Search found 410 matches

by ob1
Mon Jul 20, 2009 7:00 am
Forum: Super 32X
Topic: Shared Memory
Replies: 16
Views: 8010

Comm Port (8 16-bits words) should fit.
by ob1
Fri Jun 12, 2009 7:18 am
Forum: Megadrive/Genesis
Topic: Question on Programming Fighting games on the Mega Drive
Replies: 19
Views: 9066

... anyway, what was the difference between SF2T (SNES) and SF2'CE (Genny) ?
by ob1
Wed Jun 03, 2009 9:09 am
Forum: Controls
Topic: SEGA Mouse
Replies: 2
Views: 9736

It actually is !
Great work !
by ob1
Tue Jun 02, 2009 8:49 am
Forum: Megadrive/Genesis
Topic: Question on Programming Fighting games on the Mega Drive
Replies: 19
Views: 9066

plee wrote:SF3 was not that much of a difference than SF2 as far as graphics
+1
by ob1
Thu May 28, 2009 7:03 am
Forum: Megadrive/Genesis
Topic: Question on Programming Fighting games on the Mega Drive
Replies: 19
Views: 9066

Please, keep quiet gentleman.
by ob1
Tue May 12, 2009 6:54 am
Forum: Super 32X
Topic: Super VDP
Replies: 167
Views: 93702

Sure.
Let r1 = 40516273

Code: Select all

mov.l UNPACK_MASK,r0
mov r1,r2     ; r2 = 40516273
and r0,r1 r   ; r1 = -0-1-2-3
shlr2 r2
shlr2 r2      ; r2 = -4051627
and r0,r2     ; r2 = -4-5-6-7


UNPACK_MASK: dc.l $0F0F0F0F

Well, I lied. 6 cycles.

Toto©
by ob1
Mon May 11, 2009 7:14 am
Forum: Super 32X
Topic: Super VDP
Replies: 167
Views: 93702

Wisely and slow ;)
by ob1
Sun Apr 26, 2009 9:02 pm
Forum: Super 32X
Topic: Super VDP
Replies: 167
Views: 93702

It IS actually very clever ! 1 byte per line, containing 8 bits, 1 bit per pixel, 0 = transparent, 1 = not transparent. Then a Lookup Table. (Note for myself : beware, the mask may be interlaced or unpacked. The jump table has to be set this way). I have more than 128kB for tiles, so, room for more ...
by ob1
Sun Apr 26, 2009 8:41 am
Forum: Super 32X
Topic: Super VDP
Replies: 167
Views: 93702

I don't think the O/W makes a read from current FB, compare with value to write, and, if this value is 0x00, lets the current FB untouched. I'd rather think about a simple logic circuitry. So it is quite fast. Then there's the VDP, and the FIFO that makes it 5 cycles long when full. And that isn't t...
by ob1
Sat Apr 25, 2009 8:10 am
Forum: Super 32X
Topic: Super VDP
Replies: 167
Views: 93702

As you and Snake said, the VDP is between 3 and 5 cycles long.
I guess the O/W is connected to the VDP, so it should be 3-5 cycles long.
by ob1
Thu Apr 23, 2009 7:30 am
Forum: Super 32X
Topic: Super VDP
Replies: 167
Views: 93702

Propagation and multiply

Well ... heaven is not here yet ! MUL.L is a damn slow operation : IF ID EX (stalls CPU) MA MA (yes, twice !) and mm mm mm mm. 9 steps, 10 cycles and a lot of stalls. With that in mind, I can only have 6 instructions (besides MUL.L and STS.L) in 12 cycles. It ain't faster than classic propagation an...
by ob1
Tue Apr 21, 2009 2:06 pm
Forum: Super 32X
Topic: Super VDP
Replies: 167
Views: 93702

Transparency and propagation

Let's say we have a tile line (1 32 bits longword) : 40516273 I unpack them in ~5 cycles and get 2 32-bits longword : -0-1-2-3 and -4-5-6-7 Previously I interlaced them with the pal so to get : p0p1p2p3 and p4p5p6p7 If you're in A plane (background), no problem, you're going to overwrite previous pi...
by ob1
Wed Apr 15, 2009 7:02 am
Forum: Megadrive/Genesis
Topic: Question on Programming Fighting games on the Mega Drive
Replies: 19
Views: 9066

The fonz has made some tries with huge sprites decompressing. See his site.
by ob1
Sat Mar 28, 2009 8:38 pm
Forum: Megadrive/Genesis
Topic: Mickey Mania emulator comparison
Replies: 67
Views: 32333

Ok, so I think I've finished messing around with my sprite test rom for the time being. Here's the ROM: http://nemesis.hacking-cult.org/MegaDrive/Roms/Test/Mine/VDP/SpriteMaskingTestRom.bin And here's the source: http://nemesis.hacking-cult.org/MegaDrive/Roms/Test/Mine/VDP/SpriteMaskingTestRom.zip ...
by ob1
Wed Mar 25, 2009 1:27 pm
Forum: Blabla
Topic: Patent numbers
Replies: 5
Views: 4024

Patent numbers

Reading http://gendev.spritesmind.net/forum/viewtopic.php?p=8305#8305 , I've wandered a bit around Google Patent which is a great piece of ... curiousity (I wouldn't talk about knowledge). Anyway, here it is : TMS9918 4243984 Sonic2 5513307 32X 5692162 Massive 32X 5471579 3DO 5596693 SuperFX 5357604...