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Re: Apple //e hardware question

On 5/22/2013 10:06 PM, mdj wrote:

On Thursday, 23 May 2013 11:59:24 UTC+10, Charlie  wrote:


The reason is, I'm going to add some Apple IIgs functions to my //e, and

I want them to be compatible with a IIgs.  So I want to use the same

locations as the IIgs does.  Specifically, I'm going to add Super HiRes

graphics and I want the status of the softswitch/registers to be

readable from //e programs.


Very cool! :-)



Thanks.


The Apple II Video Overlay Card does exactly this. ISTR it's documented in one of the Apple II technical notes. $2000-$9FFF of auxiliary memory holds the super hires display data, just as it does in bank $E1 on a IIgs.



I'll take a look at that tech note.


The penny should have dropped when you mentioned $C029, but I guess it's been a while ;-)
I mostly use the IIgs but noticed that Super HiRes would fit easily on a my //e (using the Carte Blanche card). I wonder if Apple was thinking of putting SHR on a //e at one time. 

Charlie