Advertisement
INTERACTIVE PLAY OPERATION
ll'lrrfROOU(,TION
ln1eractive operation
requires
the
use
of
a
computer J)fogram,
Vir1...any
any
compu1er with
an
RS232·C
or
SCSI
incerface
can con1rol
the
VP41S
usin&
a
high-level
laniuage
s
uch
as BASIC or
PASCAL.
11.e relevant
connection al the rear
of
lhe VP4U
slloald
be
used lo
tQl!ned
the
~I computer.
The required program
ff loaded
into the
rotnpulerr;y51emintheusualway
It
is
001
possil>le
to
simullaneously control
lhe
player
via
both
the
RS232-C
and
the SCSI bus. Mode
selection
mu51
be made
by
the
master
(host
c~puter) to determine the mode
of communica1ion;
the
playtritselfc11nnotmakethisselection. lnitiallychcptaycrisinthc
F-code
oommunication
mode (~ia RS232-C)
and the
SCSI bus
is
switchedofr.
1-'-(0t>I-:
OPERATION VIA
RSZJ2·C
This
mode
is
au1omatieally
selec1
ed
by che
playtr
unless
you is.sue
a
Stan-unit command,
H
described in Section
7
•
'SCSI
oper11ion".
The
player
is
in the
slave
mode.
whereby ii
e11.ec111u lhe~11nm.mhreceived
from lhe
«>mputer.
and
sends back
confinnalory
responsn.
An
F-code
con:.im of
one
or
more
8-bh bytes.
ooded in ASCII,
tennin.1
ned by
a
carriage
re1u111. These
codes
provide
inte
ractive
conuolol1hcplayerfortheuser.
"Ill~
it
only necessary
if you have selected
SCSI operalion and
then
wa
n
I
lo
switch to RS232-C operation.
Thc trans,nis.sion protocol for
RS232-C
mode
sckdion
is
described
below.
Note
1ha1 carriage returns should no1 be
sen1.
ACK
ref
en
10
a
Positive
acknowledgement
·A'
and
NACK
lo
a
Ne111tive
acknowled&emc:nt'N'.
I. The muter
sends
two
spaces.
2.
The
master
awaits
A
CK
from
lhe
player. If
1h.S
tS
/lOl
received
wlthin200ms,,etry.
3.
Thc
fflllSter
sends
the
mode
select
byte for
F
-code
communic-ation,
whtehisF.
4
.
Thc
master
awaits
ACK
from
the
playe
r. If
!his
ti
not received
wilhin
200
ms,
retry
mode
selection.
See Section
S
- "F<ode programming'.
SCSI
OPERATION
SCSI operation
provides
communication bc1w«n
the
pJaye
r
and
the
hOil
oomputer,
allowing
the
VP415
to
be used as an
LY-ROM
memory
device.
Bo
th data
mrieva\
from
the
disc, a
nd
conuol
of
the
player
are
possibte.
(h
is
also
possible 10
u.se
F<Odes
10
conuol
the
player
via
SCSI.)
.............
The
SCSI
mode
is selected
by
issuing
a
Stan
,
unil
command to
the
player. Sec Section 7
•
'SCSI
operation'.
19
Advertisement
