Worklog Unnamed Xbox Portable

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Hey folks.
I have spectated a few of these competitions now, but I finally decided to throw my hat in the ring and make a fool of myself.
I never meet deadlines, and I never can think of ideas worth trying to finish within them, so frankly I am screwed, so to add insult to injury I decided to do the impossible and trailblaze the portablization of a whole new system while I do it.

The original Xbox has always been special to me since I got one at launch and I played it wayyyy too much.
My only disappointment was I had to stop playing Halo and grab a Gameboy when I left the house.
Frankly I wanna right this terrible terrible wrong, I don't wanna put Halo down dangit.

Anecdotally this is impossible and everyone will tell you so. (Just ask Shank's FAQ in his Discord server. :) )
So I should just give up now, quit while I am ahead.......or I would if I was a smart man.

The original Xbox is gigantic, it has hundreds of parts spread absolutely everywhere, and chews through power like nobody's business. The complete opposite of the Wii everyone is so fond of in these parts.
But what if I told you not all of these are the case for all of the motherboard revisions?
Microsoft produced 3 different retail PCBs for the Xbox, these were labeled as 5 different (More than that but some ended up not existing, but that's neither here nor there) different "revisions" by the Xbox modding community.

"1.0/1.1" both used the first PCB, this was by far the least streamlined board, it checked all the boxes as far as part spread and power draw. This sucker can chew through up to 68W, and is incredibly unreliable. Definitely can't use this.

A while later "1.3 and 1.4" came along, these were much improved, the layout was just better, and they pulled a little less power, up to 64W. Still not quite usable for what I want to do.

Finally in 2004 Microsoft wanted to reduce the price of the system as they were preparing for the Xbox 360, so they made the 3rd and final PCB, the "1.6"
To reduce costs they consolidated parts into custom silicon, reduced the BOM dramatically, streamlined the design to the max, and the GPU got a dieshrink!
This board fixed everything wrong with the previous revisons, and even managed to cut power draw and look dang fine doing it. This board has an incredibly dense part layout, and draws a mean 46W max!
Finally this is starting to look promising. It is a far cry from the luxuries of the Wii, but it sounds just possible enough to waste time and money screwing around with.

Here is some of my research work so far.
I have mapped out voltages, and mapped out and identified traces working my way inwards as I verified stuff could be removed.
What you see isn't tested yet (Soon!), or completely finished, but it is looking super promising, and I am excited to move forward,

Top.png


Inner.png


Bottom.png


SO, with the rambling over, now for my plans:

* Trimmed "1.6" motherboard

* 7" 800x480 IPS HDMI display

* Project Stellar and XboxHD+ for various fixes/goodies, and to get a clean digital to digital HDMI output to the display

* 4x 21700 cells for hopefully over an hour of battery life

* Custom battery management and regulator PCB(s) to handle charging/power up/regulation

* Controller PCB(s) utilizing a chip from an original controller for complete compatibility with games and homebrew

* IDE relocation to connect storage in the form of a microSD to store games/software on

That's it for now, I'll see ya when I see ya and have more to report. :)
 
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Awesome! This year looks to be like the Xbox portable year! As of now approximately how big is the projected trimmed pcb? Bigger than a DMG?
 
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That sounds very promising size wise, hopefully with enough room to jam pack your batteries in. Looking forward to seeing your progress! Whatever small step you take is a huge leap in Xbox portablizing!
 

Adan

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Xbox is a box so maybe it should be called Xpack or something because packs are usually smaller than boxes.
 
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ill be greatly disappointed if this portable doesn't have atleast a bit of Mountain dew green paint on the shell (Jk, hope it goes well!)
 

Zini

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Oh, my god. This is absolutely revolutionary. I am fawning over this. I'll be looking over this thread everyday, OG Xbox was so huge, figuratively and literally. Godspeed.
 
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Xbox is a box so maybe it should be called Xpack or something because packs are usually smaller than boxes.
When i first saw Xpack I thought of a portable xbox that's built into a backpack. Seems like a potential future project for me and significantly easier than this project.
 
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Hey!
I have mostly been swamped with farm work so I admittedly don't have much to show since the first post, but I am slowly but surely getting stuff done.
I have been working on figuring out relocations mostly, And I guess I will go ahead and talk about this a bit. :)

There are a few things that need to be relocated for the Xbox to boot, and some that fairly obviously need to be relocated to use the Xbox for anything.
With the basic trim I've outlined and will be shooting for, several things get cut off.

Relocations.png


The most important of these is the Xcalibur chip.
It's the custom video encoder chip used on the "1.6" motherboard. But it's also not "just" a video encoder. Despite the fact that I'll be using XboxHD+ for digital video (which taps into the video bus before the encoder), there's a few reasons I still need this chip.

Firstly it generates the pixel clock for the GPU, so it is still technically necessary to have it even if we're not using analog video.
Secondly, less obviously it also handles thermal monitoring by reading the CPU thermal diode.

If there's nothing doing either of these things, the Xbox will not boot.
It would be possible to feed a fixed clock to the GPU so that it only spits out 480p, and to use a standalone temp monitoring chip like the ADM1032 older Xbox boards used, but the more simple solution in my opinion for now is just to relocate the Xcalibur.
I'm still testing this, and working it out, but I should hopefully have stuff to share on that soon.

The rest of the relocations are less "important", but nonetheless are needed for a portable!
I'm just gonna run through em real quick with the diagrams I've made, as I will be going WAY more indepth in the trimming guide if/when that happens.


USB


USB is used for controllers, and memory cards, and can be easily relocated to vias near the MCPX Southbridge:

USBRelocation.png




IDE


IDE is of course used for storage, and I will be using it fo connect an SD adapter in my build, it can be relocated mostly to resistor packs near the MCPX, with a couple signals being grabbed from traces/resistors/through holes, it is harder than USB but definitely not impossible:

IDE.png



AUDIO


Finally (For now) the audio DAC is removed in the trimming process, but as I found out yesterday in my research, the Xyclops SMC (System Management Controller) ASIC on the "1.6" boards converts the weird AC97 digital audio to I2S before passing it to the DAC, which can easily be grabbed from near the Xyclops chip for use with a U-AMP2:

inkscape_6hrVhUkzoX.png


That's what I have gotten done so far, I have been way busier than I had hoped and haven't had much time to dedicate to this, but I'm gonna keep on keeping on.
In the mean time I got the screen I will be using in, so here's some photos of it! Moire effect and camera focus made it pretty hard to get photos of it, but trust me it looks amazing in person.

IMG_20230618_234813.jpg
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Alright, I will report back when I make some more progress, catch ya later!
 
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Well, as I always do I managed to neglect this worklog.

A LOT has happened since the last post, and while unfortunately I didn't make the deadline (Or the extended deadline), I made it further in these 4 months than I ever could have imagined.
I am not really sure if I can pin point where this adventure went wrong, cause really everything that could go wrong for me did at one point or another.
I had shipping delays, my weak PC slowed me down multiple days on design work, I broke stuff, I made design errors, I forgot to order stuff.....
Which is to say I got the full competition experience.

I made it to where the handheld was booting and I just had to get it to close right, which is INSANELY close to done, but even then stuff started to go wrong.
The best I was able to get was some (not closed up) videos of it technically booting, but that's it:


This project has been an immense amount of work, but it lead me to learn new skills in order to design it, and I don't think I need to tell you how valuable that is.
I will be finishing this one way or another, and improving on it, and I would like to put together a trimming guide before the end of the year.
This is only the beginning of Xbox Portables, and I hope we can all take them to new extremes beyond this "first generation" portable.

Finally, here's a couple photos of it, and with that, I guess I'm signing off on this worklog. I wish things could have gone differently, but nonetheless congrats to those who completed their builds in time!

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Retro95

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Ah finally there it is, the true steam deck killer! (Nice steam deck btw).

What's the case made out of? The end result looks THICC and got CURVES and looks super nice to hold honestly.

EDIT: Oh maybe consider naming it something along those lines. Like the Xdeck or XBdeck.
 
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Looks amazingly impressive; well done for taking on such an ambitious project!
All the work you've done will inevitably help someone else in the future.
 

Stitches

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Ah finally there it is, the true steam deck killer! (Nice steam deck btw).

What's the case made out of? The end result looks THICC and got CURVES and looks super nice to hold honestly.

EDIT: Oh maybe consider naming it something along those lines. Like the Xdeck or XBdeck.
The material looks like SLS Nylon
 
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