eMac 800Mhz -> 1.33GHz conversion

[666sheep]

It's OF bug, don't worry. This is the only speed that isn't auto-detected.
Check 1.58 mac mini overclock in Google and you'll find a workaround.
Basically you need to manually type correct CPU speed in OF and save it in nvramrc. Don't remember exact code now, but method is the same as for minis.

Go higher. 1.42 is 1.92 capable (I still have mine).
BTW, you have reminded me this thread and I see now that I've never responded to ravik's question
Forgive me ravik

 

[patriciooholegu]

On Gen2 board it works that way...

1. Everything is warmed up by trickle 5V and standby 12V.
2. Power On button push sensed by PMU controller on logic board.
3. PMU sends a message to the microcontroller on IVAD board (inside silver can) via two I2C wires on a video connector. They are not VGA DDC data link and also used to control CRT brightness, geometry, etc.
4. IVAD microcontroller sends PWRON signal (high) to analog board.
5. Analog board inverts it and makes sure overvoltage signal (PRO) is OK (low)
6. Inverted (low) power on signal (DPO) is sent to logic board via blindmate connector.
7. This gets directly through to downconverter and activates it.
8. the rest of the magic happens

As you can see it involves nearly all available resources to simply power the thing on!
My solution is to just permanently ground DPO on the blindmate connector.

Same logic and signals apply to Gen1 board too.

It seems to be like you are a guru of eMac's guts ibodnar.
So let my ask you something i'm trying figure it out since a few months: Do you know if its posible to isolate the eMac CRT to work as a standard monitor? (So being able to change the logicboard for any standard motherboard?)
Do you know what happens if -without emac's logicboard and downconverter- +5v is sended to the pin labeled "PWRON" on the analog board of this picture:
http://www.lbodnar.dsl.pipex.com/eServer/L-IMG_0677.JPG

"They are not VGA DDC"
Are you shure? Because if it is true, then i'm screwed and run out of ideas. But DDC in any standard motherboard VGA port is a i2c protocol also. What you think it happens if i make a cable to go to IVAD vga signals?

And the most important question: Do you know what is the code of the i2c integrated circuit on the IVAD board? (To look for schematics available).

Oh!, I'm forgetting!: I'm a laptop technician -electronic level- and i have ALMOST all the gear, tools and skills to make this project.
However, not to much experience with CRT monitors, but enough to know the danger, and how to take care about it.
Tanks in advance and please help my on this.
Sorry about my English.

 

[alectrona6400]

I have an Education Edition 2005 eMac that I overclocked to 1.92GHz, but the problem is that the system profiler displays it as 917MHz, and the geekbench score was 337. :/
I am running Mac OS X Leopard 10.5.8 and I have 2GB of RAM in the computer.

 

[Project Alice]

I have an Education Edition 2005 eMac that I overclocked to 1.92GHz, but the problem is that the system profiler displays it as 917MHz, and the geekbench score was 337. :/
I am running Mac OS X Leopard 10.5.8 and I have 2GB of RAM in the computer.

 

[alectrona6400]

View attachment 824111

sorry, i can't let this thread die
i just want some help

 

[iQQator]

2021 - I have two Logic Boards, one is ATI900 and second is eMac2005 1.25Ghz, both worked but...
I wish run one of them without CRT display and power circuits placed in case of worked eMac
Could I find some suitable information about this in one place ?

Thanks for your investigation in this Theme! You cool!

 

[alectrona6400]

2021 - I have two Logic Boards, one is ATI900 and second is eMac2005 1.25Ghz, both worked but...
I wish run one of them without CRT display and power circuits placed in case of worked eMac
Could I find some suitable information about this in one place ?

Thanks for your investigation in this Theme! You cool!

Necroposting aside, I don't know what you mean by ATI900. 9200 or 9600??
There used to be a page that showed you how to run a 2003-05 eMac board headless or without the CRT and analog board. Might make a mirror of that page one day, but I am very busy as of late.