EEVblog #418 - Mailbag Apple Newton Teardown - Page 1
Forum section: electronics / general

author: EEVblog
author_rank: Unknown
timestamp: January 31, 2013, 11:06:25 pm
content: Mailbag time.Dave tears down an original Apple Newton Messagepad 100.Dave.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: January 31, 2013, 11:28:57 pm
content: Those 40 bucks are actually Swedish kronor. About $6.Do a giveaway of three of the bags. Either a raffle or a contest. Maybe ask people to specify a reason why they should win. Maybe split them up further if you can bothered, ~250 pcs per prize.Yes, 100% recycled paper. Great for the environment, but don't rip it open in such a way that the stuff flies out all over the place. I did that once.Ord is Swedish for word. Typsnitt means font, so that's a sample of the font Berling Antikva by Karl-Erik Forsberg. It was finished in 1951. This was in the day and age when people still use movable lead types. The other one is actually a fossil of a plant called Murchisonia, or so they claim.

author: EEVblog
author_rank: Unknown
timestamp: January 31, 2013, 11:42:36 pm
content: Quote from: nitro2k01 on January 31, 2013, 11:28:57 pmWhy do you say "claim"?Murchisonia is an Australian plant by the sounds of it:http://en.wikipedia.org/wiki/MurchisoniaDave.

author: Slothie
author_rank: Regular Contributor
timestamp: February 01, 2013, 12:01:50 am
content: Make a diode ROM for your micro PSU. None of this flash rubbish, that's just for noons! While your at it you could make a processor out of 2n3904`s

author: nitro2k01
author_rank: Frequent Contributor
timestamp: February 01, 2013, 12:17:40 am
content: Quote from: EEVblog on January 31, 2013, 11:42:36 pmWell I'm curious how archaeologists concluded it's a plant fossil. Apparently if must be a leave that has dried up and formed a coil. And no, just to get that out of the way, I'm not a creationist or any such nonsense.I couldn't reist to fire up ye ol' Photoshop and doing this after hearing about Davy Jones' Locker. If you want, you could replace the blog header with this for April 1.

author: EEVblog
author_rank: Unknown
timestamp: February 01, 2013, 12:28:02 am
content: Quote from: nitro2k01 on February 01, 2013, 12:17:40 amI assume you'd have to be an archaeologist/botanist to actually know the technical details of it.It wouldn't surprise me if there are only a handful or two of experts in the field that could determine such stuff.Dave.

author: kendonator
author_rank: Newbie
timestamp: February 01, 2013, 06:01:38 am
content: Hey all,It's past midnight here, and I checked EEVBlog and saw a teardown of what I sent in. Totally psyched, I've been waiting three weeks!I would not be surprised if my father took the device apart and made the issue worse, it would not have been the first (or last) poor device to endure his soldering iron... If I find anything else that's really cool in my garage, I'll send it in. My dad was...a collector of electronics. We did have an old typewriter out there (1980's model, too, right up your alley, Dave), Iwouldsend it in, but it is too damn heavy and bulky (something like 10 kg, it would cost a fortune to mail), I decided to take it apart. I'd be willing to send in the boards and actuator mechanism, though.Congratulations on saying my name properly, by the way. You would not believe how many people call me "Kendron" or "Kevin" or "Kendra".My life has meaning, now, Dave Jones has taken apart my Dad's Newton.

author: firewalker
author_rank: Super Contributor
timestamp: February 01, 2013, 08:12:09 am
content: The gLCD was a custom one or a standard model?Alexander.

author: obsoletemac
author_rank: Newbie
timestamp: February 01, 2013, 01:08:06 pm
content: The little springs holding the thick envelope closed are called "jungfruben" in swedish, "virgin's legs".Really enjoyed the Newton teardown, thanks Dave.//c

author: Winston
author_rank: Regular Contributor
timestamp: February 01, 2013, 04:25:38 pm
content: With all of those 1N4148s, you could make a diode array ROM:http://www.oldcalculatormuseum.com/w144romal.jpg

author: deephaven
author_rank: Frequent Contributor
timestamp: February 01, 2013, 09:58:36 pm
content: I made a television caption generator once using loads of 1N4148. Trouble is, they were of questionable quality and I had to replace around 25% of them before I got a clean looking caption. The logic to drive this diode ROM was RTL in TO5 packages.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: February 02, 2013, 05:06:44 am
content: Quote from: mswhin63 on February 01, 2013, 01:00:38 pmThe video quality is fine. If needed, and if your computer can handle it, click the gear icon and switch to 720p or 480p, and optionally view in full screen.And the switch is not broken, but the shaft has U shape in cross section.

author: SeanB
author_rank: Super Contributor
timestamp: February 02, 2013, 06:16:41 am
content: I bought 20k of zeners on an auction once, and still have 15k of them ( gave away 5k) in 2 voltages, 12V and 24V. I use them as general purpose diodes, and they work well as that. Have turned a few into lamps by driving them with 12V from a SLA battery till they glow white and melt apart.

author: bitwelder
author_rank: Super Contributor
timestamp: February 02, 2013, 09:27:00 am
content: On the Newton I noticed most of the chips have a 93XX date marking (and some have also a (c)1993 ), but the two Apple ROMs are marked 9502.A newer 1995 revision for the firmware, while using a ~1.5 years old board?

author: xDR1TeK
author_rank: Contributor
timestamp: February 02, 2013, 01:55:16 pm
content: Hi Dave, I got an idea for the 4148 diodes, build a high frequency voltage doubler, it would be xFactor voltage multiplier.It would be nice to see to what high voltage you can get those up to.Also, though it won't drive much, but it can energize something, wonder what exactly.

author: jancumps
author_rank: Unknown
timestamp: February 02, 2013, 02:06:56 pm
content: Quote from: xDR1TeK on February 02, 2013, 01:55:16 pmThat was my first electronics summer holiday job: build high voltage doublers for a powder paint company to increase the yield during powder painting. When high voltage was applied to the aluminium profiles, the paint powder was attracted to the aluminium, and less powder got lost.

author: xDR1TeK
author_rank: Contributor
timestamp: February 02, 2013, 02:26:09 pm
content: Seems very smart, application specific engineering. Cool.

author: ealex
author_rank: Frequent Contributor
timestamp: February 02, 2013, 03:40:34 pm
content: In the video, at 16:33, then pointing the thermistor: there is a SOT23-3 device marked TR3 that seems toasted - the traces are quite thick - maybe it acts like a switch ?Can you bypass it ? Maybe it will start.

author: nitro2k01
author_rank: Frequent Contributor
timestamp: February 02, 2013, 09:10:31 pm
content: Quote from: jancumps on February 02, 2013, 02:06:56 pmWith 1n4148's? They're typically only rated for a relatively low reverse bias. Those in the video, 70 V according to the pacakging. If they were 1n4148's, how did they stand up to the test?

author: rj2k000
author_rank: Newbie
timestamp: February 02, 2013, 11:33:54 pm
content: I hand-place 400 1N4148 or 1N914s in a product every year. I could use any that are surplus.

author: codeboy2k
author_rank: Super Contributor
timestamp: February 03, 2013, 03:33:15 pm
content: It would be cool to make a DIODE logic computer, and throw in some LEDs at a few key points to act as address and data indicators.You'd have to make the basic building blocks using Diode Logic, AND, OR, NAND, NOR, FLIP-FLOPS, COUNTERS, MEMORY, etc.Have it run a small program that can output a few different phrases, like "hello world" and some such..., the output being shifted through a LED array.might be pretty cool on your office wall.The voltage might be dangerously high to account for the maximum voltage drops...

author: mariush
author_rank: Super Contributor
timestamp: February 03, 2013, 04:40:01 pm
content: Quote from: rj2k000 on February 02, 2013, 11:33:54 pmWith so many components I'd consider moving to surface mount components and maybe even buying a second hand pick and place machine to put the smt diodes on the boards.

author: silicon_ghost
author_rank: Contributor
timestamp: February 03, 2013, 04:58:56 pm
content: I owned a second generation Newton 2100 and loved it. The handwriting recognition was quite good and would learn your style of cursive scribbling.I also wrote some apps for it and the data architecture was phenomenal. It used a loose database structure; I think a record was called a bag and fields were called slots. Every system database was extendable. For example, the base contacts database and app had say 20 predefined fields (first name, last name, city, etc.). Any third party contacts app could add any custom field to any record. The third party app would see the new fields and the base contacts app would not delete or modify the custom fields. Anyone familiar with the Python language today would recognize this as the way classes and objects work in that language. Incorporating this at the OS level was revolutionary.When Steve Jobs came back and killed the PDA I swore off Apple products for a decade. In fact I'm still primarily a Windows, Linux, and Android fan.The reason there is a thermistor in the battery compartment is (at least in the second generation), you could use a custom rechargeable battery pack. I think it was NiMH.Sent from my Nexus 10 using Tapatalk HD

author: xDR1TeK
author_rank: Contributor
timestamp: February 06, 2013, 09:34:22 pm
content: Nexus 10!!!! wooooooooooowi want one

author: NiHaoMike
author_rank: Super Contributor
timestamp: February 07, 2013, 05:26:21 am
content: Quote from: silicon_ghost on February 03, 2013, 04:58:56 pmApple did not kill the PDA. The iPad is more or less a huge PDA, the iPhone is a PDA that has phone functionality built in, and the iPod Touch is really just a PDA. It's true that the name disappeared as it evolved, but it's the same sort of device. It's also true that Apple devices are not as open as the classic "PDAs", but fortunately, Android is very open.

author: hli
author_rank: Frequent Contributor
timestamp: February 12, 2013, 01:40:22 pm
content: The LTC902 is an AppleTalk transceiver. (I found it in a Maxim cross-reference list, which lists it as compatible with the MAX216 - and there are data sheets availbale for this one).There is aservice manualfor the original MessagePad available. It states the model number BO-A300, but this should be the same as the H1000. It also explains what this large ASIC does - and it has a chapter on diagnosing power-on faults (page 31ff).

author: kfitch42
author_rank: Frequent Contributor
timestamp: February 14, 2013, 06:07:33 am
content: Caveat: I am a software guy, so anything I say here might be incredibly stupid...With all those diodes you could make the worlds most ridiculous A2D converterUse an op-amp to boost the input up to a pretty high voltageThen in parallel you have 1 diode, 2 diodes in series, 3 diodes in series, 4 diodes in series ...Each time the output of the op-amp goes up by another diode drop (0.6ish V usually, right?) another string of diodes lights up.To make a n-bit a2d in this way would require (2^n)-1 strings. Using Gauss's summation we see that((2^N)-1)(2^N)/2 = 2^(2N-1)-2^(N-1)So to make a1 bit a2d requires 1 diode,2bit requires 6,3bit requires 284bit requires 1205bit requires 4966bit requires 20167bit requires 81288bit requires 32640

author: EEVblog
author_rank: Unknown
timestamp: February 14, 2013, 07:59:51 am
content: Quote from: hli on February 12, 2013, 01:40:22 pmIt was manufactured by Sharp?Dave.

author: hli
author_rank: Frequent Contributor
timestamp: February 19, 2013, 03:36:11 pm
content: Quote from: EEVblog on February 14, 2013, 07:59:51 amAt least the original one, yes:http://en.wikipedia.org/wiki/MessagePad, though I'm not sure about the MessagePad 2000 series.

author: rain
author_rank: Newbie
timestamp: March 25, 2013, 06:39:38 am
content: Yowza. Is that EMI at the end of the video (~19:30) messing with the camera?

author: haxtormoogle
author_rank: Newbie
timestamp: October 16, 2013, 08:36:24 pm
content: Quote from: rain on March 25, 2013, 06:39:38 amYeah what is up with that video distortion? looks to stop when you hit the power button?On closer look at the video tr5 looks blown.Looking from the service manualtr5 is a major component in the 5V stabilizing circuit. If tr5 is burned out then it will not power on.Would be need to see a follow up on this to see if this really is the problem