As someone who has worked on nonstops for 35 years (and still counting!) it's nice to see them get a mention on here. I even have two at home, one a K2000 (MIPS) machine from the 90's and an Itanium server from a the mid 10's. I am pretty sure the suburbs lights dim when I fire them up :).
It's an interesting machine architecture to work on, especially the "Guardian 90" personality, and quite amazing that you can run late 70's based programs without a recompilation written for a CPU using TTL logic on a MIPS, Itanium or X86 CPU; not all of them mind you, and not if they were natively compiled. The note on Stratus was quite interesting for a long time the only real direct competitor Nonstop had in a real sense was Stratus. The other thing that makes these systems interesting is they have a unix like personality called "OSS" that allows you to run quite a bit of POSIX style unix programs.
My favourite nonstop story was in the big LA earthquake (89?) a friend of mine was working at a POS processor. When they returned to the building the Tandem machine was lying on its side, unplugged and still operating (these machines had their own battery backup). The righted it, plugged everything back in and the machine continued operating as though nothing happened. The fact that pretty much all the network comms were down kind of made this a moot point, but it was fascinating none the less. Pulling a CPU board, network board or disc controller or disc - all doable with no impact to transaction flow. The discs themselves were both mirrored and shadowed, which back in the day made these systems very expensive.
Highsides are unrelated to tankslappers - it is a totally different concept, as discussed in another post. As stated in the article the highside is caused by rear breaking traction and then regaining it while the bike is crossed up, sending you either over the bars or skyward. My own recent highside (6 weeks ago) was caused by an engine seizure after a downchange from fifth in a third gear corner in qualifying. I had the bike leaned over, let out the clutch lever and because of the lean angle the bike rear kicked to the left, grabbed, kicked right and threw me over the bars. Well, so I was told - I do not remember the crash, waking up in the medical centre.
Highsides are particularly nasty, especially if you are knocked out so that you cannot control your crash and get rag dolled.
You can highside by locking the rear, but the common highside you see on track is pushing the rear tire past its limit of traction, while having a heavy load on the rear suspension. As the tire breaks traction, the rear suspension unloads, the tire catches because the force the suspension was putting into the tire is gone and now it only has to support its grip, the rear suspension loads heavily now that the tire has grip and the spring reacts in the way you’d expect. Boing. The yaw angle induced is enough to fling the rider off. I’ve high sided off and then once the bike was free of me it just started riding straight. Happy it was free of the problem.
For relative values of OK - right collarbone/shoulder/4 ribs, right knee ACL (fortunately micro tears, not snapped) and a traumatic brain injury (big bleed). I had lowsided the previous round after losing the front and that was fine, you slide along the track, controlling the fall and slide. In the last one was pitched head first into the track, knocked out and got severely rag dolled.
53, been doing software and hardware since I was 10 and professionally since I was 22. Tried a team lead role a few years ago, pulled the pin after 2 weeks. Don't see any reason why I can't go on for another 10 or 20 years.
In most places I have worked I have been a younger dev, it was only when I started at my new place a couple of years ago that I became one of the 'old boys'. Interestingly most places I have worked seem to have an inverted bell curve for ages, with quite a few grads and then over 40's being the most populous. A lot of the middle ages seem to be in management or lead roles.
Err - what? The whole reason the election has been delayed is because of community transmission in Auckland. Additionally all parties have agreed to the suspension. In fact it was the opposition who called for the intitial suspension.
Some of the answers are close, but no cigar. The main reason for the time delay is the offline authentication of the chip, combined with generation of the ARQC cryptogram. Additionally the EMV protocol is very chatty if there are multiple applications on the chip card, although the latency involved in the customer interaction far outweighs the protocol timings.
As mentioned in many comments online transactions will be an order of magnitude slower, as they need to be sent to the issuer, have their cryptogram verified and the challenge response returned if the card does host authentication - which most do these days.
The entry mode generally does not determine how a transaction is authorised - chip, PayPass (NFC) and stripe can either be off or online. In fact stripe transactions are invariably online unless you want your business to be overrun with fraudsters. One of the prime reasons in the early days of EMV was to have it so safe that offline transactions were fraud proof - or close to. Naturally this noble goal was shot full of holes the moment real fraudsters got to it. However, the card is personalised with various limits and counters and with the possibility of using an offline PIN, which combined with the static authentication does give reasonable protection for low value offline transactions. Fun fact - in the initial spec this offline PIN was communicated between the terminal and the card in the clear. What could possibly go wrong :-). These days it is encrypted.
Anyhow enough blather - hopefully this has given a bit of insight.
What I don't understand is that even when using a German card with multiple applications, online authentication, and online authorisation[0] it's quite fast in Germany – much faster than comparable or even simpler transactions in the US. On the other hand, the very same card is processed even faster when used in Sweden.
The difference is probably faster data connections and more efficient protocol implementations, I would think.
[0]: For some reason receipts here contain quite a lot of information on what happens behind the scenes if you know how to read it. I hope this link keeps working, it contains exercepts of receipts merchants give you here: http://docplayer.org/storage/33/16568026/1498495227/GbAKHYXN... With that information you can e.g. see which steps were perfomed offline.
Does Germany have exactly one financial interchange network?
Living in Canada, I tend to notice a wide variability in the response times of ATMs to withdrawal requests (i.e. the time between when you finalize the transaction request, and when it spins up the bill spitter) and I think the one factor I've noticed it coming down to is the number of interchange networks marked as being supported on the side of the machine.
The ones that just do Interac (the Canadian interbank debit-transaction network) are quite quick; the ones that do Interac and PLUS or Cirrus are slower; the ones that add support for cash advances on plain credit cards by supporting individual CC companies (Visa, AMEX) are slowest of all.
So, maybe it's not the number of applications on the card, per se, but rather the number of applications supported by the terminal, with some sort of O(N^2) interaction between them?
The POS terminals I talk about usually support at least MasterCard, Visa, Maestro, Vpay, and the German scheme Girocard (which in reality are multiple networks in its own). Some even more and they are still much faster than either using the same card in the US or using a US-issued card in the US. I'm honestly quite baffled as to why. I haven't tried a US card in a German terminal yet and neither looked closely at ATM speeds.
I made a screenshot of the most interesting example: http://imgur.com/ye5MJcH This is what they print out for the international schemes. On the left is what the customer gets (sometimes directly on the receipt, sometimes on an extra piece of paper), the right one is for the merchant (some only save it electronically now). Some terminals show less info but much of it is almost always present, something which I haven't seen much internationally in that level of detail.
What is the difference in the actual reader hardware itself ?
That is, what brand of terminal does walgreens use vs. safeway ?
In this late year of 2017 I know that many new NAS devices use cheap processors that make it difficult for them to run rsync over ssh ... it's too computationally expensive to encrypt the data stream at a high network speed.
If NAS vendors make that decision I wouldn't be surprised if some payment terminal vendors make similar decisions ...
> Fun fact - in the initial spec this offline PIN was communicated between the terminal and the card in the clear. What could possibly go wrong :-). These days it is encrypted.
How do you encrypt a 4 digit number (PIN) in a way that is resistant to brute force recovery?
You set up an secure session (e.g. TLS, but you wouldn't do it that way) and send the 4 digit number over it. Or you use any standard cryptosystem with appropriate security guarantees (RSA-OAEP, AES-GCM, you name it).
What you don't do is shove the 4 digit number straight into an ECB mode cipher.
Not true - the entry mode is irrelevant to whether it is batched or online. In fact it is more likely in modern systems to be the other way around. Chip may use offline, including offline PIN, whereas stripe is nearly always online. Source: 30 years EFT Banking experience, specialising in EMV.
When I was doing my 10 year work through Europe thing with my young family I think our favourite time was the 2 lots of 3 months I worked at Bank of Valletta. We lived in an apartment opposite the beach in Sliema.
The island was quiet, the people fantastic and the lifestyle amazing. Even the massive storms smashing the water over the road and ground floor apartments were incredible. We were also there when Etna went up, and had mounds of ash banked against our balcony door.
Although looking at that photo, it looks like there has been more than a little bit of development since were were there in the early 2000s. We left just as they agreed to join the Euro zone, so I suspect the lovely old buses and quaint roads may be gone.
2/3 of Malta's east coast is pretty much a continuous sprawl of villages that have evolved into your typical tourist traps, exactly like what you find everywhere else in the world, with main strips lined with junk stores that sell the exact same mass-produced souvenirs, and sports bars and McDonald's and clubs and big, loud hotel complexes. (Meanwhile, a lot of shady stuff going on in the background. Crackdowns on Italian mafia have seen a lot of organized crime set up their base of operations on Malta.)
If you venture outside of these areas, Malta is beautiful. For me, Gozo (the northern island) is where it's at. Quiet, authentic-feeling, adult, not a lot of tourism. All the best diving spots are there, too. I hope it stays that way and the big developments are constrained to the main island.
That can be true, but then the transaction is considered "fallback" and most issuer Banks that have any brains will be examining these very closely with their real time fraud systems. Some deny fallback outright, but I am not sure if this is within scheme rules, it may depend on the region.
Thanks for this - I was wondering how they got the PIN considering plain text offline PIN has been deprecated for years. My understanding is that the liability shift is in effect for plaintext PINs, but maybe not in the NA/Canada region.
It's an interesting machine architecture to work on, especially the "Guardian 90" personality, and quite amazing that you can run late 70's based programs without a recompilation written for a CPU using TTL logic on a MIPS, Itanium or X86 CPU; not all of them mind you, and not if they were natively compiled. The note on Stratus was quite interesting for a long time the only real direct competitor Nonstop had in a real sense was Stratus. The other thing that makes these systems interesting is they have a unix like personality called "OSS" that allows you to run quite a bit of POSIX style unix programs.
My favourite nonstop story was in the big LA earthquake (89?) a friend of mine was working at a POS processor. When they returned to the building the Tandem machine was lying on its side, unplugged and still operating (these machines had their own battery backup). The righted it, plugged everything back in and the machine continued operating as though nothing happened. The fact that pretty much all the network comms were down kind of made this a moot point, but it was fascinating none the less. Pulling a CPU board, network board or disc controller or disc - all doable with no impact to transaction flow. The discs themselves were both mirrored and shadowed, which back in the day made these systems very expensive.