English translation: Chanka programmer's interview

**Propeller** · April 20th, 2004, 21:11

Hi, I've translated this interview for you. Hope that you understand it

As we recently told you, Miguel Angel Pastor Manuel (Garrofi) is giving us every detail
of his DreamCast emulator, called "Chanka".
You can read now this interview where he tells how has he made his so called emulator "ChanKa".
Thanks, Garrofi!

Thanks very much Garrofi, for giving us the chance of this second interview, we are aware of the commotion
that the ChanKa news has arised and it has been a big impact for the whole
Spanish DC scene. But we are certain that it has not been only there,
since we have now surpassed our frontiers.

MadriDC:
We've observed that you have returned from those days of relax ... how are you M.A.?

Garrofi:
Well, but that'll be until I meet with Chanka development again...

MadriDC:
Why is your emu called Chanka?

Garrofi:
Because Chanka is our group of demos, a friends group that makes Demos for the scene.
The complete name of the emu will be ChanKa DC

MadriDC:
So, you're used to the development and stuff,
What did you do, Amiga or PC demos?

Garrofi:
PC demos.

MadriDC:
When did you had the idea of developing a DC emu and how did you approached the project?,
Are you alone or are you with the complete group Chanka?

Garrofi:
I had the idea of a next generation console emu while I was working in Pyro, and after exams
decided to work on it... For the time I'm working alone, but another partner of Chanka will join in shortly
with the sound part.

MadriDC:
If I don't make a mistake Pyro is a videogame developer, truth is it?

Garrofi:
Yeah, I was in the development of the Praetorians game, as a senior programmer of graphic
technology. But I no longer toil there, left it last year.

MadriDC 2:
Simply impressive... now I know why you have not still finished your career! ^_ ^

MadriDC:
What an experience you own, Miguel Angel!!!!

Garrofi:
I have been in Pyro 4 and a half years. To work and study is impossible...

MadriDC:
Yeah, we know it for true!

Garrofi:
Unless U doesn't have social life!

MadriDC:
It is the total cavern!!!!!

MadriDC:
Returning to the topic, as much as time takes AD with the Chanka and with what him these developing?

Garrofi:
Because from the 3ª week of February, until more or less when the first news came out. Now I have it stopped... exams, you know...

MadriDC:
Then the famous news published by pepe in Emulatronia that a Spanish programmer made a dc emu in five weeks, I understand that you were your!

MadriDC 2:
And how do you program? pure c++?

Garrofi:
C++ and x86 assembly.

MadriDC:
Atomic programming level!

MadriDC:
Do you use Direct 3D because you assure this way compatibility among all the PC?

Garrofi:
I use it because of the pleasure I have in using that. I know it better and I like it better that OpenGL.

MadriDC:
Did you already base yourself on something developed or did you begin a new project from scratch with this emulator?

Garrofi:
From 0. Although he had the experience of the nlksnes (my previous emulator)

MadriDC:
Do you emulate the SH4?

Garrofi:
Undoubtedly... if not anything would not go! what do you refer to?

MadriDC:
Sorry, I wanted to ask you if you have used a predesigned core...

MadriDC:
Ok, tell us in a nutshell how did you build up the Chanka DC.

Garrofi:
The first thing I did was a Bios dump to a file using the coder's cable and that's where I started. Everyone will have to dump their Bios, or just have it.
I wont program another Bios, although I've heard that Mr. Dan Potter programmed one by himself...

MadriDC 2:
Yes, but it never saw the light if I'm not wrong... and it was very primitive

Garrofi:
At the moment I am working with the BIOS of a PAL console

MadriDC 2:
....PAL Bios always meet some obstacles in some games, for what you would have that dump the NTSC (either JAP or it USES)

MadriDC:
I imagine that the bios carries a nice toolbox and that wince also has its part....
How much do you know of DC BIOS?

Garrofi:
Little, the little q had q to depurate. I made some HW checks and stuff, to know if everything was ok.

MadriDC:
Is It that difficult to integrate the HW emulation? as soon as you had the engine for the PVR2, the thing went better?

Garrofi:
The DC has a very well designed HW. The problem is that there is little information and I play myself to make programs to check the DC.

MadriDC:
I have enough gathered info of internet, I believe that Pablo also has...

MadriDC:
Would you like we to request everyone to collaborate in our DC forums posting information about the hardware?

Garrofi:
Yeah, nice!

MadriDC:
We'll do it.

Garrofi:
Ok

MadriDC:
How have you integrated the emulation of the DC hardware?

Garrofi:
Because then it is to go plundering the calls the software makes to the areas where the devices are mapped, the powervr, the gd-rom...
First, I got to work the IP.BINs and the some Kallistios demos.

MadriDC:
Where did you had difficulties?

Garrofi:
The asic, the nucleus q takes charge of centralizing everything. It communicates the power-vr with the sh4, the gd-rom with the sh-4 and other. The PVR2 is a graphic chip to which he receives primitive that he has to paint, and that transforms to format D3D and that's all!

MadriDC:
Did you have to make a lot of work to get your engine drawing?

Garrofi:
It is that the advantage that had is that I have a lot of experience with D3D, for what I found difficult a little.

MadriDC 2:
Which the first commercial game that you proved with the Chanka?

Garrofi:
The Sonic Adventure

MadriDC:
ISO OR CD?

Garrofi:
I didn't lose the time in making code to support isos. For the time being, alone it supports cds autoboot.

MadriDC 2:
That you can implement then, together with the execution from 1st_read.bin.

Garrofi:
Being me alone as coder made me think about a work plan, it was to make the main thing.

MadriDC:
With which PC are you emulating? When you have a version a little stable and depured, with which PC does it play games decently?

Garrofi:
I have an AMD Athlon XP 2600+ with a badge of video ATI Radeon 9700 PRO. I hope to get 30-40 fps in a PC of these characteristics...

MadriDC 2:
How many FPS do commercial games get?

Garrofi:
8 FPS

MadriDC:
Do you think that you can depure it so it would run nicer than now?

Garrofi:
I am for sure with the ideas that I have 30-40 fps a priori it is viable, but with a lot of work

MadriDC:
Ok!!!

Garrofi:
Yeah, it's good!

MadriDC:
Hey M.A, does the ChanKa have a debugger?

Garrofi:
Yeah. SH4 and ARM7.

MadriDC:
O_O

MadriDC:
How did you do with the Maple bus?

Garrofi:
The maple was no work at all, because it's well explained in marcus comstedt's website. It's a super well designed bus.

MadriDC:
When running the emu, does it pull up you the screen of the BIOS?

MadriDC 2:
It would be pretty that you took a video out of that ^_ ^

Garrofi:
That laziness to make a video... he will play You to wait.

MadriDC:
M.A. will you post more screenshots?

Garrofi:
Yes, I have q to begin to make some but Priority #1 is to optimize!

MadriDC 2:
How about implementing frameskip?

Garrofi:
he doesn't make sense, it is the cpu that takes everything. They are 2 cpus of 200 mhz and another at 25mhz

MadriDC 2:
By the way, we have opened a section in the forum dedicated to the Chanka

MadriDC 2:
When you want, and have time, you can post news and such

MadriDC:
But is it certain?, do you Come to the MadriDC 2004?

Garrofi:
I hope to be able to... he Goes to be quarreled the thing, you will see very good things in little time in DC emulators. This year will be the year of DC emulation!

MadriDC:
I think so...

Garrofi:
And not alone for my part

MadriDC:
The emu of lord cheese also takes plugins

MadriDC 2:
The Dreamer also took plugins...

Garrofi:
yes, the dreamer also took

MadriDC:
and those of Chile? that you think of their DCEmu?

Garrofi:
The difference in the emus will be in the speed and in the sound. Because if you don't have sound you can make many tricks to accelerate it

MadriDC:
But clear, not everyone has 3 Ghz PC

Garrofi:
When there is sound there is not trick.

MadriDC:
and to make something in real time with the topic of the audio?

Garrofi:
It won't be a great advance

MadriDC 2:
It would be as making a decoder of sound realtime...

MadriDC:
A question the emu goes in real time as for execution and sequence of cycles? That is to say, if the emulation of the sh4 is really 200 Mhz

Garrofi:
Yes

MadriDC:
You'll have to improve the graphic engine, won't you?

Garrofi:
They are the cheap shadows and the modifier volumes, little thing.

MadriDC 2:
Jejeje

MadriDC:
Because you take a lot of work

Garrofi:
I am a quick programmer!

MadriDC 2:
jejeje

MadriDC:
Do you interpret or do you recompile dynamically ?

Garrofi:
I have been designing the dynarec, reading theory and other, and shortly I will put on with it.

MadriDC:
Did you win a lot in speed?

Garrofi:
If I make a basic dynarec, not. he will play me to make something quite complex

MadriDC:
Optimized?

Garrofi:
he can call this way himself

MadriDC:
Brilliant

MadriDC:
Do tell us something more than the boot process ...if you turn on the emu,
is the the Bios booted ?

Garrofi:
Because it loads the bios, that appears of DC.

MadriDC:
and from there you select to pull up game and to run?

Garrofi:
If the cd is auto-boot, it is loaded

MadriDC:
Well

Garrofi:
It is like a dc

MadriDC:
OK

Garrofi:
I have not still made the VMU... alone I have the pad made.

MadriDC 2:
Can you use the boot cd to load games non autoboot?

Garrofi:
The boot-cd not, since I have not added support for cd change in the middle of the emulation.

MadriDC 2:
Interesting ^ ^

MadriDC:
I am sure that linux boots... I'll prove it!

Garrofi:
Is a thing that I have to make... does he hear, by the way, do you know where to find
the sources of the dc linux?

MadriDC:
The links are in the forums

MadriDC 2:
A pleasure to have talked with you!

MadriDC:

Miguel Angel as always has been a great pleasure to learn of a genius like you!

Greetings!

Propeller