an
octal code,
which
is read via the
keyboard
buffer
IC
1
by
the
input pin
12
.•.
19
of the
IC
4
(See
Circuit
Diagram
F).
A signal
is
recognized
as
correct
after
two
times scanning
for
one
time
key
operation.
The
octal
codes
(8
bits
data) of the
last
11
characters or functions
are
memorized
in
the
RAM
of
IC
4
as
the
key
operation
memory
(key
buffer
memory).
At
the
same
time, the 8
bits
data
in
the
IC
4 is the
address
for
the
command
which
is written
in
the
2K-ROM
(or
EPROM
IC
2).
The
command
makes
the
microcomputer
activating the
machine
functions
via the driver
circuit
and
the actuators.
3.04
Microcomputer
L
The
8
bits
microcomputer
8049
is a single chip type
computer
with
N-MOS
system.
It
is replaced during the introduction
by
the pin-
compatible microprocessor
8039
(Identification
IC
4
on
the control
circuit
board, see
Diagram
F)
with
external
EPROM
IC
2.
The
microcomputer is including the
ALU,
2K
x 8
bits
programme
memory,
1a3
x 8
bits
RAM
data
memory,
Zl
I/O
lines
(3x8
bits
I/O
ports, 1 interrupt input
and
2
test
inputs), multiplex address/data
bus.
The
internal clock generator
in
CPU
is clocked
by
means
of a
quartz with 6
MHz.
VCl
Xl
Al.I
Tl
CIOCK
~114!'1
WOR
l>S
12!o:
WORDS
'
P27
PROCiRAM
f).6,TA
;mm"
4
P~ft
Mf·MOR't
MEMORT
~
P~5
rnT
Pl4
·~
Pl7
im
'
1"ir"1
WR
Pl<
M
SIT
-\L~·
Pl.\
CPl'
080
Pll
ORI
Pll
082
PIO
ORJ
voo
084
PROG
OR5
P21
Tl~H.R
"
{)llf>
Pll
081
Pll
fVfNT
COllNH
R
vn
UNf.S
P20
Fig-I
Fig-2
The
IC
4 processes the information
from
the keyboard, the operation
keys
and
photo
interrupters
and
controls stepping motors
and
buzzer
(See
Circuit
Diagram
F).
7
I
_:_j
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