XycloMod: flash the on-board BIOS on v1.6

[HarryButt]

Same code on both chips? 

[Prehistoricman]

5 hours ago, HarryButt said:

Same code on both chips? 

Yes

5 hours ago, vhs said:

Got it done on my console, amazing work!

I'm having video issues after having removed those resistors, my component cables I made from a set of 360 cables now do not work and I'm having trouble figuring out just what i need to do to restore that functionality.

Yeah the console gets confused about the video mode, so you need to put the resistors back (or just a solder blob across the pads). I'll add it to the tutorial.

[vhs]

47 minutes ago, Prehistoricman said:

Yes

Yeah the console gets confused about the video mode, so you need to put the resistors back (or just a solder blob across the pads). I'll add it to the tutorial.

I bridged the points where I pulled the resistors off, I get composite video fine now, and when trying to use component I get no signal for about 3-4 seconds, then a quick flash of the cerbios logo, then no signal again. I can hear the menu though so I'm not sure how to remedy this. I fed it into my GBS-C and I see more of the boot up, but then it loses video again when it gets to the unleashX dash.

Edited May 7 by vhs

[Prehistoricman]

5 hours ago, vhs said:

I bridged the points where I pulled the resistors off, I get composite video fine now, and when trying to use component I get no signal for about 3-4 seconds, then a quick flash of the cerbios logo, then no signal again. I can hear the menu though so I'm not sure how to remedy this. I fed it into my GBS-C and I see more of the boot up, but then it loses video again when it gets to the unleashX dash.

Can you show a photo of the soldering? Do you get the same issue with a modchip?

[vhs]

12 hours ago, Prehistoricman said:

Can you show a photo of the soldering? Do you get the same issue with a modchip?

Here is the soldering. I was never able to get a modchip working on this console, I was actually in the middle of trying when this was released and figured I'd try the xyclomod.

[Timmit99]

After completion of the flash, would the 1.1.1 (Debug to 3v3 connection) need to be removed to take the Xyclops out of Debug mode?

[HarryButt]

57 minutes ago, Timmit99 said:

After completion of the flash, would the 1.1.1 (Debug to 3v3 connection) need to be removed to take the Xyclops out of Debug mode?

My understanding of this is once you are done if you want full av port compatibility you will need to remove 3.3v  and re-tie pins 18 and 6 to gnd. 

The av pins used to get access to the Xyclops serial bus are the same pins cables use for jumpers to hard set video modes  

Edited May 8 by HarryButt

[Prehistoricman]

21 hours ago, vhs said:

Here is the soldering. I was never able to get a modchip working on this console, I was actually in the middle of trying when this was released and figured I'd try the xyclomod.

Soldering looks great. I can only think that maybe the SMC is corrupted. If you want to look into it, can you reconnect the serial, run xyclops_dumper.py from the repo (after adjusting the port name on line 3) and compare the resulting dump.bin file to the P2L.bin file in the repo?

16 hours ago, Timmit99 said:

After completion of the flash, would the 1.1.1 (Debug to 3v3 connection) need to be removed to take the Xyclops out of Debug mode?

It's best to remove the debug connection yes. This will prevent any accidental entry to the debug mode which would freeze the xbox.

Edited May 9 by Prehistoricman

[vhs]

On 5/9/2025 at 5:58 AM, Prehistoricman said:

Soldering looks great. I can only think that maybe the SMC is corrupted. If you want to look into it, can you reconnect the serial, run xyclops_dumper.py from the repo (after adjusting the port name on line 3) and compare the resulting dump.bin file to the P2L.bin file in the repo?

It's best to remove the debug connection yes. This will prevent any accidental entry to the debug mode which would freeze the xbox.

So I did a successful modxo install on another 1.6 I had to get some redemption on that first failed attempt, and was having the same issue as my xyclomod 1.6. Either it would only output grayscale over component or do composite perfectly fine. I ended up realizing that PrometheOS on the modxo had 720p enabled (by default? not sure) and that disabling that returned component functionality to the console on my crt. I am wondering if there is something similar going on with the 1.6 I did the xyclomod on? The behavior is identical, I just don't know where the setting for that would be since it isn't using PrometheOS.

edit: looking at the brief image of the cerbios startup, it looks like the logo is in widescreen when it flashes on my crt. The logo looks squished like its 16:9 compressed to 4:3.

Edited May 12 by vhs
additional information

[ModderFokker]

57 minutes ago, vhs said:

So I did a successful modxo install on another 1.6 I had to get some redemption on that first failed attempt, and was having the same issue as my xyclomod 1.6. Either it would only output grayscale over component or do composite perfectly fine. I ended up realizing that PrometheOS on the modxo had 720p enabled (by default? not sure) and that disabling that returned component functionality to the console on my crt. I am wondering if there is something similar going on with the 1.6 I did the xyclomod on? The behavior is identical, I just don't know where the setting for that would be since it isn't using PrometheOS.

edit: looking at the brief image of the cerbios startup, it looks like the logo is in widescreen when it flashes on my crt. The logo looks squished like its 16:9 compressed to 4:3.

Did you skip the resistor part in the guide?

[vhs]

1 minute ago, ModderFokker said:

Did you skip the resistor part in the guide?

I followed the guide exactly as it said to do the mod

[vhs]

1 hour ago, vhs said:

I followed the guide exactly as it said to do the mod

I have solved the issue. After flashing Cerbios it defaulted to all video modes enabled. My CRT couldn't read it, and apparantly my GBS-C couldn't read it either. I just happen to think to dig out my OSSC and try that and thankfully it was able to read the signal and get those modes disabled and now it works properly over y/pb/pr. Sorry for starting a wild goose chase and thank you very much to yall giving me your time trying to help solve the issue. Much appreciated.

[HarryButt]

Word on the street is Prehistoricman has a B01 on the way 'to play with' 

Edited May 23 by HarryButt

[Versatile]

On 5/5/2025 at 10:49 AM, b3ncs1 said:

for those want to use a pico, i wrote down the whole process that worked for me

- i used this exact fw: https://github.com/JoeSc/pico-sexa-uart-bridge
- i soldered in the connections on the picture with 40awg wire
- the pico emulates 6 com ports, and i used the 4. one, you have to test it which works for you
- verified with a stock bios dump from an 1.6 to ensure the communication between the pc and the console is flawless. (note: i couldn't dump the bios succesfully with the dumper script.)
- when the stock bios verification ended succesfully i flashed the cerbios.bin

note 2: you can make soldering the txd via easier if you scratch it a little with an exacto knife
note 3: i used the lpc port ground point

I was able to dump the stock bios, but can someone confirm the dump is 64 kilobytes? Verifying it was good, just wanted to confirm as cerbios is 256 kilobytes.

Edited May 24 by Versatile

[Prehistoricman]

13 hours ago, Versatile said:

I was able to dump the stock bios, but can someone confirm the dump is 64 kilobytes? Verifying it was good, just wanted to confirm as cerbios is 256 kilobytes.

it's 256KiB but xyclops_dumper.py only dumps one bank of 4. There's no need to dump it anyway since all retail xyclops chips will have the same BIOS.

[Dark Destiny]

Alright, before I search for the edge of the carped to throw my self from it ....

XBox 1.6 w. Samsung Ram and A-A02 total stock. Flasher is one of those fany cheapos (Tried a couple of em since I have enough of them in case one is dead). 

 

So this is the journey so far.

Tried to flash the xyclops a couple of days ago always ending up Sync failed. But smart is who always does the same hoping for a different result. And so I did.

After a couple of tries doing nothing but the same over and over again this happend

 

Now. a couple of days later, I gave it another shot. Used a resistor and got this fancy new massage...

 

Tried it again just to get the no communication thing over and over again. YAY! So smart as I am (Not really but sound funny here), I removed the resistor and tried again.

That ended up in this (Why it workes now in the setup I startet with in the first place? WTF.)

So yeah baby erase it. And OFC little me is so ready to program it. But then.....

 

So again, same setup like the one I have startet with but now giving me a different result. It seems it erases the chip but then fails to write the bios for what ever reason (Maybe revenge of the xyclops for killing a couple of them, who knows). 

So any idea? My next try would be C4 if I can find some and if not a hammer (Just kidding - Or maybe not...).  

 

EDIT. One strange thing I forgot to say. When removing the resistor I get either no connection or erase failed. By simply putting the reistor on the same pin without connecting it to the xbox it fails at programming as written above.

And some more fun stuff. With a simple switch connectet instead of the resistor I get this :

I beginn to assume that the flasher just sucks badly.

[HarryButt]

IMO those wires are too long

[Dark Destiny]

11 minutes ago, HarryButt said:

IMO those wires are too long

I have put your opinion to the test. Short af wires with the same result. 

 

[HarryButt]

hmm, this may sound weird but add a thicker ground wire from the devices usb connecter to the xbox steal case. The symptoms you have there sound like a buggy connection or EM interference. 

remove the av cables aswell  

Edited May 25 by HarryButt

[Dark Destiny]

Now it starts but then complains about the faster baut rate. Using -s flag result in the same error as above,

Shorten the wires as far as possible and added a massive copper wire which is also pretty short. The programmer literally hangs in the air.

[HarryButt]

I am not the best at explaining things    
use one of the mini USB connectors mounting legs and this wire doesn't need to be as short as the others  

Edited May 25 by HarryButt

[Dark Destiny]

Replaced the awg30 with thicker wire as well. Soldered the extra GND wire to the mini usb leg. It's time this 1.6 faith it's desiny - Become a ram doner. 

 

[HarryButt]

The last thing I can think of is try a UART adapter that has a different chip.

or wait for someone else to chime in with ideas

[Dark Destiny]

Alright. FINALY after some more tries, I got the flashing done. Using 5v and a different location for the soldering. But, I have tried the same yesterday with no luck. Now after changing the point where I have soldered with 5v it worked. Not to sure why but hey.... (She probably heard that I will rip out her rams )

[RetroMyBits]

On 5/25/2025 at 9:50 AM, Dark Destiny said:

Replaced the awg30 with thicker wire as well. Soldered the extra GND wire to the mini usb leg. It's time this 1.6 faith it's desiny - Become a ram doner. 

 

I was taking a look at this post, i have not tried it yet but i'm i wrong or on this picture you have the TXD connected to the same point on the mother board and no RXD ?  I'm going to try this and see if i have any luck. Thanks for the info.