| |
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. |
|
... 23 posts hidden. Click here to view all posts....
|
| |
yago
Registered: May 2002
Posts: 333 |
Concerning different CIAs:
There is a way of detecting them, one type needs longer for an IRQ (mist's diag-prg did this)
I also discovered memory-faintings when fidling with D011 on a "all-new" c64, and concluded that this does only happen when the c64 is not switched on a long time.
Don't know if this due to power-supply or other things..
Murphys Law regarding linecrunching:
It works on all machines, except on the organizers one.
|
| |
Cybernator
Account closed
Registered: Jun 2002
Posts: 154 |
Stryyker wrote:
"I think the A means 2MHz mode available too."
I understand using this chip in C128, but why would someone use it in a C64C ??? I've even seen CIAs like "6526A-1" and "6526B". What teh heck does this mean? :/
Yago wrote:
"Concerning different CIAs:
There is a way of detecting them, one type needs longer for an IRQ (mist's diag-prg did this)"
You mean the IRQ occurence is delayed? (In case I understood you right). I just made a little test-routine which uses double raster interrupt to stabilize, and then starts timer A of CIA1, which then generates interrupt and changes the border color. (DEN is set to 0, btw).
Then I've used both version of CIA, and the color change happened exactly at the same place.
I've probably misunderstood ya. Where can I find the routine you mentioned?
Yago wrote:
"I also discovered memory-faintings when fidling with D011 on a "all-new" c64, and concluded that this does only happen when the c64 is not switched on a long time.
Don't know if this due to power-supply or other things.."
Ok, I realize my English sux :P Do you mean the C64 was NEW-VERSION, or it was new (NOT RAPED)? :) Or maybe all NEW-VERSION _C64s_ you have tried?
Never noticed such a problem. Only that those grey dots (when changing border/paper color) may appear or disappear when switching the C64 on/off.
Yago wrote:
"Murphys Law regarding linecrunching:
It works on all machines, except on the organizers one."
Hehe :-) |
| |
yago
Registered: May 2002
Posts: 333 |
To recognize the both CIAs (6526 & 8???), try the Program "diag" which might be found here:
http://www.weihenstephan.org/~michaste/mxass/
If it not included inside the Assembler anymore, contact me.
My "new C64" has all new Chips, SID, VIC, everything.
It has also a green LED, and msmakelas shiftlock-detection does not work as reliable as on other C64s (which seems to be an attribute of the mainboard/cia, NOT the keyboard).
I have also other "new version" c64 (to be honest, I use only non-breadbox-c64), but most of them have "old" chips.
The "dot"-problem can be used to manually detect a new VIC.
lda #0
sta $d011
loop: sta $d020
jmp loop
PS: "old" chips = 6xxx
"new" chips = 8xxx
|
| |
Cybernator
Account closed
Registered: Jun 2002
Posts: 154 |
Yago wrote:
"To recognize the both CIAs (6526 & 8???), try the Program "diag" which might be found here..."
Wait a minute, I've never seen 85xx CIA. New C64s are based on 85xx chips, except for the CIA. It still 6526 with "A" after the number. Or maybe there're some 85xx based CIAs which are unknown to me? If possible, please check the number of the CIAs in your C64.
Btw, please explain something more about the "shiftlock detection" you mentioned (or send me a link if there's any).
|
| |
Stryyker
Registered: Dec 2001
Posts: 469 |
My newer C64 had red LED. |
| |
yago
Registered: May 2002
Posts: 333 |
Quote: Yago wrote:
"To recognize the both CIAs (6526 & 8???), try the Program "diag" which might be found here..."
Wait a minute, I've never seen 85xx CIA. New C64s are based on 85xx chips, except for the CIA. It still 6526 with "A" after the number. Or maybe there're some 85xx based CIAs which are unknown to me? If possible, please check the number of the CIAs in your C64.
Btw, please explain something more about the "shiftlock detection" you mentioned (or send me a link if there's any).
Concerning differences between left shift and shiftlock:
This is an excerpt from C=Hacking #7:
You can use this feature to distinquish between the left
shift and the shift lock keys, although they are connected
to same hardware lines. The shift lock key has smaller
resistance than the left shift. If you make both CIA 1
ports to outputs (write $FF to $DC03 and $DC01) prior
reading the left shift key, only shift lock can change the
values you read from CIA 1 port B ($DC01).)
Have Fun,
Zed Yago
|
| |
ChristopherJam
Registered: Aug 2004
Posts: 1423 |
So I've been playing with line crunch a little, but if I try to do it within the display area, I've only managed to crunch every second row of characters.
(eg, I can get VIC to display 8 lines of row 3, then 1 line of row 4, then 8 lines of row 5, then 1 line of row 6)
Within row 3, I tell VIC to delay row 4 by a line, then trigger row 4 at the time I would for FLI (ie with the three char bug area visible). I can then start row 5 in any of the next 7 lines.
Is crunching multiple adjacent rows down to single adjacent lines only possible if you start in the upper border, before the first char row has been displayed? |
| |
ChristopherJam
Registered: Aug 2004
Posts: 1423 |
Never mind, got it working now :D |
| |
Raistlin
Registered: Mar 2007
Posts: 757 |
I'm starting to code my first linecruncher (!) .. and hitting some snags. I can only get it to scroll 0-14px (!) instead of the 0-15px that I of course want...
Across 16 frames, I'm doing these D011 writes (VSYNC, HSYNC):-
Frame0: V01, H15 (D011 = $30) and V48, H09 (D011 = $31)
Frame1: V01, H15 (D011 = $31) and V49, H09 (D011 = $32)
...
Frame6: V01, H15 (D011 = $36) and V54, H09 (D011 = $37)
Frame7: V01, H15 (D011 = $37) and V54, H09 (D011 = $30)
Frame8: V01, H15 (D011 = $30)
Frame9: V01, H15 (D011 = $31)
..
Frame15: V01, H15 (D011 = $37)
These are the only $d011 writes that I do...
Frame7 and Frame8 end up the same .. so it seems that I have something out of step somehow - both frame 7 and 8 of course have a final $d011 value of $30... so I assume I'm doing -something- wrong here..?
Any help/advice at all would be great............ |
| |
Raistlin
Registered: Mar 2007
Posts: 757 |
One more small note with what I'm trying to do here ... I'm -hoping- that I can do 0-15px linecrunch-based scrolling without losing any of the vertical height of the screen .. ie. retaining all 24chars (192px). |
| Previous - 1 | 2 | 3 | 4 - Next |
