I've got X 4.1 working on a 1200 running (more or less) Woody. The hardware is probably similar enough that you can use some of what I've found.
Note: the 1200's video hardware is very different from the 500 and 1000. Tips and tricks that work for those models will probably screw things up.
My 1200s are mono, and I have stripped down the XF86Config file to reflect that. I was hoping it would speed up the X startup by not messing with unsupported modes, but it doesn't seem to have helped much.
Here are some extracts from my configuration that may help you:
Section "Monitor"
Identifier "LCD0"
VendorName "Builtin"
ModelName "Monitor Model"
HorizSync 30-35.5
VertRefresh 60-70
Modeline "640x480" 28.32 640 656 752 800 480 488 490 529 -HSync -VSync
EndSection
Section "Device"
Identifier "Card0"
Driver "neomagic"
# I got the BusID from a message that the neomagic driver spit out
# during an unsuccessful initialization when it was set to "ISA"
# (left over from the ST1000 setup). I don't know whether it's
# right for all ST1200s.
BusID "PCI:0:20:0"
EndSection
As the comments say, that BusID may not be valid for 2300s, color units, etc. The line might also be unnecessary: it was included (and set to "ISA") in the sample file for a Stylistic 1000 that I used as a starting point.
Section "Screen"
Identifier "Screen0"
Device "Card0"
Monitor "LCD0"
DefaultColorDepth 8
SubSection "Display"
Depth 8
Modes "640x480"
EndSubSection
# Commented out for ST1200 mono without external monitor
# SubSection "Display"
# Depth 15
# Modes "640x480"
# EndSubSection
# SubSection "Display"
# Depth 16
# Modes "640x480"
# EndSubSection
# SubSection "Display"
# Depth 24
# Modes "640x480"
# EndSubSection
EndSection
Are you going to be using the stylus? If so, see the notes at:
http://www.the-labs.com/Stylistic/1200.html
about setting up the serial port. And note that, for X version 4.x, you need to use the "fpit" driver, not "xf86fpit.so".
Here's the section for it:
Section "InputDevice"
Identifier "mouse1"
Driver "fpit"
Option "Device" "/dev/ttyS3"
Option "BaudRate" "19200"
Option "MaximumXPosition" "6250"
Option "MaximumYPosition" "4950"
Option "MinimumXPosition" "10"
Option "MinimumYPosition" "10"
Option "InvertY"
EndSection
Those calibration values are not very good, but trying the ones suggested by fpitcal made things a lot worse. You'll probably have to do some experimenting if you want really fine control over the cursor. I'm hoping that it'll be feasible to adapt a calibration app from one of the PDA Linux suites to the Stylistic, but haven't looked into it yet.
I'm still in the middle of getting the configuration dialed in. I'll post more when I'm happy with it.
Ran