Sharp MZ-5500 Tehnical Manual page 27

11) When accessing the 1/0 port of the A Y·3-8912
(2) When initializing the lOA port, write the data to be
sound le), load rIo register address into 231 H, then
output (described above), then place the port in the
wr
ite the 1/0 da ta to 230H.
output mode. This is needed to maintain the SE land
MOTOR ON signals inactive during initialization .
*1/0 address area shown in the table below may differ between the MZ-5500 and
the MZ-5600.
Table 2
-30..
MI. -5500.
AFTER INITIAL
OEVICE AOO
BIT SIGNAL NAME 1/0
P/O
OEFAULT
PO RT -C 070H 100
WRCT Oedicated cassette Write signal (No use'
(LS175)
101
MOTOR
Oedicated cassel1e Motor signal (No use'
OUT
Indefinite
102
---------­
103 FOCRST
F OC Reset signal (reset when one.)
PO f-H -B
nOH 100
RDCT
Oedicated cassette Read signal (No use)
(LS125)
101
SEr,J SE
Oedici:!ted cass e tte Sense signal (No use)
Input
IN
(0 :
SW OFF , 1 : SW ON and C.PU)
mode
102 DIP SW7
SW7 } System DIP Switches (See page.l
103 DIP SW8
SW8
TL\.ble.
2 - 3b
MZ -
5&00
DEVICE
AOO
BIT
Signel name 1/0
After power on Initialize
100
~
PORT -C
070H
101
~
OUT Oon't care
(LS74)
102 High Den MF 0 • 1 M/640K alternate signal
103 FOCRST FOC reset signal (reset with "1'"
100
~
PORT-B
270H
101
----­
IN
("0" - SW OFF "1" ­
SW~ON
&
CPU) Input mode
(LS367)
102 DIP SW7
SW7 }
103
DIP SWS SW8
System DIP SW (See separate page'