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Overclocked Jaguar

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Hi !

 

(from Jaguar Mods topic :) )

I think Fredifredo is thinking about something else that's going to be revealed soon icon_wink.gif

 

The new mod for the jaguar is the Overclock !

 

It was the 3rd June that I have success to overclock the Jag, but no time to make videos ;)

All my cartridge games (about 33) work perfectly on the overclock jaggy at all tried frequency except that the sound is played more quickly and some music player of games have bugs, but it's perfectly playable (when it's not too accelerate :ponder: ) !

The JagCF works perfectly as well.

 

Photos of the overclock jaggy :

First try :

post-5715-1183915114_thumb.jpg

Fixed mod :

post-5715-1183915168_thumb.jpg

 

Videos at different speed :

 

The FastLara demo by Orion_ with VBL consumption in red : (it's a PAL demo and on a NTSC jag some part of the screen are cutted)

 

FastLara @ 32MHz (68K @ 16MHz)

 

FastLara @ 37.5MHz (68K @ 18.75MHz)

 

Then on a game :

 

Zero5 @ original speed (26.59MHz -> 68K @13.295)

 

Zero5 @ 32MHz (68K @ 16MHz)

 

Zero5 @ 37.5MHz (68K @ 18.75MHz) (onYoutube)

 

At 37.5MHz, the jag cube on startup is distort and the jag can crash. (this why I launch the game before it appears)

 

I tried to 40MHz but the Jag crash on startup. It's, for me, normal because the 68K is already over it's limit which is 16.67MHz from the datasheet.

 

 

Cheers !

 

Edit : videos reuploaded :) (less size)

Edited by SCPCD
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Nice. Too bad the mod isnt more usable. I wouldnt like to play with bad sound. But still an awesome mod nontheless.

 

BTW I thought the JagCF wasnt out yet.

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Hi !

 

(from Jaguar Mods topic :) )

I think Fredifredo is thinking about something else that's going to be revealed soon icon_wink.gif

 

The new mod for the jaguar is the Overclock !

 

It was the 3rd June that I have success to overclock the Jag, but no time to make videos ;)

All my cartridge games (about 33) work perfectly on the overclock jaggy at all tried frequency except that the sound is played more quickly and some music player of games have bugs, but it's perfectly playable (when it's not too accelerate :ponder: ) !

The JagCF works perfectly as well.

 

Photos of the overclock jaggy :

First try :

post-5715-1183915114_thumb.jpg

Fixed mod :

post-5715-1183915168_thumb.jpg

 

Videos at different speed :

 

The FastLara demo by Orion_ with VBL consumption in red : (it's a PAL demo and on a NTSC jag some part of the screen are cutted)

 

FastLara @ 32MHz (68K @ 16MHz)

 

FastLara @ 37.5MHz (68K @ 18.75MHz)

 

Then on a game :

 

Zero5 @ original speed (26.59MHz -> 68K @13.295)

 

Zero5 @ 32MHz (68K @ 16MHz)

 

Zero5 @ 37.5MHz (68K @ 18.75MHz) (onYoutube)

 

At 37.5MHz, the jag cube on startup is distort and the jag can crash. (this why I launch the game before it appears)

 

I tried to 40MHz but the Jag crash on startup. It's, for me, normal because the 68K is already over it's limit which is 16.67MHz from the datasheet.

 

 

Cheers !

 

Edit : videos reuploaded :) (less size)

 

 

Um...you had to have rewritten the boot rom. the boot rom set values to the video based on

a 26 mhz clock, not any of the others. How are you managing that if not altering the boot ROM?

Are you upping the video clock accordingly as well? Not suprising that the sound plays faster.

 

I replaced the system clock once with a 32 mhz crystal and the game worked but the video

was rolling and skewing and not neglegable. The music played faster and the system ran well

and I used only two heavy blocks of metal as temp heat sinks.

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Um...you had to have rewritten the boot rom. the boot rom set values to the video based on

a 26 mhz clock, not any of the others. How are you managing that if not altering the boot ROM?

Nop.

It's not needed to change the boot rom configuration. (and I think that some games change video configuration so it could be a problem)

 

In fact, the jaguar video chip is so well designed that it has different input clock : one for the video generator and another for the core.

So, the only thing to make is to separate on the board the video clock to the general clock (that is already made for first generation jaggy with a patch) and give another clock for the system clock ;)

Very easy task. :)

 

Not suprising that the sound plays faster.

Yes, it's totaly normal that the sound plays faster because in contrast to TOM, Jerry has the same clock for all the core.

 

I haven't try to have different clocks for TOM & Jerry & 68K but I think that the system will crash.

Edited by SCPCD

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I want to do this mod. mostly for the polygon games that need a spped increase. If it's just music that is effected then I don't care, I always shut the music off anyway, but are sound effects alright?

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So, the only thing to make is to separate on the board the video clock to the general clock (that is already made

 

Ok so you had to cut a trace on your Jaguar? That makes sense then. Would be cool

to up the vid clock to so you could attain higher resolutions with a higher pixel clock.

Wonder if the Tom video could handle a faster pixel clock.

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So, the only thing to make is to separate on the board the video clock to the general clock (that is already made

 

Ok so you had to cut a trace on your Jaguar? That makes sense then. Would be cool

to up the vid clock to so you could attain higher resolutions with a higher pixel clock.

Wonder if the Tom video could handle a faster pixel clock.

 

 

also you definitely dont want seperate clocks on the riscs.

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That's pretty cool that you can overclock the Jaguar! :)

technically you can overclock any game systems :P with some it's just not worth the effort, I've seen some cool overclocked TG-16's, though sped up sounds are a universal side effect to it (correct me if I'm wrong programmers :P ) Theirs also a mod to replace the processor in the Genesis with the successor to that chip with 80% compatability but as with most tinkerings, you lose some and gain some...

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What happens with the JagCD?

Oh, yes I haven't try with the JagCD, I will try sooner or later ;)

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Ok, I just watched the videos, impressive, now if only my Jag would run at this speed ! :P

Edited by Pocket

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I've got some questions about the 68000's speed. If it's normal speed is ~13MHz, why is the chip clearly labeled 16MHz? And if it is capable of running at 16MHz without problems, wouldn't it make a big improvement to most Jag games that use the 68K as the CPU if just the 68K were "overclocked" at 16MHz? Also, the Tom chip is clearly labeled "CPU" so why do non-believers always claim the 68K at the "CPU?"

Edited by Gunstar

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I vaguely remember some of my jaguars having 13mhz (or was it 12mhz) 68000 and a few having 16mhz (which I'm pretty sure was just clocked down onboard some way). I always wondered the same thing.

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When it says the 68000 is a 16MHz chip it just means it is tested and able to run at 16Mhz. You can clock it at 12 MHz if you want or 8Mhz, or slower. That rating is just the "high" end guaranteed by Motorola.

 

No different than how Intel and AMD do it.

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I've got some questions about the 68000's speed. If it's normal speed is ~13MHz, why is the chip clearly labeled 16MHz? And if it is capable of running at 16MHz without problems, wouldn't it make a big improvement to most Jag games that use the 68K as the CPU if just the 68K were "overclocked" at 16MHz? Also, the Tom chip is clearly labeled "CPU" so why do non-believers always claim the 68K at the "CPU?"

 

 

The problem with those designations of CPU is they just dont apply. I believe CPU was used

not to introduce more confusing terminology, however that did not seem to work either. Any

risc or the 68k can be the CPU. I can and have run code on the 68k only, the GPU only and

the DSP only, controling all the other parts of the system. there is no exclusive CPU. The 68k

is only a boot manager and as Atari claims only there to read the joysticks. It is not the

CENTRAL point of processing in the Jag by any means. the GPU does come closest but still

does not apply as CPU.

 

In a typical systems(which the Jaguar is NOT) you have a CPU such as the Intel or AMD. It is

the ONLY master in the system. It sends commands to a sound or gfx card and those commands

trigger interenal processes of those cards. The processors on those cards cannot 'take over and

control' the other parts of the PC like the GPU or the DSP or the 68k can. Only one processor can

be a CPU in a system like the PC. Yes the graphics and sound card may be able to be granted control

of the bus for data but they cant run code out there or maintain control permanently. There is no

such limitation on the Jaguar design. You can't use terms and definitions of old school tech to define

new and clearly different technology. It is why we had a forty page arugment over the Jaguar and

it's bitness.

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When it says the 68000 is a 16MHz chip it just means it is tested and able to run at 16Mhz. You can clock it at 12 MHz if you want or 8Mhz, or slower. That rating is just the "high" end guaranteed by Motorola.

 

No different than how Intel and AMD do it.

 

You can indeed overclock a 68k but not by much more than its rating.

They tend to be VERY tempermental even after a mhz or two increase

past the rating.

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Why overclock the 68k? Why not just drop it completely and use the faster GPU?

 

I think it was "just for fun"

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Heyyy... maybe you can get past the intro in the Surrounded Demo Gorf made a lot quicker with this. :P

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