🚀 go-pugleaf

In article <4178@blake.acs.washington.edu> Dale Larson writes:
>I do not recommend replacing your A500 keyboard with an A2000 keyboard.

I don't share Dale's opinion. I certainly recommend replacing the keyboard.

This is an article that I wrote two months ago but never got
around to posting:
----------------------------------------------------------------------
Some time ago somebody asked if it was possible to connect an
A2000 keyboard to an A500. Well, it is, sort of...

Here's the story.

Ins and outs (from the TECHREF manual):
A2000
                           2          1 KCLK     Keyboard clock
      __ _____          5     4       2 KDAT     Keyboard data
     |  |     \____                   3 NC
---> |  |     |____    3       1      4 GND
     |__|_____/                       5 +5
                                      6 SHIELD
                           6


A500 - from left to right when facing the machine (bus side to floppy side)

   1 KDAT    Keyboard data
   2 KCLK    Keyboard clock
   3 RESET   Reset signal (Hard wired)
   4 +5
   5 KEY     Beats me
   6 GND
   7 STATW   Power LED
   8 INUSE   Floppy LED

Using this information I connected 2000 to 500; 1-2, 2-1, 4-6, 5-4.
When I switched on I got a stream of (not acrid smoke :-) quotes.
According to an earlier posting by George Robbins at CATS this meant
that KDAT and KCLK were swapped. I changed my connections to:
1-1, 2-2, 4-6, 5-4. This time, no smoke, no quotes. So, I try to type
something. Things look strange and after a couple of characters I
get no output. Since I use conman (and VT100s) I try a Ctrl-Q.
Ok, back in business. By now I can type almost anything, except "m",
"n" and cursor keys. After a while I realise that these keys have
some special meaning when used together with left and right amiga keys.
I press and release left amiga and right amiga and finally everything
works. So it seems like the A500 believes that the reset-keys are down.
By pressing and releasing them one at a time I tell the A500 that
they're up. The same thing happens if you try to reboot the A500 by
pressing ctrl-amiga-amiga. What happens is that the A500 registers
that the keys are pressed and then the keyboard resets itself leaving
the A500 believing that the reset-keys are still down. Question: How
does the A2000 detect a reset? Is there any HW involved? Is there a
difference in the ROMs between the A500 and the A2000?

Disclaimer:
I take no responsibility at all for any damage made to your Amiga.
Neither because of this fix or any other reason, such as earth quakes,
tornados etc.

Problems:
You can't do a 3-finger reset. It doesn't matter much to me since I
don't reboot often (twice a week maybe).

Questions:
Why did I have to swap KDAT and KCLK? Have I done anything wrong?
Would it be possible to connect both keyboards at the same time?
Would it be possible to connect a keyboard via the serial port?
Where can I find a specification of the data sent from the keyboard?
Comments? George? Dave?

Last recommendation:

     I would feel much safer if you wait for somebody who knows what
     he's talking to acknowledge this before you start mutilating
     your Amiga 500 (and your friend's A2000 ;-).
----------------------------------------------------------------

Have fun.

Mikael Karlsson, Lovsattersvagen 10, S-585 98  LINKOPING, SWEDEN
micke@slaka.UUCP, micke@slaka.sirius.se
{mcvax,munnari,seismo}!enea!liuida!slaka!micke
C86.M-KARLSSON@LINUS.liu.se