Re: //e Keyboard problems

[jon@i-manila.com (Jon Co)]

The alternate layout for keyboard and alternate language for video
display is wired together in both the IIe and the IIc.  In the IIc it
is connected to the "keyboard" switch and labeled "LANGSW" on the
schematic.  the IIe's is not labeled "ENVIID", which is grounded via a
1k ohm resistor and can be made high by shorting J19.  If my IIc's
chips was socketed and not soldered I might be willing to experiment
further and confirm my suspicions but I think all IIc's had soldered
chips.
While I was at it I also traced the other solder/cut pads and found
the following: X4 & X5 changes the input to one of the NOR gates
leading to phase 0 of the 65c02 from a line called "DMA" to
permanently grounded.  I wonder what this is for hmm?  X6 seems to be
the 1 wire shift-key modififcation (does this still short out the
system when the shift key was operated with the 2nd set of game
controllers?) X7 connects the "GR" line to a supposedly unused pin in
slot 7.
mjmahon@aol.com (Michael J. Mahon) wrote in message news:<20030216183400.29567.00001293@mb-mv.aol.com>...
> 
> 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
> 
> Check out amazing quality 8-bit Apple sound on my
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