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Majikeyric
Registered: Sep 2002 Posts: 83 |
How does linecrunch work ?
Hi everybody !!!!
Can someone explain or point me to a web site where I could find information about linecrunch ???
I think it allows to scroll bitmaps but I don't know how ???
thanks. |
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Nightlord
Registered: Jan 2003 Posts: 131 |
there is an article called bfli by pasi ojala in c hacking issue 10. check it out at:
http://www.ffd2.com/fridge/chacking/
there is some info about linecrunch in there about the vic fooling by d011 trickery. the best overall vic source in my opinion is vic-ii compendium at:
http://www.informatik.hu-berlin.de/~koethnig/vicii/eindex.html
all kinds of vic-ii counter fooling stuff is well explained in there |
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Majikeyric
Registered: Sep 2002 Posts: 83 |
Thanks nightlord I gonna read this ;o) |
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CyberBrain Administrator
Posts: 390 |
The VIC-article is also in nice text-format, so you can download it:
http://ftp.martnet.com/martnet/commie/documents/chipdata/VIC-Ar.. |
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tecM0
Registered: Jan 2002 Posts: 40 |
another great VIC_infopage:
http://www.minet.uni-jena.de/~andreasg/c64/vic_artikel/vic_arti..
point 3.1.14 explains linecrunch...a little bit...
tecM0/+H |
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Majikeyric
Registered: Sep 2002 Posts: 83 |
Thanks everybody !!! |
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Graham Account closed
Registered: Dec 2002 Posts: 990 |
be aware that linecrunching causes trouble on some machines. when doing linecrunching on these some bits in memory will be randomly cleared in most cases. on my flat c128 linecrunching only works after testing it several times and turning the machine off and on again between each test.... but IF it runs, all linecrunching demos and games do run.
however this is not a c128 problem like some people believe. it's a problem of VIC revisions. machines with 8562/8565 VICs don't have this problem (C64C, C64G and C128DCR). problems only occur on the flat c128, the old c128d and old c64's. i even have seen one c64 which wasn't able to do plain FLI. |
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Ninja
Registered: Jan 2002 Posts: 404 |
a c64 that cannot do FLI? Wooow, wanna have, ULTRA-RARE, big bucks on ebay!! ;)) |
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algorithm
Registered: May 2002 Posts: 702 |
It might be a power supply problem. I know it sounds very unusual.
All demo's and games which shift the screen horizontally using a graphic trick (placing specific byte combinations in $d011 followed by a self modified delay and yet another value in $d011) would seem to randomly crash the entire system.
During my C64 days (A very long time ago) I had created a small utility which would test this and give a report on the amount of bytes that were corrupted. If it did this or crashed (Due to the very possible corruption of program data) I would find that switching the system off and on would sometime solve the problem.
Mind you, this would sometimes have to be done 7 or 8 times.
After a while, I got a new power supply unit and guess what. This problem never happened again!!
I had previously read somewhere that the the linecrunch routine causes the VICII chip to draw in more power and a faulty or weak powersupply would cause memory corruption. Who knows...
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Shadow Account closed
Registered: Apr 2002 Posts: 355 |
I have this problem with my C64 (new model, not the breadbox).
Many demos that have graphic scrolling lock up after just a few seconds. Never had any issues with games though, and FLI etc. works perfectly. |
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Graham Account closed
Registered: Dec 2002 Posts: 990 |
"new model" doesn't mean anything except for the casing. it most likely still has an old board inside with 65xx ic's. |
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