On 4/10/04 5:36 PM, in article BC9DE10D.9D87%mpender@hotmail.com, "M. Pender" wrote: >> : - removal of the QHR graphics >> >> *WHAT* QHR? > > Quad-High resolution graphics. IIRC it was like DHR, but with twice as many > pixels across the horizontal dimension. Of course, since none of the Apple > software of the time used the mode, one might well question why the folks at > Laser bothered. I was wrong; DHR was the 560x192 graphics mode, QHR was the 560x384 graphics mode. Thus, it doubled the graphics across the vertical dimension, since it was a step-up from DHR graphics which already doubled the horizontal resolution. - Mike As I have experimented with this alternate video mode, I can attest that it displayed the hires/Dhires page1 on top and page2 on the bottom. It is more like an over/under mode that allows you to see both hires or Dhires screens at once. It was kind of interesting to invoke the video mode and then play something like karateka that alternated page1 and page2 to do animation. It was even interesting to watch a game disk load a title sceen on one half and you play the game on the other half. No programs reset the alternate video mode that I am aware of. Thankx, Ed Ed Eastman wrote: >As I have experimented with this alternate video mode, I can attest that >it displayed the hires/Dhires page1 on top and page2 on the bottom. It >is more like an over/under mode that allows you to see both hires or >Dhires screens at once. It was kind of interesting to invoke the video >mode and then play something like karateka that alternated page1 and >page2 to do animation. It was even interesting to watch a game disk >load a title sceen on one half and you play the game on the other half. So it is interlaced, with the odd half of screen 1 followed by the odd half of screen 2 in the first field, followed by the even half of screen 1 and the even half of screen 2? At least this approach makes it possible to leverage DHR drawing programs, if you allow for the 2:1 vertical compression. > No programs reset the alternate video mode that I am aware of. Not surprising, since it is a proprietary softswitch. -michael Check out amazing quality sound for 8-bit Apples on my Home page: http://members.aol.com/MJMahon/ Michael J. Mahon wrote: > So it is interlaced, with the odd half of screen 1 followed by the odd half of screen 2 in the first field, followed by the even half of screen 1 and the even half of screen 2? Interlaced no, squished to fit, yes. Perhaps my interpretation of interlaced is different than yours. I believe you are suggesting that the mode shuffles the lines together like a deck of cards or stacks them side by side for a right/left merging. It does not. It stacks page one and page two of either HGR or DHGR screens like two bricks, one on top of the other. Each graphic is squished so it all fits in the normal display area and effectively gives you twice the verticle resolution for any A2 standard video mode. (I'm uncertain which video modes it does NOT work in. I am not sure it works HR and DHR.) 40 column Text mode, page 1 or 2: 40h x 24v as text $400-7ff or $800-bff 80 column Text mode: 80h x 24v as text $400-7ff (main ram) & $400-7ff (aux Ram) (lores) Gr mode, page 1 or 2: 40h x 48v x 16c $400-7ff or $800-bff (lores) DGR mode: 80h x 48v x 16c $400-7ff (main ram) & $400-7ff (aux Ram) HGR mode, page 0 1 2 or 3: 280h x 192v x 5c $0-1fff, $2000-3fff, $4000-5fff, $6000-7fff DHR mode 1 or 2: 560h x 192v x 16c $2000-3fff (main ram) & $2000-3fff (aux ram) $4000-5fff (main ram) & $4000-5fff (aux ram) Laser128 only: QGR mode, single page consisting of page 1 and page 2 of normal mode: 280h x 384v or 560h x 384v Memory is page 1 _and_ page 2 of given mode, page one in the upper half of the screen, page two on the lower half. Thankx, Ed Ed Eastman replied: >Michael J. Mahon wrote: > > So it is interlaced, with the odd half of screen 1 followed by the >odd half of screen 2 in the first field, followed by the even half of >screen 1 and the even half of screen 2? > >Interlaced no, squished to fit, yes. Perhaps my interpretation of >interlaced is different than yours. I believe you are suggesting that >the mode shuffles the lines together like a deck of cards or stacks them >side by side for a right/left merging. It does not. It stacks page one >and page two of either HGR or DHGR screens like two bricks, one on top >of the other. Each graphic is squished so it all fits in the normal >display area and effectively gives you twice the verticle resolution for >any A2 standard video mode. (I'm uncertain which video modes it does >NOT work in. I am not sure it works HR and DHR.) Ed, since each hi-res page has 192 lines, and since the monitor you are using is only capable of approximately 60Hz vertical deflection and approximately 15kHz horizontal deflection, the only way to get more than 260 or so lines (including vertical blanking interval) is to interlace. By that, I mean that all the odd-numbered lines of both screens are displayed first (the first 192 active lines), then all the even- numbered lines of both pages are displayed between the odd lines of the first field. This will create an image of screen 1 over screen 2, each screen containing 192 active lines. This is the way that "ordinary" TV gets about 500 lines, and is the only way that a TV-standards display can do so. Laser chose a video order that is harder to achieve by modifying an Apple than simply displaying screen 2 interleaved with screen 1 (which is still an interlaced display, but with all of the first field being screen 1 in normal order, and all of the second field being screen 2 in normal order). The only advantage I can see to the choice Laser made is to allow ordinary graphics "paint" programs to be used to paint separately the top half and the bottom half of the QGR screen (allowing for the 2:1 vertical pixel compression). >40 column Text mode, page 1 or 2: 40h x 24v as text >$400-7ff or $800-bff > >80 column Text mode: 80h x 24v as text >$400-7ff (main ram) & $400-7ff (aux Ram) > >(lores) Gr mode, page 1 or 2: 40h x 48v x 16c >$400-7ff or $800-bff > >(lores) DGR mode: 80h x 48v x 16c >$400-7ff (main ram) & $400-7ff (aux Ram) > >HGR mode, page 0 1 2 or 3: 280h x 192v x 5c >$0-1fff, $2000-3fff, $4000-5fff, $6000-7fff > >DHR mode 1 or 2: 560h x 192v x 16c >$2000-3fff (main ram) & $2000-3fff (aux ram) >$4000-5fff (main ram) & $4000-5fff (aux ram) > >Laser128 only: >QGR mode, single page consisting of page 1 and page 2 of normal mode: >280h x 384v or 560h x 384v >Memory is page 1 _and_ page 2 of given mode, page one in the upper half >of the screen, page two on the lower half. The problem with _any_ extension of a popular platform is that it takes a long time--maybe never--before there are enough of them in the platform mix so that it makes any sense for a developer to invest in supporting the extension. The worst case scenario is that it gets to be barely critical mass, and has the effect of splitting the market for developers, so each part of the market gets only its "share" of developers. If the extension is critical and enabling, then new kinds of applications will be written, but only after critical mass is achieved. If the extension is only "more of the same", it rarely enables the development of really compelling apps, and that, in turn, limits the value of the extension. -michael Check out amazing quality sound for 8-bit Apples on my Home page: http://members.aol.com/MJMahon/