
Computer interfacing
The SIO (serial input/output device)
A serial input/output controller IC is available for the
Z80 CPU but it can, in fact, be used with a variety of other
microprocessors.
It provides two independent full-duplex channels with
separate control and status lines for modem and other
devices. The general facilities are much the same as those
already specified for the 6402 in respect of the format of
the data packet, that is the number of data bits, start
and stop bits, parity, etc. Data rates of up to 800 kbit/s
are possible with a 4 MHz clock. The usual types of er-
ror can be detected and flagged.
The El A 232 standard seria ...