A Message by the Sponsor

March 26th, 2015

So ok, reorganized a bit of the blog structure, fixed few bugs, converted for Mobile devices …

mobile

… changed a bit the color scheme for texts (that were a bit unreadable before).

Still ToDo:
– Remove left layout, make everything on two columns;
– Fix or get rid of link tab;
– Adjust colors for Mobile theme;

I’m open to suggestions, then the blog can relive in a new form, with more tech posts and other goodies …

Halt Catch and Fire

March 25th, 2015

Got interested in the recent Spider WIP improvements and the correlated Table Tennis Championship development, I’ve decided to take a look at this exotic FPGA-based video blitter.
The thing is definitely weird, as Haze also explained in his blog it basically reads an i/o port to enter into “blitter mode”, and any following write to the memory mapped bus actually routes to the blitter, and using the address bus instead of the data bus either for obfuscation or performance reasons.
It’s not a novelty (Sharp X1 Japanese computer line did something similar back in 1981) but definitely a bit annoying, and the main roadblock towards emulation of this game until today:

0026

0027

0030

0031

0032

Deluxe Co-Processor

September 7th, 2014

Over the past week, me and Olivier Galibert ironed out several issues in the Seibu COP simulation. This includes Zero Team not crashing anymore and this one happening …

… and yes, this one means that both Raiden 2 and Raiden DX are now (almost?) working. I have doubts especially towards DX just because I haven’t yet checked out if beating properly Alpha Stage doesn’t have issues (and yes, it’s amusing having this kind of doubt now, compared to just one week ago).

Stalling till infinity …

April 16th, 2014

Starting to work on Sega Model 2 HW, which definitely deserved some love for the importance that this HW went in mid-90s. With some aid from from Haze, providing snippets of information from ElSemi’s code here goes some WIP snaps:

Fighting Vipers
0005

Last Bronx
0003

Sega Rally (added “Eye Mode”, used by car selection)
0001

Virtua Cop
0021

0011

0019

Virtua Cop 2 (no textures, if it wasn’t clear)
0004

Virtua Striker
0004

0007

Of course it’s still a long way to go. And anyway, main problem lies in FIFO comms: BOTH CPUs stalls at arbitrary points in several games (Virtua Fighter 2, Fighting Vipers and so on), trying to read an empty FIFO instead of alternating between reads and writes.

Hyper Pipe X

December 14th, 2013

Got basic understanding about how the 3d pipeline works in Hyper Neo Geo 64. Basically it was an irq issue (one unimplemented irq is needed at FIFO processed) plus some other things like swap / clear buffer that were hooked up in the previous update.

Fatal Fury Wild Ambition

0005

0007

0008

0009

Beast Busters 2nd Nightmare

0001

0002

0003

0000

Off Beat Racer / Xtreme Rally

0035

0037

0038

0039

Roads Edge
Note: definitely behaves oddly on gameplay (most 3d missing plus unplayable)

0029

0027

Buriki One

0019

0020

Finally, both Samurai Shodown are currently with broken 3d, that’s because they sets up the 3d upload register differently compared to the other games.