Ferguson Institute Online Div. of Jmlit

Assignment #14
I/O FUNDAMENTALS:  
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1.  I/O chips:  I/O chips called Peripheral Interface Adapters (PIAs)  DDR have data direction register(s)  that indicate the direction  (in or out) that data will flow for the present instruction.   The current type of control signal will determine the present data direction.  Also, recall that in 3 state data transfer the decoded instruction's resulting control signal is used to help select which I/O chip to activate.  The data bus is also connected to the I/O chip's data pins.  In the lab we used a wire-wrapping tool to wire each data bus line to the I/O port's data pins. Recall also that all or a portion of the instructions destination address is placed on the address bus to be multiplexed into a chip-select signal of the I/O port.(....see 3 state transfer)  they have ...

2.  I/o boards:  There are I/O boards for loading various types of files; video boards, sound boards,  parallel port data boards, often used for transferring data to the ptinter, serial boards for  telecommunication,  and often have I/O ports on them.   

3.  Parallel, series, video, sound, USB:   Data flow may br parallel ot serial as RS232