Sharp mz-800 Instrukcja Obsługi Strona 30

  • Pobierz
  • Dodaj do moich podręczników
  • Drukuj
  • Strona
    / 71
  • Spis treści
  • BOOKMARKI
  • Oceniono. / 5. Na podstawie oceny klientów
Przeglądanie stron 29
MZ-800
Key strobe is issued
through
PAo-PAl
to
~can
the key.
As
it
is supplied
to
the decoder,
it
makes one
of
outputs,
0-9,
set low. It is then added
to
the
key
matrix
to
scan
the
line
of
the key depressed (vertical key
matrix
scan).
The
line is in
the
low
state,
if
it
is in depression
(horizontal key
matrix
scan).
NOTE: In the ready
for
command
state, PAo-PAl are
normally
repeats
to
be
low
state and the decod-
er outputs repeats
to
be high state. But, since
the decoder is
of
an open collector type, it
would
not
permit
to
check high and
low
state.
b) Cassette
control
Decoder side
"H"
Strobe signal
lJ
~ey
8255 switch
PB
side
The 8255 issues
the
cassette
write
data
from
PC, and
Example
8255 output PA,
PA
2
PA,
PAo
L H L L
Only the LS145 decoder output 4
(#5
pin) is in
low
state.
Because the connector
(5)
is in
low
state, key scan is permitted only for
keys, A through
H.
State
of
the 8255 input
port
B.
PB
7
PB.
PBs
PB. PB,
PB
2
PB,
PB
o
L H H H L H H L
Above stata shows that keys,
A,
E,
or
H,
is in depression.
read signal
through
PC5.
The type
of
data (input,
output) and its
format
are
as
follows:
___
~I
I I
.
I'
SHORT
~
CASE
1
READ
EDGE
READ
POINT
LONG
LONG
represents the
bit
value
"'"
and SHORT the
bit
value
"0".
Data
will
be
read at 368 microseconds after
(
SHORT
10
seconds
220CO
TAPE
MARK
1
LONG
40
LONG
SHORT
40
TAPE
MARK
LONG
20
SHORT
20
1-1. INFORMATION
BLOCK
128
bytes
1
DATA
BLOCK
29
READ
POINT
i
SHORT
(HIGH) 240,.S
(LOW) 278,.S
LONG
(HIGH) 470,.S
(LOW) 494,.S
READ
POINT
379,.S
the
signal rising edge. Data are recorded in repetition
of
LONG and SHORT, and
the
same data are
written
twice.
Check
SHORT
INFORMATION
Check
SHORT
sum,
1
256
BLOCK
sum,
1
2 bytes
bytes
128 bytes
2 bytes
5 seconds
LONG
LONG
11000
Check
SHORT
DATA
Check
sum
1
256
BLOCK
sum, 1
2 bytes
bytes
2 bytes
LONG
LONG
Przeglądanie stron 29
1 2 ... 25 26 27 28 29 30 31 32 33 34 35 ... 70 71

Komentarze do niniejszej Instrukcji

Brak uwag