Search found 451 matches

by ob1
Fri Jan 26, 2007 3:58 pm
Forum: Super 32X
Topic: Master SH2 BIOS
Replies: 12
Views: 9904

Master SH2 BIOS

Here's a disassembly of the Master SH2 BIOS : org $0 * VBR dc.l reset ; 0: POWER ON RESET PC dc.l 0x06040000 ; 1: POWER ON RESER SP dc.l reset ; 2: MANUAL RESET PC dc.l 0x06040000 ; 3: MANUAL RESET SP dc.l forever ; 4: GENERAL ILLEGAL INSTRUCTION dc.l 0x00000000 ; 5: SEGA RESERVED dc.l forever ; 6: ...
by ob1
Fri Jan 26, 2007 3:54 pm
Forum: Super 32X
Topic: 32x "security code" reverse engineered
Replies: 26
Views: 19668

Did you manage to run both SH code actualy? Not today ! My boss won't be happy since I've done ... nothing this week !!! Once more !!! But, I've understood everything I wanted ! I get the boot process ! Next step will be to write something in Frame Buffer from just one SH2. Next step will be to plo...
by ob1
Fri Jan 26, 2007 3:47 pm
Forum: Super 32X
Topic: 32x "security code" reverse engineered
Replies: 26
Views: 19668

I've found out that the Master SH2 bios checks the initial program of the cartridge. So, it has to be present in rom, and it is present !!! From $36C to $76C !!!
by ob1
Fri Jan 26, 2007 12:48 pm
Forum: Super 32X
Topic: 32x "security code" reverse engineered
Replies: 26
Views: 19668

Fonzie wrote: Did you manage to run both SH code actualy?
Just a matter of time.
;)
by ob1
Fri Jan 26, 2007 10:41 am
Forum: Super 32X
Topic: 32x "security code" reverse engineered
Replies: 26
Views: 19668

Tasco suggested me that "MARS" was hard-wired at 0xA130EC. http://forums.segaxtreme.net/showthread.php?t=9225 Moreover, you've seen that the 32x is started from the genny RAM. I think I know why. Setting the ADEN bit changes the memory map, especially cartridge. So, if I have 0x0230 bset #1,$A15100 ...
by ob1
Fri Jan 26, 2007 8:23 am
Forum: Megadrive/Genesis
Topic: Idiot question (sorry!)
Replies: 4
Views: 3615

Planes are made of pointers to tiles, and they all reside in VRAM (the HScroll also, by the way). The scroll datas are offset. On each line, the VDP reads the planes data, and fetches the needed tiles. Then, just before sending the line to the TV screen, line is shifted regarding the offset (HScroll...
by ob1
Wed Jan 24, 2007 3:17 pm
Forum: Super 32X
Topic: Any way to run 32X VDP without hurting MD mapping?
Replies: 7
Views: 7625

The 68000 mapping relies on ADEN. Reset, you've got the usual mapping, set, you've got the alternate mapping.
I don't know if, once set, it can be reset without problem ...
by ob1
Wed Jan 24, 2007 2:48 pm
Forum: Super 32X
Topic: 32x "security code" reverse engineered
Replies: 26
Views: 19668

32x "security code" reverse engineered

Look. Devster showed us the way (I'll have to post on his forums). But I've been a little further and totally reverse engineered the security code of the 32x carts. Actually, it's more test and init than real security. There may be just 2 or 3 true tests of security, beside the facts that jumps are ...
by ob1
Tue Jan 23, 2007 4:15 pm
Forum: Tools
Topic: 32x ASM
Replies: 3
Views: 8391

32x ASM

Finally, I have found out an assembler that let me use the syntax I love : dc.l $06002000 for constants, no .text, or other, ... On SegaXtreme, Saturn Dev, go to http://www.segaxtreme.net/content/satdev/Tools.html then SN Systems ASSH & ASMSH. Use ASMSH By the way, can anyone explain to me where the...
by ob1
Mon Jan 22, 2007 4:16 pm
Forum: Super 32X
Topic: 32x ASM sample
Replies: 2
Views: 3424

Et voilà !!!
Thank you the fonz' !!!
by ob1
Mon Jan 22, 2007 10:12 am
Forum: Super 32X
Topic: 32x ASM sample
Replies: 2
Views: 3424

32x ASM sample

Has anyone got a 32x ASM sample.
I mean, something with header, security code, SH2 binary, 68k main code, easy to assemble ?
by ob1
Mon Jan 22, 2007 6:08 am
Forum: Tools
Topic: Gens32X-KMod
Replies: 15
Views: 11284

Gens32X-KMod

OK, it's a newbie question since I don't know anything about emulator.
Gens can emulate 32X. What would you need to display SH2 registers, cache, 32X main memory and frame buffer ?
by ob1
Mon Jan 22, 2007 6:06 am
Forum: Tools
Topic: Easy68K?
Replies: 21
Views: 14784

It seems to me that TOP replaces move.w #0,d0 with moveq #0,d0. I check it in 2 hours.
by ob1
Fri Jan 19, 2007 9:27 pm
Forum: Tools
Topic: Easy68K?
Replies: 21
Views: 14784

Re: Easy68K?

Stef wrote:it would be cool if the assembler can handle it (optimisation) :)
If it existed, TmEE and I wouldn't exist !

I won't live without Easy68k !!! Great tool ! The one that made me learn 68k ASM !!!
by ob1
Wed Jan 17, 2007 8:56 am
Forum: Megadrive/Genesis
Topic: Detecting the bios
Replies: 15
Views: 8485

In his Sega Genesis hardware notes ( http://cgfm2.emuviews.com/txt/gen-hw.txt ), Charles MacDonald states - Games must write the text 'SEGA' to A14000h if the lower four bits of the version register return 01h. - Writing 01h to A14101h disables the OS ROM and swaps in the cart ROM. - The OS ROM chec...