and any keyboard commands / input streamed back. There is little of interest in what people call the terminal in most cases. The protocol out is continuous in nature as well. The return protocol reads modified fields from the terminal. If you do not position the cursor and prepare the terminal for input you get nothing. Neither of these are remotely problems with asynchronous serial terminals. With some multidrop terminals possibly, but the vast majority of serial protocols only have flow control both hardware and software, and the output can be completely random in both directions.