14
Please note:
The <DS> command is just a special case of the <DG> command but because of its fixed size is executed
much more quickly.
Graphics can be uploaded to a hidden frame using the <AF> command to select the destination, and the <VF>
command to make it visible when complete.
<DF
n
> Download Font command
The display has the capacity of storing four user defined characters for each font size. These “Soft Characters”
can then be written onto the screen by using the <WS
n
> command. They may also be underlined and flashed
using attributes, as any other character
After the <DFn> command is issued, the display expects a binary download of the soft character. The required
image size depends on the currently active font
Font:
F1
Image Size (v x h): 8 x 6 pixels
F2
16 x 10 pixels
F3
24 x 15 pixels
F4
32 x 19 pixels
F5
48 x 29 pixels.
The image must be exactly as defined above otherwise an error response is returned.
Nothing is drawn to the screen during this command
Uploads
The protocol is also extended to give the facility of obtaining a screen dump from the display. The main use for this is
in the preparation of instruction manuals, but it could also be used in a debugging role.
<UE> Upload Enable command
Because a graphic upload generates a significant amount of data, there must be safeguards in place to ensure
that the data is really required. The <US> Upload Screen command will therefore not respond unless it is
immediately preceded with the <UE> Upload Enable command.
<US> Upload Screen command
The command <US> is issued with any additional bytes (checksum, CRC etc) as required by the current
operational mode. The command is acknowledged if correctly received.
After a short delay of 500ms, a 1086 byte block of data is sent to the host.
(This delay is introduced to allow the host to set itself up for data reception).
A command acknowledge then follows with the check bytes as per the current operational mode. The check
bytes include the data block bytes and the acknowledge, but not the check bytes themselves.
The 1086 byte data block, once saved to file, is a graphics image of the screen in 2-colour Windows .BMP
format