Let's talk about the 760...

[Dant]

Recently, I have come into the possession of a Thinkpad 760XD, which will be my first Thinkpad!

Whilst is it relatively "obsolete" today, I quite like it. It's decently compact, doesn't weigh too much, has a nice keyboard, the display has just the right pixel density, and it can play my large library of games I've bought on GOG.com just fine... and of course the built-in capture card is freaking awesome!

So, I of course want to restore it to not merely working, but the best possible condition I can bring it to. Currently, all I need to make it functional is a floppy drive to boot from, and I am looking at CompactFlash cards and adapters to replace the hard disk.

I'm not going to waste the time and experience of those on this forum answering questions that have already been answered (especially by Bill Morrow himself, and ozzymud, the curator of http://conradshome.com/thinkpad/resources/), rather I want to explore questions that haven't really been asked: Can the CPU be upgraded beyond the 166MHZ MMX P1? What's the ideal dock? (Selectadock 1,2,3; Dock I, Dock II?)) How well do PCI devices run in these docks? (Enough for a Voodoo 2?) Does the MWave do a decent job as a SB clone? All of these among other questions, of course.

Basically, some rather specific hardware questions, that have general answers.

Some links from around the forum, that I found relevant to this topic:
http://forum.thinkpads.com/viewtopic.php?f=6&t=107908
http://forum.thinkpads.com/viewtopic.php?f=6&t=97393
http://forum.thinkpads.com/viewtopic.php?f=6&t=95394

[Medessec]

The 760 is pretty high up there for being one of my favorite Thinkpads, and you've got the 760XD, which is the best of the 760s. It's a great first Thinkpad if legacy hardware does you just fine.

I don't have much info on doing a CPU upgrade, but since you already have the best... only possibility I think would be doing a reseat/resolder job.

I'd imagine the Selctadock III is the one you want. The earlier Selectadocks are... earlier, and the others are just port replicators, not bespoke docking stations. I have no experience with actually using one though-so you'll have to wait for someone else to hear about how devices work in them.

I have a CF adapter somewhere... I've tried it out before on a G-series. But be aware that unless you're using FAT with an old Win 9x operating system, CF cards are far less accustomed to running a full-on OS.

[Dant]

Well, being a bit of a Retro PC gaming enthusiast, legacy does quite well!

The 760 uses an MMC-1 module for the CPU, which contains the 430TX northbridge, the L2 cache, and (of course) the CPU itself. MMC-1 CPUs in the P1MMX range go up to 300MHZ, which ran at the same FSB clock, and (in some cases) the same voltage as the 166 in the system already, so I see no reason for thermal issues or incompatibilities. Also, there were Pentium 2 MMC-1 CPUs (think TP770) but compatibility across the northbridges is intriguing.

Interestingly, I found this: http://www.tomshardware.com/forum/61621 ... piron-mmc1. Which seems to be proof positive that the 440BX's Northbridge, and the 430TX's Southbridge are not necessarily incompatible... Looking at it now, if a similar process could be done to a 760, we're looking at cramming maybe a 366MHZ P2 into one... Likely with thermal issues, though.

Given all I intend on running being Win9x, and lightweight versions of linux, I think the power-savings cost-effectiveness of the CF card is worth it.

[Medessec]

Ah whoa. Looks like you've been doing your homework. Weirdly I've never commenced a CPU upgrade before, it does mean tracking down some interesting old hardware.

I'd appreciate any trackings of success you have, I have a 760ED that's just sitting at the moment... I might do something with it, but I've never gotten around to it. My G41 suits my 16-bit needs perfectly well for now.

I would be careful- I'm sure you know what you're doing but I remember last time I took apart a 760, it was literally a 3D puzzle. Because all the computing gubbins are tucked behind the modular parts in the back 1/4 of the laptop, and I'd imagine any thermal issues would become immediately problematic due to how tightly put together the thing is.

I do agree it seems you can get a pretty fair power boost with little risk provided it's installed properly.

[Dant]

Yes, just looking at how the mainboard is put together brings visions of some 3D cube puzzles into my mind.

An update, I think I have found the reason for this strange southbridge compatibility:http://en.wikipedia.org/wiki/PCI_IDE_ISA_Xcelerator

It would appear that the 440BX and the 430TX used the same southbridge the entire time, the PIIX4M!

However this endeavor seems to have been made a bit more difficult...

The 166Mhz Pentium MMX in the 760XD runs at a Vcore of 1.8V, whereas all of the MMC-1 Pentium 2s run at a 1.6 Vcore... The good news is that the Pentium 2 should run, ironically, cooler than the CPU that came stock with the system. The bad news is that if the MMC-1 module doesn't have it's own voltage regulation, which I think it does, it'll kill itself eventually through overvolting.

Now, really, comes the questions of BIOS incompatibility and the resulting new memory controller possibly adding to the maximum possible RAM... Only experimentation will tell, and I may want to cross reference the 770 bios with the 760XD bios with a hex editor sometime.

[Dant]

Sorry to double post, but after doing further research, I can now confirm that Pentium 2's will not work in a 760 series Thinkpad, due to the CPU not being MMC-1. 166mhz is the best we can get out of it. =/