Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!usc!apple!uokmax!mhhaines
From: mhhaines@uokmax.uucp (Mark Howard Haines)
Newsgroups: comp.sys.apple2
Subject: Help (technical)
Summary: Help needed on I/O routines and mouse characters
Keywords: hardware mouse video
Message-ID: <1990May25.155413.5365@uokmax.uucp>
Date: 25 May 90 15:54:13 GMT
Distribution: comp.sys.apple2
Organization: Engineering Computer Network, University of Oklahoma, Norman, OK
Lines: 50

I have have several very technical questions that I hope someone can help me
with. I don't have access to Compuserve, so if someone doesn't know the
answers to these questions, but would forward them to Compuserve, I would be
most thankful.
   First let me describe exactly what I'm doing. I am creating a character set
for an apple //e that will include the german characters (7 additional). I
have already found how to burn the necessary ROM. Now I would like to make
my own I/O routines so that the user need only execute a machine language
routine and have special key presses access my character set.
   I have already made some progress, but I have several questions concerning
the hardware and software alike. So here goes:

1) I would like to place the new characters in ROM so that they replace the
   mouse characters. I know where in the video ROM the mouse characters are,
   but I can't get the computer to display them. I've tried poking numbers
   directly to the video RAM, so it has to be a soft switch. Anyone know where
   in memory the soft switch is wired?

2) I have and old reference manual that has an assembly listing of the old
   apple ][+ autostart ROMs. Does anyone know a book or any source where I
   can get a hold of a listing of the revisions for he //e. I would also
   like technical descriptions and schematics of the //e.

3) I have already tried replacing the keyboard reading and screen writing
   routines by altering the soft pointers in the zero page. It works okay
   except I have some problems with PRODOS and the cursor. PRODOS will
   reset a portion of the keyboard read soft vector every time it calls its
   character out routine. This is the only reason right now that I replace
   the character out soft vector with my own routine. Does anyone know of
   a good technical reference on PRODOS which gets down to the actual code
   listings?

4) When I replace the standard PRODOS output routine with the vector that
   the 80 column card sets up when PRODOS is not in memory, something funny
   happens. The cursor changes and freezes in place. This leads me to believe
   that the cursor on the 80 column card is controled separately. Am I correct
   in this assumtion? If so, how do I control the cursor?

Thanks in advance for all help. Like I said before anyone who wants to
forward this to Compuserve, please feel free. Or if you already know the
answers, please reply either in this news group or email to me at:

mhhaines@uokmax.ecn.uoknor.edu

I appoligize to the technical gurus out there for this. I use to be heavily
into th apple // series years ago and am now getting back into them. If I
hadn't left for so long, I would probably know much of what I have asked and
would probably have a library of books containing the references I have
mentioned. As it is, I have no idea right now where to find this information
so I am here wasting band width on the net.