PIMOBO
This is an idea that I'm close to taking seriously and going ahead
with, but there are some practical issues that means that it would
probably be too much of a risk. Maybe one day, but probably not.
I like old Thinkpads, and I'm fairly sure that there are a lot of
people who feel similarly. However the Thinkpad that I still use as
my go-to PC is almost 20 years old - chugging along with 768MB of
PC-133 RAM (it recently started getting upset when I had the
maximum 1GB installed), 1GHz PIII, 40GB HDD, USB 1.1, etc.. I'm
resigned to swapping over to a slightly later model soon (should be
working on that now probably), but the later the models, the more
they lose design features that I like from my old IBM-made lappy.
The Raspberry Pi Compute modules are boards that can be installed
similar to RAM cards, slotting into a larger board. It's not a new
concept, but the Raspberry Pi ones are quite well priced and allow
the established software environments for the other Raspberry Pi
boards to be used. Currently there are Compute modules mirroring
major Pi releases up to the Pi 4, for which a Compute module may
(or may not) be in development.
https://www.raspberrypi.org/products/compute-module-3-lite/
Solution: Build a replacement motherboard that fits in the old
Thinkpad, and accepts a Raspberry Pi Compute module. Sell them to
all of the other old Thinkpad lovers. Make millions!
The motherboard would still have to include various support
electronics such as a USB hub to connect up to the USB ports, USB
ethernet adapter, WiFi/Bluetooth adapter, USB adapter for the
built-in Keyboard and mouse (which usually use the PS/2 protocol),
PATA/SATA, audio DAC and amps. Obviously this would be better with
the Pi4 as it has USB3 and one PCIe bus, but the current Pi3
Compute module would still be a serious step up from the original
specs for a Thinkpad as old as mine.
The display would need to be interfaced to, but they generally all
use the LVDS standard, and interfacing that to HDMI has been done
often before:
http://raspberrypiwiki.com/index.php/LVDS_To_HDMI_Adapter_Board
Ideally the battery management interface could be reverse
engineered so that existing batteries can be used and charged.
After-market batteries keep being sold for a very long time online,
so you should still be able to get a new one as well.
Connectors would all stick through the existing holes in the case,
because the motherboard is designed with them all in the right
place.
Ideally future Pi Compute modules would also be compatible, so CPU
and RAM could be upgraded later just by popping in a new card.
Some key advantages:
*Should be much cheaper than the Pi-Top Raspberry Pi laptop kit
(even if you have to buy a junk laptop to convert), while offering
a better general purpose physical design.
*The parallel and serial ports could be connected up to the GPIO
via level converters. I like parallel ports.
*You get a good keyboard, trackpoint, and other IBM Thinkpad
features.
*A 4:3 screen, which I prefer (but others might not).
*Convenient, swapable battery.
*Assembly/disassembly instructions largely already done in the
excellent IBM Thinkpad service manuals available online. Just need
to point at the right sequence of steps from the service manual,
and note anything particular to the replacement motherboard (like
inserting the Pi Compute module).
*Future upgrades just by swapping over the Compute module (though
no guarantee that there will be any, or that they'll be compatible).
But there are also issues:
*The motherboard would have to be specific to one Thinkpad model
among all of the different ones that have been made over time.
Other people would have to seek out that particular model, whereas
they probably have another one in the cupboard that _they_ would
prefer.
*The screen resolution would be limited to the original specs
(which I wouldn't mind, but other people might).
*Serious time required getting the electrical design done (all of
those interface chips to hook up, reverse engineering pin-outs,
battery management, etc.)
*Serious time required getting the mechanical design done - the
replacement motherboard has to match up perfectly with the case, so
I'll have to measure everything perfectly because I don't have the
original engineering drawings. Lots of "oh bugger! That won't
work." moments.
*It will be a fairly large circuit board, so expensive to have made
given my sort of budget.
*Some internal connectors used may be difficult to find or
expensive.
*Assembly and reflow soldering of such a board will probably be
beyond the equipment and abilities that I can cobble togther from
scratch without spending significant money. Due to size and all of
the fine-pitched SMD parts that will probably be required (because
some required chips will only be available in such packages).
*Might need a fair bit of software work to set up everything nicely
in Linux, hopefully don't need any custom kernel drivers though. I
don't really want to know about Windows.
*You wouldn't be able to use the PCMCIA slots, though I might be
the only person to take issue with that.
I can see the first two issues being the big ones, as they could
put off a lot of customers and make it another thing I make that
nobody buys. I think there really needs to be a range of
"conversion kits" to suit different models, but this would multiply
scale of many other issues.
Also even though a Pi4 is powerful enough to rule the world going
by my standards - my old laptop, set up efficiently, does
everything I want at the moment except some Javascript-heavy
websites (where I can't block the Javascript and still use them)
which have finally forced the upgrade - other people complain that
it is only barely, or even not at all, capable of general desktop
use. Absolute insanity to my ears - just set your OS up properly
and use sensibly written applications you idiots! But that's the
market I'd be selling to, and damned if I really want to deal with
it.
With only the Pi3 Compute module as the most powerful one
avalilable at the moment, I guess I'd probably be the only person
happy with its specs. Even if a Pi4 Compute becomes available, this
probably isn't a wise project to pursue, especially for someone who
doesn't like dealing with people (also the reason to rule out
crowdfunding, by the way).
- The Free Thinker, 2020.
Update 2022-03-11:
------------------
Surprisingly it turns out that some Chinese person/people had
already sold some x86-based upgrade motherboards for old Thinkpads,
though later models than the old IBM-made (not just branded) ones
that I like the most:
https://hackaday.com/2018/03/12/new-guts-make-old-thinkpads-new/
More recently they're crowdfunding a second (and more expensive!)
replacement motherboard for the T60/T61:
https://hackaday.com/2021/11/27/replacement-motherboard-brings-new-lease-of-life-to-classic-thinkpads/
https://www.xyte.ch/t700-crowdfunding/
Unfortunately the board designs aren't open-source, so wouldn't
be a shortcut to developing a Pi-compute based mobo which could
be upgraded again later without needing yet more specially made
motherboard replacements. Mind you, the Pi4 isn't really faster
than the original T60 - my plan really applied to the models from
the early 2000s that I personally prefer even more, but really are
too slow for modern web browsing.
