Fairlight CVI, Руководство пользователя

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R S
2 3 2 C PO RT CO NTRO L
Data transfer comma n d s
The second type of command initia tes the transfer of a block o f
data to o r from the CVI. The parameters define the size and
loca tion of the da ta block.
When the command indicates that data is to be sent
to
the CVI,
the cha racters received immediately after the command are
interpreted as data. These data load modes are terminated when
the CVI has received the required number of characters, or when
a n
@
cha racter is received. The CVI gives a short beep when the
full requested block of data has been received or transmi tted.
In commands where data transfer is requested, each byte of
data is transmitted as two ASCII hexadecimal characters
(0 .. 9,A .. F). For example, a byte with decima l value
6 1
will be
transmitted as two ASCII characters "3D" (3x I 6+ 1 3), decimal
16
as
ASCII " 1 0", decimal
255
as ASCII "FF", and so on. The data
forma t is the same for loading data to or from the CVI.
When a command requests that data be sent from the CVI,
transmission of that data will begin
immediately
after the CVI
receives the last character of the command. If the computer
requires time to prepare to receive the data from the CVI then it
should hold the CTS handshake input to the CVI low until it is
ready to receive. The computer may lose some data if this control
line is not set. See the section on
Programming Your Compu ter
for more details.
Save Se
qu
e
n
c
er
Command: SS
This instructs the CVI to transmit the data of the current
Sequence. The Sequencer data block is 3000 bytes long, resulting
in 6000 transmitted ASCII characters. If the recorded Sequence is
short, then much of this data will be irrelevant. The recorded
Sequence always ends with a
zero
byte (two ASCII "0" characters),
and hence the receiving computer can detect the end of the
relevant Sequence data and ignore the remainder o f the block.
However, there is Colour Crawl and PAN initialisation data a t the
end o f the Sequencer data block which, aithough not essential to
Sequencer opera tion, is often useful. It is therefore left to the
user to decide whether the entire Sequencer data block or only the
recorded Sequence section is stored in the external computer.
Load Sequencer
Command: L S
The CVI will receive characters as Sequencer data. The data
(two ASCII characters per byte) will be wri tten to the Sequencer
data a rea, where they are interpreted as Sequencer instructions.
If unrecognisable commands a re received they appear as blank
lines in the SEQUENCER EDIT menu and are ignored. The CVI
will remain in the
Load Sequencer mode u n til 6000 characters
have been received or a n
@
character is received, initiating a new
command.
command.
SOFTWARE UPDATE
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