🚀 go-pugleaf

In article <851017-140850-1769@Xerox> Denber.wbst@XEROX.ARPA writes:
>...
>Adapting it for the 400 requires removing the 2 ICs on the board and
>soldering jumpers from the (now) empty holes to the keyboard socket
>in the 400.  One can figure out how to do this by reverse engineering
>...
>I went out and bought one of these keyboards (they look quite nice, and
>only $4.95!), but I don't have a TR Manual.  Does anyone have the
>information I need to make the connections?  Thanks.
>
>			- Michel

I too bought one, and promptly set about in search of my Dec '82 Creative
Computing, from which the following matrix is derived.  Note that this
is the original 400 keyboard circuits; I haven't finished tracing the
1200 keyboard yet to figure which pins go where.

wire #          1   2   3   4   5   6   7   8
------+----------------------------------------
    9 |        brk             ctl         both shiftkeys in parallel
   10 |         7   6   U   Y           N
   11 |                         J   H  spc
   12 |         8   5   I   T   K   G   M   B
   13 |         9   4   O   R   L   F   ,   V
   14 |         0   3   P   E   ;   D   .   C
   15 |         <   2   -   W   +   S   /   X
   16 |         >   1   =   Q   *   A  atr  Z
   17 |        bs  esc ret tab     cap

also, there is another set for the system keys

             18   19   20   21
   22      reset opt selec start

The article implies that these numbers refer to those of the wiring trunk
at the 400's membrane end.  I haven't figured out yet the values for the
extra pf keys, but it's a pretty good bet that they sit in the blanks for
rows 10 and 11.

-dave

-- 
-------------------------------------------------------------------------------
David Hsu						Across the net...
USnail: Communications & Signal Processing Laboratory	hsu @ eneevax.umd.edu
	Department of Electrical Engineering		hsu @ sphinx.ee.umd.edu
	University of Maryland				hsu @ mustafa.ee.umd.edu
	College Park, MD 20742				hsu @ umd2.arpa
BITnet: CF522 @ UMDD					hsu @ mit-prep.arpa

"You see?  You SEE???"

Well, I sat up and figured out the pin correspondences so you wouldn't have
to.  It seems Atari saved space (and wire) by moving those chips to the
keyboard, and so now, here is are the translations from the new wiring
to the old.  Old pin numbers refer to my previous posting.

         new pin #      old posting pin #
 IC #1      14              1
             1              2
             2              3
            15              4
             4              5
            13              6
            12              7
             5              8

ribbon pin  #1              9

IC #2        1             10
             2             11
            15             12
             4             13
             5             14
            14             15
            13             16
            12             17

ribbon pins 10             18   reset
            11             19   option
            12             20   select
            13             21   start
            14             22   (common to above)

I believe the matrix is correct, since I've tried at least two intersections
for each wire number.  Beset by a flakey meter, it took me nearly 20 minutes
to confirm my suspicion that old pin 9 was connected to ribbon pin 1.
BTW, ic#1 refers to the one on the left, between the m and comma keys, and
just in case somebody doesn't have the red stripe, ribbon numbers are numbered
from the spacebar side to the edge.

Get those 400's doing something. NOW!

-dave


-- 
-------------------------------------------------------------------------------
David Hsu						Across the net...
USnail: Communications & Signal Processing Laboratory	hsu @ eneevax.umd.edu
	Dept of Electr Engr, Univ Md			hsu @ mit-prep.arpa
	College Park, MD 20742				hsu @ umd2.arpa
UUCP:	{seismo,allegra}!umcp-cs!eneevax!hsu		BITnet: CF522 @ UMDD

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