From: Jim_Johnson@abcd.Houghton.MI.US (Jim Johnson)
Newsgroups: comp.sys.atari.8bit
Subject: Re: Function  Keys
Distribution: world
Date: 21 Jul 92 07:56:56 EST
Organization: Amiga BitSwap Central Dispatch

In a message dated Mon 20 Jul 92 16:07, Jeff Mcwilliams <jjmcwill@mtus5.bit
wrote:

 JM> Someone asked for me to post the 1200XL function key upgrade
 JM> modification for XL/XE computers, so here it is.

 JM> This is from Michigan Atari Magazine, October 1987.
 JM> By Charles Cherry, reprinted from ABACUS, August 1987.
[text edited]
 JM> I was reading a letter to the Editor of Current Notes (the newsletter
 JM> of the Washington, D.C. area users) from Roger Tolbet of Ozark,
 JM> Alabama.  It seems he grafted a 1200XL keyboard into an 800XL and
 JM> discovered the 800XL operating system supports the 1200XL function
 JM> keys!  "So what," I hear you say.  "No one ever wrote any software
 JM> for the function keys."  True.  But the function keys do some pretty
 JM> interesting things all by themselves.  Like controlling the cursor.
 JM> No more holding down the control key.  I immediately opened my
 JM> brother's 256KXL (formerly an 800XL), drilled four holes in it for
 JM> push buttons, and wired them in.

 JM> It works like a charm.  This is something I have to have.  Guess
 JM> what.  It works on my 320XE (formerly a 130XE) too.  Here's how to do
 JM> it.

 JM> Get four normally open push button momentary switches (Radio Shack
 JM> 275-1547  -- $2.69 for 4).  Decide where you want to put them.  I put
 JM> them in a diamond shape above the CONSOL keys of my brother's XL.  I
 JM> put them on the side of my XE.  Open up your computer and take off
 JM> the metal RF shield.  Install the buttons.  Find U24 and U25 on the
 JM> XL.  I don't know the chip numbers on the  XE, but they are easy to
 JM> find.  They are 16 pin chips and are near where the keyboard
 JM> connector attaches to the motherboard.  They should say 4051
 JM> somewhere on them.  Use the one closest to the front of the computer
 JM> as U25 and the one behind it as U24.  Wire the buttons as follows:

 JM>    Button  U24     U25
 JM>      Up     1       4
 JM>     Down    12      4
 JM>     Left    1       5
 JM>     Right   12      5

 JM> [I did this on a 600XL, and moved from pin 12 to pin 13 on U24 to
 JM> make it work... Jeff ]

 JM> (each button connects to both chips.  One contact connects the
 JM> indicated pin on one chip, the other contact connects to the
 JM> indicated pin on the other chip.)

 JM> This is a real easy project and the rewards are great.  I encourage
 JM> you to try it.

 JM> [ See either the 1200XL addendum to the Atari 400/800 Technical
 JM> Reference Notes, or the revised edition of Mapping Atari for details
 JM> on what the function keys do.  In Mapping the Atari, see the XL/XE
 JM> Appendix under memory location  96 and 97.

 Additional notes from Jim Johnson:
A couple things... First is that the keyboard decoder chips are sometimes
reversed on some motherboards - if you find the above connections don't
work, simply reverse the connections.

The suggestion for mounting the switches in a diamond shape is an excellent
one - it's what I did when I installed my 1200XL function keys on my 320XE
several years ago; it is much easier to remember which function key moves
the cursor in which direction.  Also, I would suggest that you NOT mount
the keys directly on the case.  I mounted them to a small square pill box
and used velcro to attach this box to the lower right corner of the case. A
small ribbon cable looped down through the case halves to the keyboard
decoder chips.  By doing this I could open up the case for repairs without
having wires connecting me to the case top.

By the way, Innovative Concepts in Warren Michigan sells a modification kit
for the Atari 10key pad and the deluxe version also includes the function
keys.  The kit guts the 10key pad and attaches it to the keyboard decoder
chips the same way as the function keys - the result is a 10key pad that
requires NO drivers and works with ALL software. In essence the keys are
simply wired in parallel. You wouldn't believe how much easier this is when
you have to do extensive numeric entry such as spreadsheets or DATA
statements.


-- Via DLG Pro v0.992

Jim Johnson-
*** Remember, they're only tools - Not a way of life! ***