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