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Post by jlf65 on Jan 15, 2006 13:04:05 GMT -5
Looks rather nifty with a monitor on top. Kinda like one of those old pizza-box computers. So... ported DOOM to it yet? ;D
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Jan 18, 2006 18:38:36 GMT -5
i can also tilt the computer on its side, so it's like playstation 2 style =P
DOOM? ;D, well, i didn't add the joystick port for nothing
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Post by Tom Maneiro on Jan 20, 2006 15:14:15 GMT -5
In other news, i will be learning assembler for the Z80 in my Computer Organization classes. Do you have a "Z80 for university n00bs" guide? I got a "most common instructions" guide, but sometimes it's a bit confusing.
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Post by jlf65 on Jan 20, 2006 16:27:34 GMT -5
The Z80 is really pretty simple. I learned it decades ago with the old Trash-80 computers. You can find the No Duh Guide for Z80 programming here along with some other nifty articles.
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Post by Tom Maneiro on Jan 20, 2006 18:29:21 GMT -5
WTF??! a 11 page guide that only shows registers and how to use LD instruction? At least it's something easy to learn..
"Z80 for dummies" "Now with addressing modes, TR levels and such crap for u-boobs, now only at theaters"
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Jan 27, 2006 18:09:34 GMT -5
any asembly language isn't hard to learn. the hard part is using assembly language to actually do something real useful how to add 4+2 in z80: ld a,4 add 2
there's some good+fast ways to optimize code, like how to check if hl is zero: ld a,h or l jp z,hl_is_zero
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Post by GiGaBiTe on Feb 10, 2006 4:33:16 GMT -5
rofl, doom on a OC'd 24 MHz Z80? that would be so slooow. not to mention the video chip probably couldnt support the graphics mode and it lacks color.
maybe you could make another PCB with more vram, a beter gpu and a sound chip? desoldering one of those ESS chips doesnt look that hard.
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Post by Tulio Adriano on Feb 10, 2006 11:22:34 GMT -5
LOL imagine z80 the main cpu of a system that has one of these modern NVidia FX GPUs? With DDR RAM... LOL... it could play Doom... don't forget that 32x (despite it uses 32 Bit SH2, 16 Bit MC68K) runs @ 23 MHz!
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Post by GiGaBiTe on Feb 10, 2006 13:26:38 GMT -5
i still dont see why someone hasnt unlocked the 32x's true potential at dual 28.7 MHz, because sega purposely underclocked the SH2's to 23 MHz (possibly bus problems?)
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Post by jlf65 on Feb 11, 2006 1:12:57 GMT -5
As I understand it, the 32X SH2 has the PLL hardwired to 3x the 68000 clock. Sounds like you want to change it to 4x.
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Post by GiGaBiTe on Feb 12, 2006 22:41:06 GMT -5
well:
7.68 x 3 = 23.04 MHz 7.68 x 3.5 = 26.8 MHz 7.68 x 4 = 30.7 MHz
if you did x4, you might want to put some heatsinks on the SH2's
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oompa loompa
I AM THE GOVERNATOR
"Git 'Er Dun!"
Posts: 1,301
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Post by oompa loompa on Feb 13, 2006 0:27:51 GMT -5
you're right, they could have clocked the sh2's further. i think memory wait states, and bus speeds can be selected through the software in the sh2. hardware might also have control of the wait states though, so it might not matter how the software configures the bus
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Post by GiGaBiTe on Feb 13, 2006 22:57:20 GMT -5
isn't the bus arbiter a huge bottleneck in the 32x architecture though? i read somewhere, both SH2's have to go through it and it slows things way down..
well since you added a clock selector on the 68000, doing something for the 32x shouldnt be that hard..
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Post by jlf65 on Feb 13, 2006 23:40:10 GMT -5
Well, looking at the SH2 docs, there is a way to change the clock mulitplier via software, but the values are for 1X (default on reset), 2X, and 4X. You can also only do this if the clock mode (set via hardware) is 0 to 2 (using a crystal osc). You cannot use the multiplier in external clock mode.
This leads to the conclusion that the 23MHz clock is provided outside the SH2, which is in external clock mode. I'd say there's probably a 3X PLL in the Sega custom chip. So it seems that if you want to overclock the 32X, it'll need to be by changing the clock at the cart port.
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Post by Neoid on Mar 6, 2006 5:32:34 GMT -5
Hi all! X-Monster Z80 is great project! So what about scheme to assemble this powerful system? Screenshots are not enough to be complete! I am programmer (Z80 also in my interest!! Especially!!) - i can help with powerOS to this comp.
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