ACT apricot - Page 261

INTRODUCTION
The MicroScreen is treated by the BIOS as a serially-
accessed device.
Not only text output is supported, but the
LED's associated with the membrane keys can be switched
on and off. It accepts characters sent to it, some of which are
special
controls (such as clear screen, position cursor etc.)
The BIOS has an internal table of the Sirius-compatible
escape codes, which operate as an "interpreter" for the user,
so
no actual machine-level direct access to the MicroScreen
is required.
APPLICATIONS INTEREST
Within the BIOS and MS- DOS device table, the ASCII
string "MSCREEN" is used as a device name so that it can
be referenced when a file is opened, and subsequent output
to that file sent to the MicroScreen. Here is a programming
example:
10 OPEN "0",1,"MSCREEN"
20 PRINT#l, "This Is The MICROSCREEN!"
30 CLOSE 1
It will be noted that the output will not appear on the
MicroScreen until the file is CLOSEd. This is due to
MS-DOS, which saves all serial output of this kind until its
internal buffers are full, then it sends the data to the screen.
For
alternative ways of accessing the MicroScreen, refer to
the Device I/O - Control Device section. Table 1 is a list of
the escape codes that the MicroScreen recognises. If an
un-recognisable escape sequence (including ANSI) is
recieved,
the cursor position remains unchanged, and no
action is taken.