| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
upper/lower border details
for fpga64 testing/checking/verifying we are looking for some info...
- opening lower/bottom border, can it be done by using y-scroll only (not switching 25/24 line mode) ? if yes, can you point at a demo that uses that trick?
- whats the absolutely last point where you have to do the 25/24 lines toggle to open the border? does it depend on y-scroll?
- please point at a demo that uses the "opposite" of opening the borders, ie "close" them to get rid of badlines and then does sprite stuff... i know there are lots but, oh well. just tell :)
yeahyeahyeah. i could probably write testcode and find it out but god, i am lazy. and someone around here probably knows it offhand anyway =) (if you think there is some more interisting stuff related to upper/lower borders, please tell aswell. except the "half open" borders from krestage1, we covered that already =P) |
|
| |
HCL
Registered: Feb 2003
Posts: 728 |
..and as usual, i don't come with answers, only gosip :P.
"closing the border" would mean to me, something like:
wait for d012=$34 (top of screen)
set d011=$1b
wait for d012=$36
set d011=$13
Then you really get a closed border with badlines and stuff but only showing $d020 :P. Quite unexplored i'd think :). This is also possible with d016, resulting in a single line of $d020, perhaps good for something..
My impression is that opening the border is not dependant of y-scroll, only y-pos(d012). |
| |
Ninja
Registered: Jan 2002
Posts: 411 |
Border flipflops are not dependant on scroll-registers; think about it, it would look odd if the borders moved with the scrolling, no? :)
If you want to disable upper/lower-border then you must do it in $f8-$fa. ($f8 being the start for the 24-line border, $fb the start for 25-line border).
Closing border != getting rid of badlines! For closing a border, do what HCL suggested, but you still have badlines (and you won't see sprites in this mode). Getting rid of badlines is switching off $d011 bit 4 when, for example, opening the upper-lower border. |
| |
Oswald
Registered: Apr 2002
Posts: 5094 |
or how about getting rid of badlines at charrow 25 and closing the borders at char 1. that would be cool :) |
| |
gregg
Account closed
Registered: Apr 2005
Posts: 56 |
This is not exactly a demo, but a small hack I made about 2 years ago for fun after I finished my first stable raster routine. It opens the upper and lower border as usual and then continues to _close_ the lower screen area by tricking the VIC into not closing the sideborder there.
http://chown.ath.cx/~greg/uploader/files/borderless.prg |
| |
chatGPZ
Registered: Dec 2001
Posts: 11386 |
Quote:Closing border != getting rid of badlines! For closing a border, do what HCL suggested, but you still have badlines (and you won't see sprites in this mode). Getting rid of badlines is switching off $d011 bit 4 when, for example, opening the upper-lower border.
ah yes...meeh =) now, what demo(s) use this? :) |
| |
HCL
Registered: Feb 2003
Posts: 728 |
I'm sorry.. I don't get what you're saying and i don't get that program running :P. |
| |
WVL
Registered: Mar 2002
Posts: 902 |
Quote: Quote:Closing border != getting rid of badlines! For closing a border, do what HCL suggested, but you still have badlines (and you won't see sprites in this mode). Getting rid of badlines is switching off $d011 bit 4 when, for example, opening the upper-lower border.
ah yes...meeh =) now, what demo(s) use this? :)
A lot of demos actually use the 'disabled screen' with 'open borders'. I guess a good example is HCL's sprite-fpp in Royal Arte :) The one on the 2nd side with the pictures fpp-ing over the full heigth of the screen.
The nasty thing about this 'mode' is that you always have to make sure you open the border each frame, otherwise the screen collapses.. |
| |
Skate
Registered: Jul 2003
Posts: 494 |
Quote: A lot of demos actually use the 'disabled screen' with 'open borders'. I guess a good example is HCL's sprite-fpp in Royal Arte :) The one on the 2nd side with the pictures fpp-ing over the full heigth of the screen.
The nasty thing about this 'mode' is that you always have to make sure you open the border each frame, otherwise the screen collapses..
Am I missing something here or are there any effects around which open the borders every N frames? As far as I know, if you are going to open the borders, you need to do it each frame no matter what. |
| |
JackAsser
Registered: Jun 2002
Posts: 2014 |
@Skate: thing is, a normal missed border open will 'only' close the border. A missed disabled screen with open border will close the whole screen. But I agree with you on this, it's not a big deal really. |
| |
algorithm
Registered: May 2002
Posts: 705 |
Not really tried the no badlines screen mode. But rather than the standard top/border removal where if its missed one frame, it can be activated the next, would the non badlines mode not work at all if a frame is missed even though its updated the next frame? |
| |
Ninja
Registered: Jan 2002
Posts: 411 |
algorithm: You can recover if you switch on $d011 bit 4 for a short time. But for most routines, this is a special case. Usually, you switch this bit off and keep it this way...
gpz: Darwin uses it in the Test-Bit-Digi-part. For a tiny testcase, try Borderless. |
