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Atari coding BBS
| Another STE question |
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Posted by: Bod/STAX
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May,10.2012-20:28
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According to the following link:
http://atari-ste.anvil-soft.com/html/devdocu3.htm
When starting the blitter to perform an operation in shared mode you should do the following loop to hand the 64 cycles allocated to the 68k back to the blitter to get the best results:
loop: bset #7,$fffff8a3c.w
nop
bne.s loop
However I've always though that the following is the best way to do it if you need to switch off the blitter under interrupts as well as performing an operation in shared mode (Griff of IC does it this way too):
loop: btst #7,$fffff8a3c.w
nop
bne.s loop
Which is actually the best method?
Also a while back I posted about a problem with the blitter interferring with timer b lower border code. I came up with a way to fix it but I've now found out that I get a graphical glitch with it, so I just want to clarify the way it was originally suggested I do it here:
lower_border: bclr #7,$fffff8a3c.w ; turn off blitter
move.w sr,old_sr ; save sr state
move.w #$2100,sr
stop #$2100
move.w #$2700,sr
; here do the usual border removal stuff (wait for right border, do 60/50
; switch
bset #7,$fffff8a3c.w ; turn on blitter
move.w old_sr,sr ; restore sr state
rte
The above code is called on line 198 (instead of 199) and waits for one extra scanline before removing the lower border?
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Topic
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Posted by
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Date
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Another STE question
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Bod/STAX
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May,10.2012-20:28
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Re: Another STE question
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RA/pdx
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May,11.2012-11:56
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Re: Another STE question
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Bod/STAX
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May,11.2012-13:06
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Re: Another STE question
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Cyprian
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May,11.2012-13:17
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Re: Another STE question
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RA/pdx
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May,11.2012-21:04
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Re: Another STE question
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Bod/STAX
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May,12.2012-12:41
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Re: Another STE question
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evil
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May,12.2012-14:45
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Re: Another STE question
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Bod/STAX
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May,12.2012-17:56
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Re: Another STE question
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evil
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May,12.2012-18:24
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Re: Another STE question
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Bod/STAX
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May,12.2012-21:20
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Re: Another STE question
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evil
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May,13.2012-13:17
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Re: Another STE question
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Frank b
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May,14.2012-20:16
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Re: Another STE question
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Cyprian
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May,13.2012-18:22
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Re: Another STE question
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Patrice Mandin
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May,13.2012-14:38
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Re: Another STE question
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Bod/STAX
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May,15.2012-11:15
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Re: Another STE question
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evil
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May,16.2012-09:17
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Re: Another STE question
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Bod/STAX
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May,16.2012-21:30
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Re: Another STE question
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evil
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May,16.2012-22:40
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Re: Another STE question
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Bod/STAX
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May,17.2012-01:10
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Re: Another STE question
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Klaz
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May,17.2012-14:08
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Re: Another STE question
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Bod/STAX
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May,17.2012-21:35
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Re: Another STE question
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dan/pdx
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May,18.2012-16:03
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Re: Another STE question
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Bod/STAX
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May,18.2012-20:24
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Re: Another STE question
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Bod/STAX
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May,19.2012-16:21
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What's the anti-troll code?
That's your personal code to be able to add comments and messages on the dhs.nu site.
Don't have a code or forgot it? Fix it here.
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