Take it off!
The MessagePad 120 is relatively straightforward to open up, either for simple repairs or just to satisfy nerdy curiosity — PDA Soft provides a clear set of take-apart instructions.
Back in the mid-1990's, however, snap-in wiring connections were more rare than they are today, so breaking an opened-up MessagePad 120 down into its constituent parts requires some soldering-iron dexterity, a skill I don't possess.
So here's my 120, merely opened up, and not fully disassembled — I didn't want to risk murdering my old friend.
Lying face down with its bottom removed, the battery bay (right) and PCMCIA card slot (left) dominate the MessagePad 120's main circuit board. Note that board-component spacing and layout is rather relaxed when compared to that of current handhelds.
Remember that DIN-8 serial port and speaker from a few pages back? Here they are again, en déshabille, flanking the MessagePad 120's seven-volt power input.
The rear-facing infrared port uses a 1.5-by-1cm mirror to bounce the signal up to two horizontally mounted IR sensors and down from its one IR emitter.
When running Newton OS 1.3, the MessagePad 120 had 4MB of ROM; when upgraded to OS 2.0, that ROM doubled to 8MB. These two Apple-branded chips, unlike any other of the 120's circuitry, ride on the handheld's bottom cover. I wouldn't bet my 'Pad on it, but my presumption is that they're the 120's OS-housing ROMs.
The two (ROM?) chips in the previous photo, mounted on the 120's case bottom, interface with the main circuit board mounted in the case top through the two sockets on the right and left of this photo.
As mentioned above, Apple offered an optional NiCad Battery Pack for the MessagePad 120, which was charged through — what else? — an optional MessagePad 120 Charging Station, which was simply a dock into which you could slip your 'Pad or battery pack. Contact was made through two external pads, which then led through the bottom of the 120's case (left) and made contact with small pads on the the circuit board (right).
Next page: 'This is the end / Beautiful friend'
In a way this was _far_ more advanced than the iPhone/iPad
Back then, they actually thought about making a pen-based users interface. For example as far as I have seen, you could just write a name anywhere and select it to get the address of the person behind it. It actually tried to do more with the computer than just emulating physical devices.
That first false dawn
As it happens, I went to visit Apple on a fact-finding mission as the Newton team was being disbanded, and interviewed leading players. I was looking at different systems; the focus wasn't Newton but General Magic's "Magic Cap." We looked at a number of other systems too, focusing on PDA and mobile media technologies.
Magic Cap pioneered the approach that Apple used with iPhone - building a community of network operators. It showed promise, but it was seriously flawed, and the dead hand of operator control had the inevitable result.
At that time, Microsoft's abysmal WinCE was both confident and victorious. It was puny, unimaginative and annoying but it leveraged Windows and Office. But it always looked like the past, not the future. It wasn't good, it wasn't loveable, it was just there. Newton had the glimmers of loveability, but the tech was flawed and Apple just didn't _get_ networking.
I love the way that Apple has re-invigorated the smartphone world. To me, iPhone and Android look like today - they capture the best of what was already forming all those years back. But I'm still waiting for something that looks like tomorrow, and I have a suspicion that neither Apple nor Google has the vision for the jump from lean and useable touch OS to something truly new.
I'll stick with my Psion, thanks.
As an Amiga user, I resent being called an Amigo. Some (most?) of us prefer being called Amigans. Stop trolling the commentards, please :)
Just as the MP120 disappeared, we saw the launch of the US Robotics (Palm) Pilot - I knpw this date because the diary on my Palm phone starts in July 1996. Owing a massive debt to its chunky predecessor, it had three huge advantages:
 Form factor - it would slip into a shirt pocket. The real test of a PDA is: "have you got it with you, right now?" - the Newton was too bulky and heavy to pass this test, more like a modern netbook or iPad.
 Handwriting recognition - Newton's system was a great idea, but neither the software nor the processing power were up to the job. Effective handwriting recognition remains a significant challenge for today's PCs. Palm selected Graffiti, which isn't true handwriting recognition since it requires the use of stylised forms for letters, but minimised the processor requirements.
 Simple, out-of-the-box synchronisation with Windows - so that losing your PDA was no longer a world-ending event like losing your Filofax, and content changes made on your Pilot were reflected on your PC (and vice versa).