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92
93
164
All
and more about Sha
rp
PC
-1
500 at http:/lwww.PC-1500
.info
PC
-1500
•
so
~
S7
is
selected by the decoder
IC (TC40H138F) when the gate
signal input
MEO
(G1)
is
high,
Y1
(G2A) low, and G2B
is
low
(normally low).
SI
..
....
With high
..
. , low
so
as
to
(Yl)
se
lect the
opt
ional user RAM
ar
ea
....
PC-1500A
•
so
~
s7
is
selected by the decoder
IC
(TC40H138F) when the gate
signal Input
MEO
(G1)
Is
high,
Y1
(G2A) low, and G2B
is
low
(normally low).
SI
......
With hi
gh
..
. , low
so
as to
(YI)
select the user RAM area
....
S2
.
..
...
With low
....
the
S2
ou
t
put
S2
......
With low
...
, the
S2
out
put
(Y2) goes low so
as
to
select the (Y2) goes low
so
as
to select the
optional user
RAM
area. . . . u
se
r
RAM
ar
ea
.
...
S3
.....
. With low
...
, the S3
output
S3 . .
....
With low . . . , the S3 o
utput
(Y3) goes low so
as
to select the (Y3) goes low
so
as
to select the
u
se
r RAM area. . . . optional user RAM ar
ea
.
..
.
S4
......
With high
..
.,
the
S4
ou
t
put
54 .
....
. With high
...
. the
54
outp
ut
(Y 4) goes low
so
as to select the (Y 4) goes low
so
as to select
the
user
RAM
ar
ea
. . . .
op
tional user
RAM
area
....
55
..
. . . .
Do
not use
S7
.
...
. .
so
as to select the syst
em
-
(Y7)
RAM
(TC55 I 4)
..
.
Chip select signal
S5
..
....
Optional user R
AM
area
(Y5) (Address assignment
of
68QOH
~
6FFFH)
S7
.....
. so as to select the system
(Y7) RAM
(HM6
11
6)
...
Chip select signal for the PC-1
SOOA
Refer to following chart for the PC-
I 500A.
Do
not sell this PDF !! !
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