Re: //e Keyboard problems

[mjmahon@aol.com (Michael J. Mahon)]

Jon Co wrote:

>I have a sort of related question.  I seem to have a US IIe, as I
>don't have that switch.  I have been looking at my IIe technical
>reference manual and I see solder/cut pads X1 X2 and X3 plus a
>connector J19.  Comparing this to the IIc technical reference manual,
>X1 and X2 would convert your language to the alternate language in
>your keyboard and display rom.  X3 would connect the switch to
>annunciator 2 so that it can be softswitch controlled.  J19 would be
>the exact equivalent of the IIc keyboard switch.  There's a part X3
>and a resistor that is enclosed by a dotted line, which i presume
>means it's not available in all revisions of the IIe board.  Well, I
>got a bit adventurous and seeing it won't cause any harm, I installed
>a jumper on my J19 and powered up the IIe.  Voila, the keyboard layout
>is now Dvorak, which is exactly what I wanted.  Pressing ctrl-G
>(ctrl-u on a qwerty labeled keyboard) rings the bell.  So I
>reassembled the IIe (put everything back on top of it) and turned it
>on.  Hehe, bad news.  no video.  I guess the keyboard ROM contained an
>alternate layout (Dvorak) but the Video ROM contained no alternate
>language...  Well, I didn't want to modify my main board, so I guess
>the only way to achieve what I want would be to get a 24 pin IC socket
>and bend out pin 12, and jump this one to ground.  Has anyone ever
>performed such a mod?

Selecting the alternate character set for the keyboard could be (is?)
completely independent of the character mapping for the video.

Dvorak just gives you an alternate way of getting the _same_ ASCII
characters into memory, so the _unmodified_ video should work
perfectly.

Either something unfortunate happened in the process to the video
circuits, or there is an unwanted connection of the keyboard encoder
ROM alternate address line to the video ROM, as well.  In that case,
cutting the appropriate trace should put things right.

-michael

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