Jim Hall wrote: >> Ultimately, a virtual dot matrix printer should support "half dot" >> print head vertical movement too, so you can print at very high >> resolution. [..]
On Thu, Aug 13, 2026 at 10:13 AM Alain Mouette wrote: > > I've been trying to figure out a good method to do that on screen. > > Some Dot-matrix had a possibility (mine had) to advance the paper > by a half dot and pront overlapping dots... But I believe it will > hava a poor aspect on screen as dots really were intended to overlap > and it would me messy on screen I think I know of a way to do it if I'm writing to a PGM file. But it doesn't extend to DOS graphics. If it's PGM: Each "dot" actually takes up a 3x3 grid, where the center is basically black and you have a partial gray value for each of the 8 boxes around it. This is easy if you're doing it in PGM, because if "0" is black and "15" is pure white, then different values of "gray" are just division. Each "dot" 3x3 grid actually overlaps the previous "dot" 3x3 grid. Let's say one "dot" is this 3x3 grid, where "1" is the center and "o" are the 8 squares around it: ooo o1o ooo ..then the adjacent "dot" is another 3x3 grid that overlaps the last column of the previous "dot." Let's show the overlapping dots as "O": ooOoo o1O2o ooOoo ..and so on for other dots. If I'm just printing out two rows of two dots: ooOoo o1O2o OOOO o3O4o ooOoo HOWEVER, this is probably not possible in SVGA graphics, just based on resolution. If I assume a "page" is 510 "dots" wide (8.5 inches) and 660 "dots" long (11 inches), that's easy to do in SVGA (XRES 1024x768). I'll run out of room if I want to display a single page WITH THAT METHOD in portrait view in 1024x768. So I think the easiest way to do this is one "dot" per pixel, and square pixels. Then a page is 510x660 pixels, which easily fits on 1024x768. _______________________________________________ Freedos-devel mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/freedos-devel
