Path: utzoo!censor!geac!torsqnt!news-server.csri.toronto.edu!rutgers!usc!jarthur!nntp-server.caltech.edu!toddpw From: toddpw@nntp-server.caltech.edu (Todd P. Whitesel) Newsgroups: comp.sys.apple2 Subject: Re: Stellar 7 re-release Message-ID: <1991Jan3.065643.24082@nntp-server.caltech.edu> Date: 3 Jan 91 06:56:43 GMT References: <60237@microsoft.UUCP> Organization: California Institute of Technology, Pasadena Lines: 27 brianw@microsoft.UUCP (Brian WILLOUGHBY) writes: >Multiple palettes are enabled by setting an interrupt bit for individual >scan lines. This interrupt does, in fact, take CPU time .... Moving from >320X200 with 16 colors to 320X200 with 256 colors takes CPU time. Not true. One of the unique features of the GS is real multiple palettes in hardware. There are 16 palettes, and each scan line can independently set the following attributes: 1 bit 640/320 mode 1 bit scan line interrupt 1 bit fill mode (only activates in 320 though) 1 bit (reserved for future expansion) 4 bits palette number (0..15) It is not that hard to write a program which will display all 256 colors and then return you to basic, without using any interrupts at all. I did in fact write one to view 256 color GIF palettes. Expect to see a similar function in an upcoming GIF decoder (yes, Unknown, I AM working on it). also, 3200 pictures cannot use scan line interrupts on every line. there isn't enough time once you count the interrupt manager overhead. you can use a few (I believe dreamgraphix's 3200-sluggish edit mode does that) but not all of them at once. Todd Whitesel toddpw @ tybalt.caltech.edu