Advertisement
1.
MPU Peripheral
MPU
operatesby
EXTAL
The
generator.
Address
board
peripheral
data
bus
is
connegted
through
buffer
NMI
Eid
keyboard.
pin
for
Timer
interrupt.
MPU
operation
stops
MPU
in
this
period.
2.
Timing
Signal
System
signals
are
clock
pulse
from
crystal
2.016
MHZ
clock
pulse
signal
and
generator
Signal
Gerneration.
the
By
E
signal
(l.OO8
clock
output
pulse
signals
used
for
are
is
outputted
from
clock)
this
by
signal.
Horizontal
and
vertical
bridge
the
data
between
3.
RAM
Block
RAM
block
consist
Store
RAM.
Colour
the
signal
receipt
colour
register
.
4.
Video
Signal
Generator
Program
RAM
data
is
parallel
as
a
signals,
version,
these
serial
thereby
RAM,
making
the
colour
display.
the
On
other
hand,
signal
by
monochrome
to
monochrome
display.
5.
Keyboard
MB-6890
the
hardware
use
zontal
synchronize
decoder
IC86
HD74l59P
:
this
By
scanningL_we
keyboard
input,
IRQ
is
ware
procedure
done
make
the
keyboard
input
way.
Cirucit
signal
(4.032MCK)
signal
of
MPU
circuit,
extension
to
RAM
expansion
pin
is
used
to
BREAK
is
used
to
detect
By
applying
Low
temporarily
address
Generator
in
clock
generated
oscillator,
obtained.
are
4.032
is
MHZ
for
MHZ)
outputted
(l6.l28
MHZ),
RAS
RAM
driving
purpose.
signal
system
generator
CRTC
generates
synchronise
signals
MPU.
of
32KB=l6KBxl6
Programme,.
RAM
and
Program
RAM
and
sending
between
from
outputted
character
then
converted
signals
mixed
are
seperate
colour
video
colour
video
separate
mixture
video
signal
method.
scan
signal
and
their
equal
output
and
multiplexer
detect
the
input
can
interrupt
is
generated
by
IRQ
process
possible
even
which
is
supplied
is
supplied
to
CRTC,
terminal
through
address
terminal
and
expansion
interrupt
from
input
of
the
keyboard
level
signal
from
bus
and
data
bus
by
generator
dividing
16.128
8.064
MHZ,
From
these,
16.128
the
EXTAL
signal
and
by_MPU
system
CAS
signals
are
generated.
At
the
same
to
CRTC
(This
the
Address
(MA,RA)
and
cursor
Store
RAM
the
address,
occupy
same
colour
RAM
and
MPU
generator
or
to
serial
signals.
with
the
colour
signals,
which
signal
becomes
circuit,
generator
This
method
is
done
frequency
HP
signal,
(IC9O
:
from
the
keyboard.
to
MPU.
this
By
subrutine.'
Also,
if
other
data
procedure
by
timing
signal
ROM,
RAM,
key-
buffer
and
terminal
trace
counter
and
and
pin
is
FIRQ
outside
to
DMA/BREQ,
is
from
separated
256
32,
MHZ
4.032
MHZ,
MHZ
and
is
MHZ
for
timing
to
MPU
and
Video
signal
generated
These
two
time,
CHRCK
signal
signal
is
master
signals,
display
signals
and
and
l6KBx5
Colour
therefore,
is
done
through
graphic
generator
After
this
con-
signals
from
colour
supplied
to
are
monochrome
video
then
is
Supplied
by
counting
hori-
then
scanning
HD74LSl5lP)
input.
detecting
By
interrupt,
soft-
E56
interrupt
method
is
under
the
Advertisement
