Yea I've used the docking stations and all facets of MPU-401 with different software. It seems it was more designed for MIDI out use. DOS midi inputs have a lot of issues on different hardware. A lot of the time with different software it is completely unresponsive and can only do one key at a time. That's my experience at least. Windows 3.1 seems to have better MIDI control implementation, but there's not much modern dev for music software in that. My advice if you want to play live FM along with trackers is get a yamaha PSS-480 or something. If you're trying to record MIDI composition DOS Trackers are not the best tools. Voyetra or something would probably work better.

Sorry, I'm a little confused here. I was pointing out that some docking adapters provide a Gameport in addition to the other ports. So rather then taping the midi Rx and Tx from the ym715, as discussed above, the signals might be all ready be at the expansion connector. Seems like it would be easier to access them there instead of at the smd chip.
  Of course would still need the opto coupler and resistors for the IO circuit, as per the SB midi cable. The basic circuit is very minimal and if one is willing and able to wire the midi signals from the system board, a DIY SB midi 'cable' should not be too difficult.
  As to the MPU 401 support, if it's no longer in AT2 that kind of limits this discussions. Perhaps there is midi support in one of the other Adlib trackers or a MOD tracker? There are some DOS midi sequencers that might be of interest but that's getting off topic
Yogi

Well you can actually buy the gameport midi cable (mpu-401) on ebay for 9 bucks. The only software you can really use it with is midi out for games or some windows music stuff. There is All Sound Tracker but if you want to use it with OPL3 and Samples and MIDI you will need a SB32. Which were not built into laptops. You can use them independently though on YMF715s. So that'd probably be your best bet until someone writes a better implementation.

A Bump with a new idea.
Depending on your laptop, if you have an expansion connector on the rear of it, the Gameport/midi may be there. It would take some research but if you can find the pin out may be able to tap the midi Rx/Tx from there. Easier then directly at the chip.
Yogi

SYNTH mode is gone in the current version. Sorry, guys!  Note recorder mode FTW

I'd have to dig a bit, but there were a few mods on I-Opener hack sites a while back (the I-Opener was a internet appliance, motherboard and LCD all-in-one with no expansion slots. not quite a laptop and not quite a PC). Some were for tapping the board's ISA signals to add a connector and card.
Here are a few I-Opener sites ( that still work) that have a little info about the YM 719 audio mods:
http://www.mtu.net/~bjcouche/I-O_Audio.htm
http://www.ghettohardware.com/articles/iopener/
http://www.evernex.com/iopener/#snd

True. I've only dealt with some old Thinkpads and a Dell. Working on lappys is a bit like doing origami

Oh don't get me wrong, if there's a will there's a way. But I would have to really think hard to decide if I wanted to take a chance of trashing a an old FM laptop.
  It''s just that for the most part the skill level is too high for most. I just wanted to point out that it may not be 'for everyone'.
  Another option that's not invasive is a RS232 to Midi interface if there is a serial port. Back in the day they were common and can be had on ebay from time to time; there are also DIY solutions also that can built with Midibox hardware ( a Core8, LTC and a IIC slave Midi; happen to be working on a related project now, TK's midi router).

Yea I know the feeling
Yogi

Sorry for the late response

Can you post some links?

I guess it depends on the laptop. I have a Toshiba Portege 300ct and opening this little beast isn't harder than opening a Game Boy.

Come on There are people who change their GB CPU for a SGB CPU.

As you can see from my GBC Bass mod, and GBC Noise filtering mod Im not the best at documenting stuff ;//

While it is doable and have seen similar mods, it is far from simple. I have found that  just the dis assembly and re assembly of most laptops is a major project in it's self, let alone soldering to the pins of the SMD chip. If the pins in question are not used there is little likely hood that there will be a trace or via on the PCB that you could use. So you would have to solder the connections directly to the chip, not for the faint of heart
  If you do jump into this mod, best of luck and please do document it
Yogi

finally somebody answered
I'm asking because I think it's a totally doable thing at least on laptops with the opl3-sax.
You can check in the ymf715e datasheet that the chip has all the gameport signal pins including rxd for receiving midi signals.
So it basically just comes down to connecting a optocoupler and a din socket. I'm quite baffled that no one thought about it.

Without the game port?! You can't use MIDI in DOS unless you have the game port MPU-401 MIDI cable. The AT2 that has MIDI is in an alpha stage as it is.

Has anyone tried the midi mode in adlibtracker on one of those laptops without the game port?