tschak909 Posted November 12, 2022 Share Posted November 12, 2022 Is it possible to modify COLPF3 in mode 7, mid-scanline? I found myself exactly ONE COLOR short. -Thom Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 12, 2022 Author Share Posted November 12, 2022 am...guessing...not.... crap. Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 12, 2022 Author Share Posted November 12, 2022 oh well, code is here for anyone who wants it anyway: https://github.com/tschak909/apx-logo -Thom Quote Link to comment Share on other sites More sharing options...
FifthPlayer Posted November 13, 2022 Share Posted November 13, 2022 (edited) You could try setting the priority registers and overlapping the PM sprites in that rightmost vertical bar to get another color, (or for that matter in any of the other vertical bars) but it may not be the color you were hoping for. Looks like you were hoping for a very dark green, if the pics I'm finding online are your inspiration? Edited November 13, 2022 by FifthPlayer Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 13, 2022 Share Posted November 13, 2022 You can do that colour change. But the DMA load is different on the first scanline where the character codes are fetched so you'll need different delay on that one. For Mode 4/5 you can't do it on first scanline since they lose practically all the display cycles for alternating character/font fetches. But Mode 6/7 only needs half the bandwidth so there's free cycles in there. That said though you have refresh losses as well so the timing isn't straightforward. 1 Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 13, 2022 Author Share Posted November 13, 2022 3 minutes ago, Rybags said: You can do that colour change. But the DMA load is different on the first scanline where the character codes are fetched so you'll need different delay on that one. For Mode 4/5 you can't do it on first scanline since they lose practically all the display cycles for alternating character/font fetches. But Mode 6/7 only needs half the bandwidth so there's free cycles in there. That said though you have refresh losses as well so the timing isn't straightforward. uuuuuuuuuuuuuughhhhhhhhhhhhhhhhhhhhhhhh............. Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 13, 2022 Author Share Posted November 13, 2022 am currently thinking on it, looking at the antic dma analysis... Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 13, 2022 Author Share Posted November 13, 2022 I did try very hard to try and squeeze out enough time to make it possible: The top portion of the screen is blank, and immediately after mode 7 is done, a JVB happens. I also used double-line PM's. -Thom Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 13, 2022 Share Posted November 13, 2022 You'd probably find it easier to just use a single DLI then a loop for the overall display. Maybe do a single blank line with the DLI on it before the mode lines to give a bit of extra time. Character fetch lines will have a shorter delay needed than the other ones. Altirra Atari Hardware Manual also has reference pages describing DMA patterns for each graphics mode type. Quote Link to comment Share on other sites More sharing options...
glurk Posted November 13, 2022 Share Posted November 13, 2022 Yeah, you really want to use a DLI (for X number of scanlines) instead of an infinite loop. And what I would do is use PLAYER0 for both the leftmost and rightmost bars, and change it's horizontal position and color mid-scanline. Which absolutely works, you just have to have the timing right. So right after the WSYNC, set it's color and the leftmost position, then at the appropriate color clock, set it's rightmost position and color. Easier to do it this way than it is to try to hit an EXACT cycle to change the color, because of jitter, etc... My post here is related to this: 1 Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 13, 2022 Author Share Posted November 13, 2022 Getting closer. Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 13, 2022 Share Posted November 13, 2022 PMs would probably do the trick easily but IMO a programatic solution is much cooler. Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 13, 2022 Author Share Posted November 13, 2022 am currently using ALL The players, missiles, and playfield colors. Am using a DLI now to reposition player 0 (the dark blue bar) over to the other side. -Thom Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 13, 2022 Share Posted November 13, 2022 OK. Also note having PMG DMA active vs not will make timing different though you'd probably have it active all the time I guess. You could use GPRIOR = 00 and/or multicolour PM mode to gain more colours though the resultants are palette entries ORed together so not necessarily giving you what you need. I'm guessing you want something near to what they used on the manual covers which comes to a rainbow of about 28 different values. Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 13, 2022 Share Posted November 13, 2022 I wonder - what if you used Antic F (hires) then changed to GTIA mode for the rainbow part each scanline? Or you could even change to GTIA mode and back which gives the 4-colour mode though it mightn't be sufficient. Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 13, 2022 Author Share Posted November 13, 2022 The original graphic. Quote Link to comment Share on other sites More sharing options...
+MrFish Posted November 13, 2022 Share Posted November 13, 2022 28 minutes ago, Rybags said: I wonder - what if you used Antic F (hires) then changed to GTIA mode for the rainbow part each scanline? Antic F / GTIA was the first thing that came to my mind too; but putting the color bars at the bottom instead. Well, putting the color bars at the bottom would fix your mode 7 problem as well... Quote Link to comment Share on other sites More sharing options...
glurk Posted November 13, 2022 Share Posted November 13, 2022 What he's doing (APX Logo with 8 colored bars) is totally possible. But the GitHub code has an endless loop instead of a DLI... Please re-up code that has the DLI implemented, and I'll see if I can do it... Quote Link to comment Share on other sites More sharing options...
Rybags Posted November 13, 2022 Share Posted November 13, 2022 Unsure if this will work - how about Mode F then change to GTIA mode per line. Do 2 pixel wide rainbow and use PMGs to put the gap between each colour. Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 13, 2022 Author Share Posted November 13, 2022 1 hour ago, glurk said: What he's doing (APX Logo with 8 colored bars) is totally possible. But the GitHub code has an endless loop instead of a DLI... Please re-up code that has the DLI implemented, and I'll see if I can do it... The latest code has been uploaded. Quote Link to comment Share on other sites More sharing options...
+MrFish Posted November 13, 2022 Share Posted November 13, 2022 Here, how about something like this (quick and dirty rendition). apx logo.xex 2 Quote Link to comment Share on other sites More sharing options...
tschak909 Posted November 13, 2022 Author Share Posted November 13, 2022 1 minute ago, MrFish said: Here, how about something like this (quick and dirty rendition). apx logo.xex 3.55 kB · 0 downloads source? -Thom Quote Link to comment Share on other sites More sharing options...
+MrFish Posted November 13, 2022 Share Posted November 13, 2022 It's graph2font. Here are the source files. apx logo.zip Quote Link to comment Share on other sites More sharing options...
glurk Posted November 13, 2022 Share Posted November 13, 2022 LOL... I thought we were coding by hand here... And then up pops computer generated code, like a fish, LOL.... It's ok.......... 1 Quote Link to comment Share on other sites More sharing options...
+MrFish Posted November 13, 2022 Share Posted November 13, 2022 3 minutes ago, glurk said: LOL... I thought we were coding by hand here... And then up pops computer generated code, like a fish, LOL.... It's ok.......... What are you, the graphics police? Quote Link to comment Share on other sites More sharing options...
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