jshaver@APG-5.ARPA.UUCP (05/13/87)
A form of double Hires is available to the ][ and // apples. There were 5 or 6 articles in Nibble several years ago and they have a disk with some of the software available on it . I have the disk, but I'm still having trouble with plain hires. John Don't Give me that artificial Stuff, I need the real intelligence.
ralphw@ius2.cs.cmu.edu (Ralph Hyre) (05/14/87)
In article <8705131249.aa16999@SMOKE.BRL.ARPA> jshaver@APG-5.ARPA (John Science Fiction & Resume Service Shaver) writes: >A form of double Hires is available to the ][ and // apples. There were >5 or 6 articles in Nibble several years ago and they have a disk with some >of the software available on it . I have the disk, but I'm still having >trouble with plain hires. I believe the standard trick (I read it in a Don Lancaster article on the Apple Luminance board in Popular Computing.) is flip between both Hires pages. Set up all bytes in page 0 with the high bit off, and all bytes in page 1 with the high bit on. Then you flip between pages during the vertical blanking interval, and you sort of get doubled resolution (but probably only effectively monochrome, since you have even stranger color interactions than with 'normal' hires.) To read the sync status, it helps to have the 'field sync' mod to the Apple (documented in another Lancaster book), although it is possible to 'read the floating bus' and get some idea where the vertical retrace is on some Apples. Similarly, has anyone been able to double vertical resolution by some other hack? It seems like you could alternate between the odd and even interlace fields by flipping pages every 60th of a second, but maybe the fact the Apple video is 'non-interlaced' will prevent this. (I assume that interlace is more a function of the monitor rather than the video source.) I sure wouldn't mind having a 560x484 display with some software work. -- - Ralph W. Hyre, Jr. Copyleft 1987 by Ralph W. Hyre, Jr. Internet: ralphw@ius2.cs.cmu.edu Phone:(412)268-{2847,3275} CMU-{BUGS,DARK} Amateur Packet Radio: N3FGW@W2XO, or c/o W3VC, CMU Radio Club, Pittsburgh, PA
hentosh@amethyst.bucknell.EDU (03/10/89)
Can anyone tell me if page flipping is possible with Double HiRes.
And if so, how to do it from assembly. Also if you know how to
setup the Super HiRes Screen, is it necessary to request it from the
memory manager? Any help would be appreciated.
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