ACT apricot - Page 280

CONTROL DEVICE
c. MicroScreen Driver
This option allows the programmer to bypass the normal
method of accessing the MicroScreen, and send characters
to the driver directly.
COM = 0:
DEV-51
COM - Either 0 or 1
DAT- From 0 to 255
DAT is ignored and RET will either contain 0, which
means that the MicroScreen is ready to receive characters,
(ie.
is online and working,) or-l which means that the
MicroScreen is in some way out of action.
COM = 1:
The character held in DA T is printed to the MicroScreen.
As
DAT is two bytes long, the character to be printed is held
in the low-byte. All the MicroScreen-specific escape
sequences can be used as normal.
Programming Example:
10 REM -- Program to write ACT on the MicroScreen --
20 DEF SEG=&H60 'Set default segment .
30 10=0 '10 indexes start of the Device I/O routine in memory
40 DEV%=51 'Select the device number to be the MicroScreen
50 COM%=l 'Command is 1, so we want to OUTPUT
60 RET%=O 'Dummy variable to hold Returned status
70 ' Send an A
80 DAT%=ASC("A") 'Set up data in DAT%
90 CALL IO(DEV%,COM%,DAT%,RET%) 'Call I/O routine to print character
100 ' Send a C
110 DAT%=ASC("C") 'Set up data in DAT% again
120 CALL I~(DEV%,COM%,DAT%,RET%) 'Call to I/O
130 ' Send a T
140 DAT%=ASC("T") 'Set up a liT" in DAT%
150 CALL IO(DEV%,COM%,DAT%,RET%) 'Call to I/O
160 DEF SEG:END 'End program