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Path: ns-mx!uunet!olivea!mintaka!ogicse!orstcs!jacobs.CS.ORST.EDU!throoph From: throoph@jacobs.CS.ORST.EDU (Henry Throop) Newsgroups: comp.sys.apple2 Subject: Re: Increasing Graphics Resolution Message-ID: <throoph.674953378@jacobs.CS.ORST.EDU> Date: 22 May 91 23:02:58 GMT References: <91141.165437HDK@psuvm.psu.edu> <1991May22.095144.20649@lynx.CS.ORST.EDU> Sender: @lynx.CS.ORST.EDU Organization: Oregon State University, Computer Science Dept Lines: 38 Nntp-Posting-Host: jacobs.cs.orst.edu In article <91141.165437HDK@psuvm.psu.edu> HDK@psuvm.psu.edu (H. D. Knoble) writes: >We are running an Apple IIe, 128K, 80-Column Card, enhanced, either DOS 3.3 >with AppleSoft or ProDos. We are looking for specific concrete answers >with examples that run if this is practical. >1) Is there any way (even with PEEK/POKE) to get more resolution from a > 280 by 170 high resolution screen? Is there any mechanism to get more > colors? If all you need is monochrome, you can get 560x192 on a standard hires screen. This is because in an 8-bit byte on teh hires screen, seven bits are pixel on/off flags, and the high bit indicates which of two color sets to use for that byte. One color set (white1, green, purple) is shifted half a pixel to the left compared to the other set (white2, red, blue). If you have an x-position vaue between 0 and 559, divide the vaue by two, then choose the appropriate color based on x mod 4. This short routine wil do that - 10 x2 = int(x/4):x3 = x-4*x2 20 if x3 = 0 then hcolor= 2 30 if x3 = 1 then hcolor= 6 40 if x3 = 2 then hcolor= 1 50 if x3 = 3 then hcolor= 5 60 hplot int(x/2),y Note that this doesn't allow you unlimited placement of pixels - the 7 pixels in a byte must be either shifted right or left. Also, of course it's only monochrome and you have to view it on a mono monitor; otherwise, it will just look like a big mess. Henry -- -- Henry Throop throoph@jacobs.cs.orst.edu THROOP@GRIN1.BITNET