Re: Hopefully last dumb newbie question.

[CUTjefbla@bconnex.net (Jeff Blakeney)]

On Thu, 04 Jun 1998 13:43:07 -0500, Slick <Slick_RCBD@hotmail.com>
wrote:

>Now the question. What exactly does the Alternate Display Mode DA do? I
>think it has something to do with the secondary text screen (Address
>$800-C00 on earlier models), but am not sure. None of the books at my
>library have anything about it. I do know about the shadowing to banks
>$e0 and $e1, and have looked at assembly language programming on the
>IIGS. I just never had the money to buy ORCA or APW. I've used the Hyper
>C (ProDOS 8, and free) assembler to write programs.

If I remember correctly, text page 2 doesn't get shadowed or the
softswitch for changing to text page 2 doesn't work or something like
that.  The Alternate Display CDA allows you to enable or disable
another shadowing routine, which is slower than the hardware
shadowing, but allows certain older 8 bit programs to use text page 2
so that they will work correctly.

If an 8 bit program crashes or doesn't run correctly, try enabling the
Alternate Display mode and try it again.  It just might work.

=== I've had enough SPAM.  Cut the obvious from my address to email me. ===
         Jeff Blakeney - Dean of the Apple II University on Delphi