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H.O
Account closed
Registered: Oct 2002
Posts: 70 |
cleaning up between demoparts
One of favorite projects (or maybe not) -- I am currently trying to integrate some code made by others (basically, I am planning to do a release of some unreleased demo parts)
Problem is, one of the demo parts seems to be assuming a helluva lot of the c64. If I link the parts together, and do a soft reset I can start the last part with no problems.
But, if I have run some other demo part first, this part will just freeze up.
But, since I dont want anyone to have to use soft reset inside a demo, I want to clean up so that the final part works fine. Currently I am using the following calls:
sei
jsr $ff5b ; Initialize screen editor
jsr $fda3 ; Initialise I/O
jsr $fd15 ; Restore Kernal Vectors
lda #$00
ldx #$00
cleanme
sta $d800,x
inx
cpx #$28
bne cleanme
cli
Anything else that I can do? I am trying to avoid my worst case scenarios (which are releasing each part as they are as standalone applications, or rewriting most of the code that I didnt do; none af them are very appealing to me)
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Kaizen
Registered: May 2009
Posts: 24 |
Hi,
if I want to init only the screen editor leaving unchanged VIC registers, could I use JSR $E51B instead of JSR $FF5B os there are contraindications (e.g. Kernal modified or so...)?
THX. ;-) |
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Oswald
Registered: Apr 2002
Posts: 5076 |
how about copying the kernal routine to the ram below, and patching the vic reg writings ? |
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Kaizen
Registered: May 2009
Posts: 24 |
If I call $FF5B, and this address then will call $E518.
The first subroutine which get called at the address $E518 is the one that starts at $E5A0 and it's the one that sets the values of the VIC, but I want to bypass it.
So the idea is to do a direct call to the routine that stars right after $E51B.
But I've a doubt about the compatibility.
I don't that if I call directly the routine at $E51B could create problems in case of modified kernals (ie: speed dos or similiar, which I assume using a kernal ROM modified, so it could possible a system crash, in this case).
Or not?
THX. |
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Oswald
Registered: Apr 2002
Posts: 5076 |
it may be incompatible, but a stock rommed c64 is considered and used as the standard anyway, so I dont see it as a show stopper. |
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chatGPZ
Registered: Dec 2001
Posts: 11293 |
from my experience, you almost always want to implement your own version of the reset routine. especially from a demo point of view the kernal routines suck hard.
(wtf, i read "cleaning up between demoparties" ... /o\) |
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Stainless Steel
Registered: Mar 2003
Posts: 966 |
Cleaning up after a demoparty must be a worse job than jizzmopper in a stripjoint :-) |
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