Read FIFO Sensor Memory - Specifies that a read from the data buffer register will input a byte from the FIFO memory and, if the 8279 is in the sensor mode, it indicates which row is to be read.This command is required before inputting data from the FIFO memory.Its format is:
Note that if the input mode is a keyboard scan mode, a read is always from the byte which first entered the FIFO, hence the I and AAA bits are ignored.
Write to Display Memory - Idicates that a write to the data buffer register will put data in the display memory.This command must be given before the CPU can send the characters to be displayed to the 8279. Its format is:
The 8279 provides two options for handling the situation in which more that one key is depressed at about the same time.