Measurement Computing Personal488 rev.3.0 For DOS & Windows 3.Xi - Manual (Page 311)

15A. Driver488/DRV Commands III. COMMAND REFERENCES - 15. Command References
III-296 Personal488 User’s Manual, Rev. 3.0
•
1 : A response of 1 indicates that Driver488 has a response ready to be read by the user’s program.
The program must read the response before sending a new command (except IOCTL “BREAK” ) or
a SEQUENCE - DATA HAS NOT BEEN READ error occurs.
•
2 : A response of 2 indicates that Driver488 is waiting for data to OUTPUT to the I/O adapter. The
user’s program must send the appropriate data with terminators as needed to Driver488 with
PRINT statements (or their equivalent in other languages). Attempting to read from Driver488
while it is waiting for data, causes a SEQUENCE - NO DATA AVAILABLE error.
•
3 : A response of 3 indicates that Driver488 is waiting for the completion of a command. This is
similar to a response of 2 except that Driver488 is waiting for a command rather than for data to
OUTPUT .
The IOCTL$ command has two primary uses: In the Keyboard Controller Program it allows the
program to know when Driver488 has data available to read, and in BASIC Interrupt Service Routines
it prevents interrupts from being serviced while Driver488 is busy finishing a command.
Notice that IOCTL$ suppresses light pen interrupt emulation, so that the next time light pen status is
requested, it responds with a “no interrupt” status. Normal light pen interrupt emulation is then
restored. This is required to allow the BASIC
ON PEN function to operate normally. The IOCTL$
command can be accomplished in other languages by using MS-DOS function calls.
KEEP DEVICE
SYNTAX KEEP DEVICE name
name is the name of an external device.
RESPONSE None
MODE Any
BUS STATES None
SEE ALSO MAKE DEVICE, REMOVE DEVICE
EXAMPLES PRINT#1, “KEEP DEVICE SCOPE”
The KEEP DEVICE command makes the specified Driver488 device permanent. Permanent Driver488
devices are not removed when Driver488 is closed. Driver488 devices are created by MAKE DEVICE
and are initially temporary. Unless KEEP DEVICE is used, all temporary Driver488 devices are
forgotten when Driver488 is closed. The only way to remove the device once it has been made
permanent by the
KEEP DEVICE command, is to use the REMOVE DEVICE command.
KEEP DOS NAME
SYNTAX KEEP DOS NAME dosname
dosname is the name of the Driver488 DOS device.
RESPONSE None
MODE Any
BUS STATES None
SEE ALSO MAKE DOS NAME, REMOVE DOS NAME, KEEP DEVICE
EXAMPLES PRINT#1, “KEEP DOS NAME PLOTTER”
The KEEP DOS NAME command makes the specified Driver488 DOS device permanent. Permanent
Driver488 DOS devices are not removed when Driver488 is closed. Driver488 DOS devices are
created by
MAKE DOS NAME and are initially temporary. Unless KEEP DOS NAME is used, all
temporary Driver488 DOS devices are forgotten when Driver488 is closed. The only way to remove
the DOS device once it has been made permanent by the
KEEP DOS NAME command, is to use the
REMOVE DOS NAME command.
The Driver488 DOS device is attached to a Driver488 device that was specified when the Driver488
DOS device was created by
MAKE DOS NAME . If that Driver488 device is not permanent, then
KEEP DOS NAME makes it permanent, and then makes the Driver488 DOS device permanent.