Asynchronous Serial Communications Programmer's Reference Manual (32022-90052)

246 Chapter9
Intrinsics Reference (cont)
FOPEN
configured for the port. The default value of recsize is
the configured record size (normally 40 halfwords for
terminals, 66 halfwords for printers).
device character array (optional)
A byte array in which you can specify a particular
device class or logical device number. On a terminal,
you must use this parameter if you intend to read and
write through a single file. (That is, if you intend to
FOPEN the device once, with read and write access,
you must use this parameter.) Note that all character
arrays must start on a halfword boundary.
This parameter optionally specifies environment files
for certain Hewlett-Packard laser printers
(;ENV=printenv).
formmsg character array (optional)
Passes a forms message that you can use for such
purposes as telling the System Operator what type of
paper to use in the line printer. This message will be
displayed on the console when the file is ready to print,
and processing will be delayed until the System
Operator verifies that the correct forms are in the
printer and responds accordingly. The message can also
be used for terminal files.
The message itself is a string of ASCII characters
terminated by a period. The maximum number of
characters allowed in the array is 49, including the
terminating period. Arrays with more than 49
characters are truncated. Note that all character arrays
must start on a halfword boundary.
This array also has significance when used for magnetic
tape files. See the MPE/iX Intrinsics Reference Manual
for more information on this usage.
userlabels 16-bit signed integer by value (optional)
Not meaningful for asynchronous devices. Applies to
disk files only.
blockfactor 16-bit signed integer by value (optional)
Not meaningful for asynchronous devices. Blocking
factor is always 1.
numbuffers 16-bit signed integer by value (optional)
The number of buffers, number of copies, and output
priority to be applied to the file, indicated by three bit
groupings.