INTERLISP Q

[CSD.FREEMAN at SU-SCORE]

I am writing a display representation language editor and for various
reasons have decided not to put the display package in the editor, like
the existence of terminal independent dpy packages, the capabilities of
altos, the advantages of local dpy for remote editing, etc., and want
to start a program running concurrently with INTERLISP. Since it is
to run while INTERLISP is running, SUBSYS isn't the right thing, but
it is close. To communicate between the two programs I'm going to use
pty's, thus (INFILE Pty#:) (OUTFILE Pty#:) seem to be just what I want.
I plan on using the following scheme to start the dpy program.
    1) Use (INFILP file) to verify/expand the file name
    2) Use (OPENFILE file INPUT NIL 36) to open the file
    3) Use (OPNJFN file) to get the jfn to pass to some ASSEMBLE code
	that will start the program running on a fork.
    4) The program will then sti the pty# to interlisp and it will
	use INFILE/OUTFILE as above.

My question is basically, what is wrong with the scheme, assuming that
I really do want ptys and a concurrent dpy program?  Should I avoid
ASSEMBLE as much as possible and use (JS ...) when possible?  What about
jsys errors?

The alto and other non-local versions will have the dpy package "above"
INTERLISP, so all this will be unused, but for now....

Thanks for your help,
andy
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