RWMIRA01@ULKYVX.BITNET (Rob Miracle) (04/19/88)
I have a question. The PS/2's have been out for over a year now and considering the fact that no other IBM's have been available, why is there so little soft- ware for MODE 19 (13h). I have seen very little public domain software and just about the same amount of commerical software. Borland and Lotus only support the 640X480 1 color mode. I have seen one game out that supports it and CompuServe has a GIF decoder for 256 color mode. But that is about it. It is easy to write software for. The video ram is at segment A000h and each pixel is mapped to one byte where its value is the color of the pixel. I am working on a library of routines but I don't have a lot of free time to get any thing nice written. Has anyone heard why there is nomore software out for the 256 color mode or am I just clueless?
mcdonald@uxe.cso.uiuc.edu (04/19/88)
Why isn't there software for the PS/2 mode 19? Easy: it's low res. I can't think of any significant use for 200x320! It's a typical case of IBM producing a useless "feature". There is enough memory on a VGA for a 400X640X256color mode. Why isn't it there?
lau@sdics.ucsd.EDU (Stephen Lau) (04/24/88)
In article <45900123@uxe.cso.uiuc.edu>, mcdonald@uxe.cso.uiuc.edu writes: > > Why isn't there software for the PS/2 mode 19? Easy: it's low res. > I can't think of any significant use for 200x320! It's a typical case ... It may be low-res, but the number of colors available more than makes up for the difference. By blending many of the colors the appearance of a higher resolution can be generated. If you're looking for a good VGA program and MCGA program try out Deluxe Paint II by Electronic Arts. It blows Microsoft's paintbrush out of the water. Steve Lau | lau@sdics.ucsd.edu University of Ca, Sandy Eggo | ucsd!sdcsvax!sdics!lau Institute of Cognitive Science
mcdonald@uxe.cso.uiuc.edu (04/25/88)
>In article <45900123@uxe.cso.uiuc.edu>, mcdonald@uxe.cso.uiuc.edu writes: >> >> Why isn't there software for the PS/2 mode 19? Easy: it's low res. >> I can't think of any significant use for 200x320! It's a typical case ... > It may be low-res, but the number of colors available more than makes >up for the difference. By blending many of the colors the appearance of >a higher resolution can be generated. If you're looking for a good VGA program >and MCGA program try out Deluxe Paint II by Electronic Arts. It blows >Microsoft's paintbrush out of the water. >Steve Lau | lau@sdics.ucsd.edu >University of Ca, Sandy Eggo | ucsd!sdcsvax!sdics!lau >Institute of Cognitive Science / Steve, I don't see your point. I certainly see how I can take a high res 16 color display and get the impression of a larger palette by dithering, but I don't see how low res can be fixed. How would you simulate 80 column text on a 320 pixel wide display? Your statement isn't logical. Doug McDonald
sam@ncsuvx.ncsu.edu (Samuel A. Moore) (04/26/88)
In article <45900124@uxe.cso.uiuc.edu> mcdonald@uxe.cso.uiuc.edu writes: > >>In article <45900123@uxe.cso.uiuc.edu>, mcdonald@uxe.cso.uiuc.edu writes: >>> >>> Why isn't there software for the PS/2 mode 19? Easy: it's low res. >>> I can't think of any significant use for 200x320! It's a typical case Mode 19 is not insignificant. It is great for displaying digitized images. I have seen Amiga IFF files displayed in mode 19 and they look marvelous. More resolution would be great - even better. > >Steve, I don't see your point. I certainly see how I can take a high res >16 color display and get the impression of a larger palette by dithering, >but I don't see how low res can be fixed. How would you simulate 80 >column text on a 320 pixel wide display? Your statement isn't logical. > >Doug McDonald Doug, why not use another mode for 80 column text? Aren't there enough already? To appreciate mode 19 you must use it how it was meant to be used. Get a real-world image, something that doesn't have sharp borders on color changes, something that has a gradual blending of colors. Display it in EGA or VGA high res modes. Then display it in mode 19. Then appreciate mode 19. -- Sam Moore ||\\ || //==\\ //==\\ || || NCSU Computing Center || \\ || || ||==\\ || || Raleigh, NC || \\|| || || || || sam@ncsuvx.ncsu.edu || \\ \\==// \\==|| \\==//
lau@sdics.ucsd.EDU (Stephen Lau) (04/27/88)
In article <45900124@uxe.cso.uiuc.edu>, mcdonald@uxe.cso.uiuc.edu writes: > > >In article <45900123@uxe.cso.uiuc.edu>, mcdonald@uxe.cso.uiuc.edu writes: > >> > >> Why isn't there software for the PS/2 mode 19? Easy: it's low res. > >> I can't think of any significant use for 200x320! It's a typical case > > ... > > / > Steve, I don't see your point. I certainly see how I can take a high res > 16 color display and get the impression of a larger palette by dithering, > but I don't see how low res can be fixed. How would you simulate 80 > column text on a 320 pixel wide display? Your statement isn't logical. > > Doug McDonald "Logic is a wreath of pretty flowers that smell bad." Yes it would be impossible to generate crips text on such a display, but I think you're missing the point. The MCGA low-res was meant for crisp graphics not text. When using the low-res, you're not restricted to simply dithering with 16 colors. I recommend taking a look at some of the digitzed color pictures for MCGA which are floating around. Being able to generate text on MCGA would be nice, but you already have the VGA mode for it. Stephen Lau University of California, Sandy Eggo | lau@sdics.ucsd.edu Institute of Cognitive Science | ucsd!sdics!lau
mcdonald@uxe.cso.uiuc.edu (04/27/88)
>"Logic is a wreath of pretty flowers that smell bad." >Yes it would be impossible to generate crips text on such a display, >but I think you're missing the point. The MCGA low-res was meant for crisp >graphics not text. When using the low-res, you're not restricted to simply >dithering with 16 colors. I recommend taking a look at some of the digitzed >color pictures for MCGA which are floating around. Being able to generate text >on MCGA would be nice, but you already have the VGA mode for it. I have looked at many digitized images displayed in mode 19. When looking at them from a normal distance, say 15 or 20 inches, they look awful. All those little square pixels and all those jaggies look really bad. My complaint is that IBM put enough memory on the VGA to get 256 colors AND 400x640 resolution! This isn't going to be a problem with most add-in VGA cards, which probably will do 400x640/256, just with the ones that come with PS/2's. As an aside, have you looked at digitized pictures at 1024x1280x2^24? THAT looks nice! What I really like is the resolution I get with my camera, which is 5000x6250x(about 2^30) (okay, its 4inchx5inch Ektachrome). Doug McDonald
dmt@mtunb.ATT.COM (Dave Tutelman) (04/29/88)
I originally mailed this, but it bounced. However, the posting may not be entirely inappropriate... Steve Lau wrote: >> It may be low-res, but the number of colors available more than makes >>up for the difference. By blending many of the colors the appearance of >>a higher resolution can be generated. In article <45900124@uxe.cso.uiuc.edu> Doug McDonald responded: > >Steve, I don't see your point. I certainly see how I can take a high res >16 color display and get the impression of a larger palette by dithering, >but I don't see how low res can be fixed. How would you simulate 80 >column text on a 320 pixel wide display? Your statement isn't logical. Actually, logical or not, it has a certain truth. Doug talks about using SPACIAL dithering to make up for coarse COLOR quantization. Think about the converse, using COLOR dithering to make up for coarse SPACIAL quantization. What this CAN do is eliminate the "jaggies" from sloped edges on the screen, by modulating ("dithering") the color of each coarse pixel to weight each color by the amount the edge protrudes into the coarse pixel. What it CAN'T do, as Doug correctly points out, is 80-column text. So why use it at all? To give the APPEARANCE of high resolution in a picture that: - has low detail, so you don't need the REAL spacial resolution, but can afford to simulate it with color modulation ("dithering"). - requires smooth color transitions (shading), thus requiring more colors than the video RAM could support at high res. Either color dither or spacial dither would suit such images when viewed at a distance, and either technique falls apart when viewed close up. But the color dither seems to work better than spacial dither at middle distances. And it's especially good at continuous color transition across a "curved" surface (2D representation). Hope this helps. +---------------------------------------------------------------+ | Dave Tutelman | | Physical - AT&T - Lincroft, NJ | | Logical - ...ihnp4!mtuxo!mtunb!dmt | | Audible - (201) 576 2442 | +---------------------------------------------------------------+