Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!uunet!microsoft!brianw From: brianw@microsoft.UUCP (Brian WILLOUGHBY) Newsgroups: comp.sys.apple2 Subject: Re: Stellar 7 re-release Message-ID: <60237@microsoft.UUCP> Date: 3 Jan 91 02:45:10 GMT References: Reply-To: brianw@microsoft.UUCP (Brian WILLOUGHBY) Organization: Microsoft Corp., Redmond WA Lines: 31 scottg@gnh-starport.cts.com (Scott Gentry) writes: >The standard resolution are: Any Apple II graphic mode, PLUS, Super Hi Res in >320x200 with 16 colors and 640x200 with 16 dithered colors (Four pure colors). >A variant that doesn't require special programing to display but requires >special programming to create is 320x200 with 256 colors (16 palettes), or >640x200 with 256 colors (16 palettes). People should really look at what can >be done with 16 properly used colors. I know I was stunned. I think that you are overlooking a detail in the design of the GS. Multiple palettes are enabled by setting an interrupt bit for individual scan lines. This interrupt does, in fact, take CPU time to handle, as all 16 color registers must be loaded for the new palette. Just because all of this is set up by the system and not by your own code does not mean that it is totally free. There is a CPU time price. Moving from 320X200 with 16 colors to 320X200 with 256 colors takes CPU time. Of course, I am just being nit-picky. There are other interrupts occurring in the system anyway, each of them eating valuable CPU time as well. You can't get away from the time loss completely, anyway. Also, 16 palette interrupts (for 256 colors) per screen is far less time consuming than 200 palette interrupts (for 3200 colors) per screen. With 60 screens per second, you are looking at only 960 interrupts per second for 256 colors instead of 12,000! for 3200 colors! Brian Willoughby UUCP: ...!{tikal, sun, uunet, elwood}!microsoft!brianw InterNet: microsoft!brianw@uunet.UU.NET or: microsoft!brianw@Sun.COM Bitnet brianw@microsoft.UUCP