Pioneer PX-7 Service Manual page 5

PX-7
Memory
Configuration
Address
Slot
#0
Slot
#1
Slot
#2
Slot
#3
Expansion
I/O
register
Expansion
slot
(rear
of
unit)
1.4
I/O
MAP
(1)
I/O address
allocation
RW
Details
Remarks
&H98
W
Data
write into
TMS9129NL
VRAM
or
R
Data
read
from
equivalent
VRAM
&H99
W
Command,
address
set
R
Status
read
&HA0
W
Address
latch
AY-3-8910
&HA1
W
Data write or
&HA2
R
Data
read
equivalent
&HA8
W
Port
A
data write
8255A
or
R
Port
A
data read
equivalent
&HA9
W
Port
B
data write
R
Port
B
data read
&HAA
W
Port
C
data write
R
Port
C
data read
&HAB
W
Mode
set
&H90
W
Strobe output
(bO) latch output
R
Status input (bl)
"1"
is
BUSY
&H91
W
Print data
latch output
I/O
addresses
from
80
to
FF
area prescribed
as
above
for
system
use.
Empty
columns
are
system
reserves.
*1/0
addresses
marked
with an
asterisk
are for
optional
equipment.