ForumsCodeASMObtain address of current Copperlist RSS

 

aLpHa oNe

Moin, is there any way I can obtain the address of the current displayed copperlist? Not speaking from the system Copperlist that I can find in the graphics.library structure. Somehow the custom chips do not have a READ register for $dff080. Thinking about WHDLoad there must be a possibility for this, or is the address hardcoded into the WHD Slave? Greets, Alpha
 

WayneK

Hey A1, I don't see any obvious way of doing this to be honest - I had a quick look at a few WHDLoad slaves and none of them seem to do anything other than hardcoded patch addresses. Maybe Stingray or Galahad will tell us :P
 

musashi9

How does action replay get it? C1 or C2 goes straight to the current copperlist
 

Annatar

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#3529 musashi9:
How does action replay get it? C1 or C2 goes straight to the current copperlist

Action Replay watches the Motorola 68000's bus accesses "like a hawk", to quote the Amiga Hardware internals book from Data Becker. Since it intercepts the data it knows what will be written to the CustomChips, otherwise there is no way to know since most of the memory-mapped CustomChips are write only. I always wondered why, except for memory addresses ending with "R" (like "DMACONR") most CustomChips weren't read-enabled as well.

 

WayneK

^^ What Annatar said above. You can read the full explanation by Richard Aplin here:- http://koti.kapsi.fi/~jvaltane/amiga/howtocode/actionreplay.html
 

Galahad

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In a word.... no. Whenever I need to find a copperlist, I have to go look for the code initialising it, theres no one piece of code that will do anything fancy and magically give it to you, $dff080 is write only, so unlike the Atari ST, you can't just read the register and store it for later use.
 

Annatar

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#3542 Galahad:
In a word.... no. Whenever I need to find a copperlist, I have to go look for the code initialising it, theres no one piece of code that will do anything fancy and magically give it to you, $dff080 is write only, so unlike the Atari ST, you can't just read the register and store it for later use.

Have you actually programmed an Atari ST? Is there an equivalent of the "Amiga hardware reference manual" for the Atari ST? What's a good place to start?

 

WayneK

Annatar: Atari ST Internals, ST Compendium, all the tools in the coding section of www.dhs.nu That should get you started/familiar with ST.
 

Galahad

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#3547 Annatar:
#3542 Galahad:
In a word.... no. Whenever I need to find a copperlist, I have to go look for the code initialising it, theres no one piece of code that will do anything fancy and magically give it to you, $dff080 is write only, so unlike the Atari ST, you can't just read the register and store it for later use.

Have you actually programmed an Atari ST? Is there an equivalent of the "Amiga hardware reference manual" for the Atari ST? What's a good place to start?

Yes I have programmed on the ST, had to go on a crash course and learn it quickly to do my recent ST to Amiga game conversions (Where Time Stood Still, Starquake and Ranarama). There is a specific book, I simply used a couple of online resources which simply duplicate some of the stuff in the main books.