EEVblog #872 - Mailbag

Mailbag time!

SPOILERS:
Zifnu Rocket Kit:
Kickstarter:
PAX Instrument T400 Temperature Logger
Arris Cable Modem teardown
Mail from Claire Standish
Sinclair ZX81 Computer Teardown
3D Printed glow in the dark Delorean
Garmin Fishfinder Teardown
Cheap Ebay $9 multimeter teardown
Sharp EL-5810 pocket scientific calculator
Dave's uCalc project.

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[williefleete]

Bigclive did some videos on those death traps. Do not use it to heat coffee, it will make it taste horrible and metallic

[Gabbos]

Poor Sagan, he thought he was going to get a nice treat but got a turd instead. That was cruel of the package sender to trick him that way.

[DrRChandra]

IIRC, the T/S1K had 2K RAM, my ZX81 only 1K. Didn't matter, just about everyone got the 16K RAM pack, which squashed all over the internal RAM (you didn't get 17K or 18K). I think the big difference was, $99 kit, $149 assembled, (virtually) all the other players were $800 or more. So that's why it was my first personally owned computer, affordability.

[AntonyTCurtis]

ZX81 Issue 3 PCB looks pretty professional. The issue 1 PCB I had looked like the PCB traces were drawn by hand. Not any parallel traces.

[SurajGrewal]

that last thing was a water (a electric boiler)....Bigclive did a review on that

[Teth]

We have those Arris modems up in Canada too, they're not too bad. Infinitely better than the Sagemcom trash Ma Bell uses...

Also, Dave, best think I've found for opening boxes is a scalpel. You can pick one up with 15 blades (I recommend #11, it's pointy and reasonably sized) for like $20. Do be careful though, if you haven't used one before, they're sharper than you're expecting.

[genkiadrian]

Dave, in case you're wondering about the thickness of the calculator: Back in the days, Sharp and Casio had a competition who would make the thinnest calculator in the world. Both companies were constantly untercutting the competitor with the thickness and it all ended when Casio released the Casio SL-800 which is, in fact, just 800 micrometer in thickness.

So, your calculator would unfortunately never taken the crown to be the world's thinnest calculator.

For anyone interested, there is an episode of the NHK show "Begin Japanology" which covers this competition under the title "Calculators". It can be found on Youtube and is an interesting documentary for anyone interested in the history of calculators.

[SuperSquart]

yes thats for a battery on the cable modem b/c it does phone 2. so if the power goes out your home alarm can still call out for help

[oregontrailmike]

Sinclair ZX81. Still sitting somewhere in my basement. My first computer! And introduction to Zilog Z80 Assembler... 😂

[PasanKarunanayake]

I don't no why I love the mail bag time soo much. Dave's reviews and gadgets all around the world make the mail bag time so addictive.

[theabsurd]

Bigclive has done a couple of teardowns/videos of those water boilers too Dave, absolutely crazy devices. I think one of them was marketed as a baby bath water heater.

[bulwinkle]

ZX80 and 81 were my first computers. 👌

[WreckDiver]

How I miss my Timex Sinclar 1000....I even had a 32K Memopak for it...my friend had the thermal printer and 32K Memopak. I spent HOURS and I mean HOURS on this thing...sorry...I paid $49 (USD) for it. Absolutely LOVED this thing. I also did Assembly Language on this thing, so you could do more than just "basic" on it.

[AstroSam]

Ahhh... the ZX81. My first Computer! And yes it was crap, but hey, this thing let me start with computers. I was 13 or so, and so i startet programming and learn, how computers works. I loved it :-)

[ziginox]

That Arris box is a cable internet/VoIP modem. The compartment on the side is for a battery. It's required in the US so that the phone system works when the power goes out, especially for 911.

[MarcoMadarco]

Wow! One of my 3DRacers DeLorean car on EEVblog! This is like... wow, Dave, I've made this electronic product and it is thanks to your soldering lessons that I learned to solder the SMDs and the ATMega32u4 QFN!

[aidancurtis]

Dave. The connector on the Arris modem is for a backup battery. It is used in case of power failure as the modem can support VoIP phone connectivity. To call 911 in the event of a power failure the battery is required to sustain the connection.

[gblargg]

10:19 Cable modem with VoIP phone lines and battery backup (I believe that the backup is required for 911 requirements in case power goes out). There's even a battery light on the front to indicate battery status/charge. I've seen battery backups on all Arris cable modems that include VoIP phone lines. It's a throwback to the days when there were real landlines and the battery backup was down the street at the phone company's trunks.

[thephantom]

The Arris is a docsis 2 cable modem with 2 phone lines. The connector is for a 8 hours battery (I forgot if it is NiCD or NiMH) backup for the phone portion. It is also higher quality than standard landline, atleast they claim it to be.

[redtails]

Every time Dave says "Sagan's gonna love that", he means "I will love this, and I'll have the kid next to me to justify my fun" XD