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(RS)
Select
Register
signal (RS)
Select
Register
and 18 control
registers
register
the address
register
level,
L o w
control
registers
level,
H i g h
of the
lowest
derivative
normally
a
Enable(El
is used
(E)
signal
Enable
CRTC
with
the
operation
HMCSSSOO
of the
derivative
normally
a
(lil
Reset
___
input
siglal (RES)
is
an
Reset
L o w
level,
When
RES
is
at
status.
following
~
in the
1)
the
counters
All
display operation.
the
stops
down
2)
All the
outputs
go
Control
in the
3)
registers
unchanged.
other HMCS6800
from
different
is
This
signal
and has restrictions
functions
following
RES
has
capability
1)
signal
L o w
level.
LPSTB
is
at
display operation
2)
the
The CRTC
starts
RTS
H i g h " .
signal
goes
Signals
CRT
Display
to
lnterfage
0
Clock.
QCLK)
Character
standard
clock
CLK
is
input
a
timing
for the CRTC
display operation.
derived from
the external
high-speed
Horizontal
(HSYNC)
Sync
HSYNC
is
active
an
for
horizontal
synchronization
(16,384
DYNAMIC
BIT
255;
'iff'
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Address
Selecn
'V~lE_..
level;
Low
level..
High
All manuals and user guides at all-guides.com
the address'
used
select
is
to
RS is
When
of the CRTC.
RS is
selected
and when
is
signal
selected.
This
are
of MPU address bus.
bit
(AO)
MPU
Rfw
in
signal
strobe
as
This
signal
intemal
registers.
clock.
System 95;
the CRTC.
used
to reset
signal
the
CRTC
into
forces
it
_
_
_
_
cleared
and the
device
CRTC
are
L o w
level;
to
and remain
affected
CRTC
not
are
LSls
in
family
for usage.
when
tiinction
only
of
reset
after
immediately
Device
which
defines character
signal
is
normally
This
signal
logic.
dot
timing
level
signal
which
provides
H i g h
device.
display
RAM)
*
Direct
A.
A,
H
A,
lj
B
address
For
2
one
thus_select
B
E)
COlllblI'lB.l11Ol.'l..
A0
A;
A
__\;o_c:
*
The
pin
the
data
write
mode,
the
read
mode,
NSYNC)
Vertical
Sync
active
VSYNC
is
an
for
at
cal
synchronization
at
(DISPTMG)
is
Display
Timing
active
DISPTMG
is
an
horizontal
display period
in
enable
video
to
necessary
level.
l ' l i g h "
is
Address
Refresh
Memory
refresh
MA0~MA,,
are
refresh
used
to
to
access
These
periodically.
screen
refresh
the
access.
memory
characters/screen
2000
to
_
(FlA0~RA4)
Address
Raster
RA4,~RA.,
raster
are
of
the
character
the
raster
etc.
generator
the
Display (CUDISP)
Cursor
CUDISP
is
active
an
the
display
to
cursor
hibited
while
DISPTMG
mixed
with
video
is
device.
(LPSTB)
Strobe
Light_Pen
active
LPSTB
is
an
detected
strobe
by
pulse
is
activated,
this
signal
shown
which
MAH)
are
stored
The
register.
pen
corrected
in
software,
pen, and
light
device,
light
l6l
of
access
line(A6~A6)
can
select
that
reason,
mode,
=l28
under
RAS
=l23
under
from
2
row
l28xl28=l6,384
from
one
state
corresponding
is
follows;
as
line
level;
Low
RAS...
level;
Low
row
CAS...
is
written
from
D.
l i l - I M
is
read
data
from
level
signal
which
provides
H i g h
device.
display
which
level
signal
H i g h
and vertical
scanning.
raster
when
DISPTMG
signal
only
(MA0~MA13)
_
address
signals
memory
in order
refresh
to
memory
16k
words
enables
outputs
these
for
applicable
So,
instance,
are
and
8-page
system.
used
which
address
signals
are
graphic
generator
or
level video
which
H i g h
signal
'This
the
CRT
output
screen.
on
l o w level.
Normally
is
at
the CRT
and
provided
to
signal
which
level
signal
H i g h
input
pen and control
circuit.
the
light
refresh
address
the
memory
in the 14-bit
2
stored
in
Fig.
are
address
need
refresh
memory
the
time
of
the
taking
delay
control
circuits
into
account.
pen
7
by
memory
be
done.
not
line
in
one
then
select
mode.
CAS
of
each
signal
selection
mode
selection
mode
in
RAM.
through
D
out
verti-
defines
the
It is
is
at
which
are
the CRT
max.
up
select
to
pattem
is used
is in-
this
output
display
accepts
When
(MA,,~
light
be
to
display
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