IBM T41 T42 RS232 output trick

[elchip]

Hello to all member's of DK.
After I need RS232 for autodiagnostic and haven't it on my IBM T42 I was look for tipe hov to output it without docking station... And I was spend a lot time tofind schematic diagram of T41 , T42 Apolo 9 mainboard ( Apolo 9 is code name for MB on T41 and T42 ).

Here is what you need :

For all who need COM1 on IBM T41 and T42 it can be put out from Mainboard of laptop.
Look for MAX3243C on MB. It is RS232 transceiver located on MB but it's I/O are
only on dock station connector ( 245 pin HUH...).
I was success output direct from MAX3243C COM1 with cable and work 100%.
U need good solder and time and magnifier too ;-)

Here are PDF files of MAX3243C and laptop schematic of RS232 COM1.
ALso you need to enable COM1 in BIOS setup.
The chip MAX3243C is located on MB bottom on memory socket inside laptop.
You must remove keyboard and inside memory module.
Better disasemble MB of laptop ( if you have time and know to do that...).

IBM T41 T42 RS232 transceiver sch.pdf

MAX3243C datasheet.pdf

ibm t41 t42 rs232 part 1.jpg

ibm t41 t42 rs232 part 2.jpg

If you find is good for you please push THANKS .
Sorry for my bad English.

Best regards to all on DK

[GDB]

I know there are some Dell D620 with Mercedes Stardiagnosis for sell. I have installed Stardiagnosis on my Dell D830. It has a RS232 com port but I cant't get it to work. Is there anybody here maybe that knows the right port setting that need to be done in the Bios ?
Any help is more than welcome

[wiseman]

I have an IBM x41 but have docking station, very interesting read

[boyanab]

Hi, Elchip !
Is the same MAX chip on the X31 tablet's motherboard ?
I can't find it's schematic. Thanks in advance.

[Raceboy]

I have an IBM x41 but have docking station, very interesting read

X41/X41 Tablet has the RS232 chip in the Ultrabase, not in the laptop like T4x series.

BTW, elchip do you have a photo of the finished soldering on the MAX3243 chip?

[makemebad]

Hello i've got MIOZ3 GPS module and I was searching everywhere for thinkpad pinouts to make internal GPS over COM port.

Good job, thank you.

[vionet]

X41/X41 Tablet has the RS232 chip in the Ultrabase, not in the laptop like T4x series.

BTW, elchip do you have a photo of the finished soldering on the MAX3243 chip?

Hi, it's working in my laptop.

[JirkaZ]

elchip: thank you very much, good job.

[DBauto]

What Is the battery life with docking station?

[beblau]

elchip: thank you very much

[Wau Wau]

Nice hack
thanks

i will try it this week
i need it for car diagnostic

[wice]

i need for cardiagnostic too
but i cant understand on what pin i have to solder wires of rs232 connector and on chip ,can anuone help me? sorry on bad english

[malch]

pinouts.serial.jpgt43p serial1.jpgtest.jpg
As the pic shows, there are a bunch of solder pads next to the MAX3243.
This is a pic of a T43P.
The centre hand made drawing is the pinout between the com connector and the solder pads.
[3]TXD is pin 11 of MAX3243
[8]CTS is pin 6 of MAX
[7]RTS is pin 10 of MAX
[2]RXD is pin 8 of MAX

[geser]

Hello
Really good idea!

I've question to whose who ha done the following upgrade.
Have you routed all 9 wires? Or only couple of them?

Thanks.

[malch]

serial2.JPGimg003.jpg

Here is all 8 plus a ground. It would be difficult to route a 9 connector shielded cable inside a T43.
Seems a few have used TX, RX, and ground. I havent tried this mod.