Re: DVORAK keyboarding on a //e--more info and more help, please

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

David Empson replied:

>Obsbedia2 <obsbedia2@aol.com> wrote:
>
>> I picked up a Canadian Platinum Apple //e that has the keyboarding switch
>> to switch from English to French keyboard layouts.  The switch does indeed
>> connect to J19 on the motherboard, the other two-pronged male connector
>> that looks like the speaker connector.
>> 
>> 1.  Could the Keyboard ROM from a //c or Laser128 be used to provide the
>> QWERTY and DVORAK keyboards?
>> 2.  What about the Video ROM?
>
>The reference manuals don't have circuit diagrams for the international
>models, so I can't be 100% certain, but I expect that the IIc video and
>keyboard ROMs would work in an international IIe.

The circuitry to support this switch is almost certainly trivial.  I expect
that it simply pulls to +5v the high-order address pin on the chargen and
keyboard ROMs, which are 2x the size of the "stock" ROMs.  The
pin is no doubt pulled down to ground through a 4.7K resistor, or so.
Of course, the sense of this pin could be the other way around, but
the way I describe would leave the current ROM images in the first
half of the new ROMs.

-michael

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