Re: Double-Width HiRes

[greg@apple2.com]

In article
<jonINTERNETrelayCHAT-1411991757170001@nn-157-22-181-165.napanet.net>,
jonrelay@napanet.net (Jon Bettencourt) wrote:

> I need a way to turn on Double-Width Hi-Res graphics and BLOAD a 16K file
> onto the screen. The first 8K of the file goes in page 1 of hi-res
> graphics in the main memory, the other 8K of the file goes in page 1 of
> hi-res graphics in the auxilary memory. Regular BLOADing results in the
> first 8K in page 1, and the remaining 8K in page 2. Or maybe a program to
> transfer page 2 of main memory hi-res to page 1 of auxilary memory hi-res
> would be easier.

ProDOS comes with a method to do the latter:

    BLOAD sixteen.k.file,A$2000
    BSAVE sixteen.k.file,A$4000,L$2000,S3,D2

Assuming of course you have no files currently stored in /RAM, the S3,D2
RAMdisk.  The memory allocation for /RAM is designed so that this works. 
There's an Apple Technote on the subject.

The task is only slightly more complex if the file was saved aux-mem
segment first.

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