Sharp MZ-3500 - Manual (Page 65)

6-3. Block diagram of the interface
MZ3S00
Peripheral
6-4. System switch functions
ON OFF
SW5 Causes an error when the
ER signal is low or open
during data output.
ER signal is disabled.
SW6 Always high when power is
on to the main unit.
The CD signal is set high
while data output, but
would not be set high
when the echo-back
furKtion is selected for
the host computer.
SW7 Causes on error when the
PO signal is high during
data output.
Polarity is inverted.
6-5. 8251AC controls
There are two control words for the 8251 AC.
(1) Mode instruction: Defining general operational para­
meters, such as unit, stop bit, etc.
(2) Command instruction: Defining status words used for
actual operation, such as send/receive enable, etc.
1) Definition of generation operational parameters
• Baud rate
• Character size
• Even/odd/off parity assignment
-•Stop bit size
'Corresponds to channel command of BASIC.
c
START
J
8251AC internal reset
8251AC mode instruction
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