32x "security code" reverse engineered
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Maybe you should get XP compatible SNASM ?ob1 wrote:I won't swap my barrel of Charles Doty's ASM with 2 barrels of SNASM !!!
Anyway, SNASM doesn't run @ work (where 95% of my GEnesis job is done )
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SNASM68K for XP can be found at drx's site. SNASMSH2 can be found at Bart Trzynadlowski's site.
For purely 68k work, however, I recommend AS.
For purely 68k work, however, I recommend AS.
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XP and 2K are practically same, XP just has little better 9x/DOS support and is not as jerky as 2K (In my experience 2K is not much better than ME).ob1 wrote:I have Win 2000.
Where can I get one ? And SNASMSH by the way.
I got SNASMSH2 from a 32x dev thing I downloaded somewhere... Can't remember. 2K/XP SNASM68K is available at Devster's site
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Files of all broken links and images of mine are found here : http://www.tmeeco.eu/FileDen
http://www.tmeeco.eu
Files of all broken links and images of mine are found here : http://www.tmeeco.eu/FileDen
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BTW, the XP version runs flawlessly on my Win98SE machine.
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http://www.tmeeco.eu
Files of all broken links and images of mine are found here : http://www.tmeeco.eu/FileDen
http://www.tmeeco.eu
Files of all broken links and images of mine are found here : http://www.tmeeco.eu/FileDen
Re: 32x "security code" reverse engineered
Sorry to relive a topic - again !,
but there is one line of code that I find surprising.
Just between SDER and TV Mode Check, we have
If my 68k isn't too rusty, I translate this by
"write the value 0x8802a2 ... in ROM ?!"
First of all, how is it possible to write in ROM ?
Secondly, 0x70 is the offset for the Level 4 Interrupt (H INT), and 0x2a2 is the offset of the level 4 interrupt once the memory map was changed by setting ADEN. But what would be the point of copying this address ?
but there is one line of code that I find surprising.
Just between SDER and TV Mode Check, we have
Code: Select all
move.l #$8802A2,$70 ; 21 FC 00 88 02 A2 00 70
"write the value 0x8802a2 ... in ROM ?!"
First of all, how is it possible to write in ROM ?
Secondly, 0x70 is the offset for the Level 4 Interrupt (H INT), and 0x2a2 is the offset of the level 4 interrupt once the memory map was changed by setting ADEN. But what would be the point of copying this address ?
Re: 32x "security code" reverse engineered
From 32X Overview, the same as in Sega CD.
Re: 32x "security code" reverse engineered
Hello @srg320, and thank you very much for you quick answer.
Are you telling me that the custom internal ROM ($00~$FF) is actually ... RAM ?
Are you telling me that the custom internal ROM ($00~$FF) is actually ... RAM ?
Re: 32x "security code" reverse engineered
No, just area 0x70-0x73. Maybe it's a separate register.
The same register is in Sega СD and some games change it as needed.
The same register is in Sega СD and some games change it as needed.
Re: 32x "security code" reverse engineered
OK I got it.
Quite new for me, but that explains a lot.
Thank you very much ^^
Quite new for me, but that explains a lot.
Thank you very much ^^
Re: 32x "security code" reverse engineered
So,I've done my homework, and indeed, I can write at 0x70!!
Tested on Fusion and real (PAL) hardware.
Unfortunately, it looks like it doesn't work on Gens.
I can write 0x70, the KMod debug window tells me it has been modified,
but when H_INT happens, it looks like it goes to 8802A2 no matter what. May need to try a bit more on this point.
Tested on Fusion and real (PAL) hardware.
Unfortunately, it looks like it doesn't work on Gens.
I can write 0x70, the KMod debug window tells me it has been modified,
but when H_INT happens, it looks like it goes to 8802A2 no matter what. May need to try a bit more on this point.