Zerosquare

Apologies if this is well-known.

 

I noticed something recently : Atari messed up with the Jaguar audio subsytem. (Some of you will say it's not suprising )

The Jaguar Technical Reference Manual v8 claims that the Word Strobe signal is high for the RIGHT channel, but according to the audio DAC datasheet, Word Strobe should be high for the LEFT channel.

 

There are two consequences :

• The left and right channel are swapped. I.e. the L_I2S (LTXD, $F1A148) register should be called R_I2S (RTXD, $F1A14C) and vice-versa.

  Try it -- if you write to L_I2S only, the sound will be coming from the RIGHT speaker. (I always thought I had something wrong in my cabling, turns out it's not the case).

• As the DAC expects data for the left channel before the right channel for a given sample, the I²S interrupt should be configured to occur on the RISING edge of Word Strobe, i.e. the SMODE register should be set to %001101.

Also, a related piece of advice : the I²S interrupt occurs shortly before sending the data to the DAC, so it's important to update the data registers as early as possible. If you don't, since the right data is sent first much later than the left data, it may happen than the left channel gets the data for the previous sample, while the right channel gets the data for the current sample. In other words, the channels will be out of phase by 1 sample.

 

Personally, I use code like this for the I²S interrupt :

(r2 and r3 are constants ; r2 = $F1A14C, r3 = $F1A148)

 

i2s_int:

store r0, (r2)

store r1, (r3)

movei #i2s_int_2, r30

jump (r30)

nop

nop

 

(...)

 

i2s_int_2:

; --- code to save the flags register (it's not affected by the stores) ---

 

;--- code to compute the left sample in r0 and the right sample in r1 ---

 

;--- code to restore the flags register and return from the interrupt ---

I'm a little surprised that nobody here has even mentioned their JagCode work!

We did discuss quite a bit, but that was on IRC. And as Pocket said, we did reply to a few questions on yAronet. Feel free to ask about anything specific you want to know.

 

Anyone know who did The MAXX?

I know who he is (I offered to make a video capture of his game and have it posted on Youtube), but since he replied privately, I assume he wants to remain anonymous until the voting is over. I'll just say that he's a newcomer to the Jag scene, AFAIK.

 

It does not seem to work.

OK, i'll remind RaZ about it.

 

Is this resolved?

Well, I told RaZ about it when it happened, in January. I must admit I've not done any testing since.

 

Try to archive your personal messages (without checking "Delete messages after archiving" !) and see if you receive them.

If you don't, tell me and I'll bugger RaZ again to fix it.

 

In the meantime, I've bumped the capacity of the PM boxes to 200 messages, so we'll have a little time before us.

Un joyeux anniversaire à notre écureuil préféré

Thanks

Well, the BJL loader and the communication routines work under Win98, since I've developed them on it.

Maybe there's something in your code that isn't compatible, but I can't see why.

 

About the Linux port : the last version of my BJL uploader already supports Linux

The communication routines do not yet, but they're pretty quick to port, I'll do it when I have a bit of free time.

An Atari port is a bit more work but this is doable too.

Are these games for purchase or download?

They're downloadable freely.

 

What would you recommend for the Jaguar?

I'm not much of a player, besides Tempest 2000

Have a look here to see which games are considered the best.

 

I hear there were new games developed by songbird?

Yes, songbird finished and released a few Jaguar games. You can get more info from his web page.

 

Besides eBay, you'll find links to online shops and their prices there (it's in French, but it should be understandable anyways).

 

Do you produce software here for the CD add on, or cartridges?

Our past productions have been for BJL, and released on CD as well. In the future, we will release software on Compact Flash cards to use with SCPCD's JagCF (compact flash adapter and expansion device for the Jaguar).

 

Welcome to Jagware

 

The "News" forum is for Jagware-related news (forum and team) and a requires approval by an administrator, so I've moved your post here.

 

Some retrogaming online shops still sell the Jaguar ; if you tell us what country you're from, we may be able to give you some pointers.

It's also not difficult to find on eBay, usually.

 

And yes, we've released a few homebrew games for the Jag, such as Diamjag and Atomic. Several others are currently being developed.

 

As for your Facebook group, unfortunately a Facebook account is required to view it, but I don't have one...

I think most of us use the JagView program from time to time, to check out how our graphics look like once they've been converted to 16-bit RGB or CRY format.

 

Yet it seems that there's a serious bug in 16-bit RGB mode with the blue channel. It depend on the picture, with some it's almost unnoticeable, but with others it can be quite severe as I've discovered recently :

 

Original image (24-bit RGB) :

 

Converted to 16-bit RGB and viewed with a quick program I've written. It shows dithering, but this is expected, and it looks the same on a real Jaguar :

 

Converted to 16-bit RGB and viewed with JagView :

It seems that the forum software currently is temporarily unable to send email messages.

 

Consequently, do not use the "Archive Messages" in the Messenger area. You will not receive your messages, and if the "Delete messages after archiving" option was checked, they will be lost !

 

We're sorry for the inconvenience, and we'll try to resolve this issue as soon as possible.

That's nothing, he could have spoken Welsh

If lo_inp supports Windows NT/2000/XP, it does not support Windows 95/98 then?

It does support Win95/98 as well as NT/2000/XP.

The title says it all

 

Happy birthday Brandon !

 

You're a bit early

Happy birthday !

Same thing