NJ_GOKEM%FANDM.BITNET@pucc.princeton.edu (04/02/91)
From: BGBIRD::NJ_GOKEMEIJE 29-MAR-1991 16:18:35.23 To: Orig_To! ftp, NJ_GOKEMEIJE CC: Subj: Improving custom chipset! Hi out there, Since someone was suggesting improvements for the custom chipset. I would like to suggest the following: In HAM mode, there are three bit combinations that keep the color for the next pixel the same as the previous: change R by 0, change G by 0, and change B by 0. Now it seemed a good idea for me to change this into the following: change R by 0: still no color change. change G by 0: reduce all three colors by 1 change B by 0: increase all three colors by 1 This will add a lot to ham, since now it is possible to go from light to dark and dark to light, without color fringes. anyone has any comments? Offcourse this is not going to be easy, but it is possible without extra bandwidth! Nils Gokemeijer (NJ_GOKEMEIJE@FANDM.bitnet)
ckp@grebyn.com (Checkpoint Technologies) (04/03/91)
In article <49495@nigel.ee.udel.edu> NJ_GOKEM%FANDM.BITNET@pucc.princeton.edu writes: >Hi out there, > >Since someone was suggesting improvements for the custom chipset. >I would like to suggest the following: > >In HAM mode, there are three bit combinations that keep the color >for the next pixel the same as the previous: >change R by 0, change G by 0, and change B by 0. >Now it seemed a good idea for me to change this into the following: >change R by 0: still no color change. >change G by 0: reduce all three colors by 1 >change B by 0: increase all three colors by 1 > >This will add a lot to ham, since now it is possible to go from >light to dark and dark to light, without color fringes. >anyone has any comments? >Offcourse this is not going to be easy, but it is possible without >extra bandwidth! Here's an idea: Add a switchable RGB-HSV ROM (4K entries, 12 bits each) to the output of the Denise. Hook it closely enough that it can detect a write to a new custom chip register address that's currently unused, which the copper can use to enable and disable HSV mode. HSV would work much better than RGB for HAM. ...which brings up another idea: why not create a general purpose output port that the copper can write to, for enabling various similar display hacks? This would be utterly trivial, and could be added to any existing Amiga. Then HAM-E and DCTV could work without "cookies" in the image itself. C= custom-chip guys: What happens when the copper writes to a custom chip register address which is not defined? Could a third party daughterboard clipped to Denise decode that and latch the data for it's own purposes? -- First comes the logo: C H E C K P O I N T T E C H N O L O G I E S / / ckp@grebyn.com \\ / / Then, the disclaimer: All expressed opinions are, indeed, opinions. \ / o Now for the witty part: I'm pink, therefore, I'm spam! \/