# automatic teller machine
**URL:** https://boards.straightdope.com/t/automatic-teller-machine/260063
**Category:** Factual Questions
**Created:** [August 16, 2004, 6:46am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063 "2004-08-16T06:46:28Z")
**Posts on this page:** 18
**Page:** 1
### Author:  [@bulldogs\_50](https://boards.straightdope.com/u/bulldogs_50)
#### Post date: [August 16, 2004, 6:46am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/1 "2004-08-16T06:46:28Z")
i’m just wonderin wat backup procedures are used for an automatic teller machine
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### Author:  [@caphis](https://boards.straightdope.com/u/caphis)
#### Post date: [August 16, 2004, 7:34am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/2 "2004-08-16T07:34:15Z")
…what?
I don’t think I understand your question; could you explain better what you’re asking? In the mean time, maybe this will help: [How ATMs Work](http://money.howstuffworks.com/atm.htm).
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### Author:  [@Cillasi](https://boards.straightdope.com/u/Cillasi)
#### Post date: [August 16, 2004, 7:44am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/3 "2004-08-16T07:44:25Z")
> [@bulldogs\_50](#):
>
> i’m just wonderin wat backup procedures are used for an automatic teller machine
Backup procedures? For what? When you access an ATM, it dials your bank and processes your request through your bank. It’s just a middle-machine. It has no liability for the recorded transaction since it’s not approved by the machine but by your bank. The cash in the machine is reconciled against the record of total withdrawals made. If you claim that you withdrew $100 and only received $80, you will only get reimbursement if the machine contains an extra $20, whether the machine is maintained by your bank or by an independent operator.
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### Author:  [@bulldogs\_50](https://boards.straightdope.com/u/bulldogs_50)
#### Post date: [August 16, 2004, 8:10am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/4 "2004-08-16T08:10:04Z")
umm…how are the details of all the transactions stored and if this information goes down and is lost…how is it recovered…are there any procedures that are used?
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### Author:  [@Martin\_Hyde](https://boards.straightdope.com/u/Martin_Hyde)
#### Post date: [August 16, 2004, 8:25am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/5 "2004-08-16T08:25:40Z")
Firstly a receipt is printed that you may take. In general these have a barcode on them, and banks will typically always accept a customer’s receipt as proof of a transaction.
Secondly, every ATM I has used has to be in direct connection with the bank to even process the transaction. I’ve tried to withdrawal from ATMs before and received the message “connection error, come back later” or something to that effect.
So almost always the transaction isn’t stored in the ATM but at the bank in whatever computer system they use to store such things. And I figure the bank’s computers use standard backup procedure to protect this info.
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### Author:  [@Martin\_Hyde](https://boards.straightdope.com/u/Martin_Hyde)
#### Post date: [August 16, 2004, 8:26am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/6 "2004-08-16T08:26:48Z")
> [@Martin Hyde](#):
>
> Secondly, every ATM I **have** used has to be in direct connection with the bank to even process the transaction. I’ve tried to withdrawal from ATMs before and received the message “connection error, come back later” or something to that effect.
:o
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### Author:  [@Brutus](https://boards.straightdope.com/u/Brutus)
#### Post date: [August 16, 2004, 9:41am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/7 "2004-08-16T09:41:41Z")
> [@bulldogs\_50](#):
>
> umm…how are the details of all the transactions stored and if this information goes down and is lost…how is it recovered…are there any procedures that are used?
Tape backup back at the processing center. But don’t expect a bank to do a restore job for a transaction at a ATM, unless there are subpoenas and whatnot involved.
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### Author:  [@bulldogs\_50](https://boards.straightdope.com/u/bulldogs_50)
#### Post date: [August 16, 2004, 11:06am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/8 "2004-08-16T11:06:20Z")
if any one is familiar with the terms full backup (grand father, father, son) and partial backup (differential, incremental), could i be assisted in a breif explanation of wat backup procedure banks use to help the recovery process if atm transaction receipts, data etc is lost
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### Author:  [@Brutus](https://boards.straightdope.com/u/Brutus)
#### Post date: [August 16, 2004, 11:27am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/9 "2004-08-16T11:27:11Z")
> [@bulldogs\_50](#):
>
> if any one is familiar with the terms full backup (grand father, father, son) and partial backup (differential, incremental), could i be assisted in a breif explanation of wat backup procedure banks use to help the recovery process if atm transaction receipts, data etc is lost
No offense, but why so curious about transaction receipts? I contracted at a bank several years ago, and am fairly well versed in how the bank handled it, and a bit less well versed in how the ATM processing services (Cirrus, etc) handled it, but it’s just an _odd_ question. The pin numbers aren’t recorded at any stage of the process, you know! 🙂
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### Author:  [@bulldogs\_50](https://boards.straightdope.com/u/bulldogs_50)
#### Post date: [August 16, 2004, 11:34am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/10 "2004-08-16T11:34:56Z")
> [@Brutus](#):
>
> No offense, but why so curious about transaction receipts? I contracted at a bank several years ago, and am fairly well versed in how the bank handled it, and a bit less well versed in how the ATM processing services (Cirrus, etc) handled it, but it’s just an _odd_ question. The pin numbers aren’t recorded at any stage of the process, you know! 🙂
lol soz for even asking!! ive been doin work on backup procedures for various things but i cant find out wat atm’s use…so if ne1 has the answer that would b great
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### Author:  [@cantara](https://boards.straightdope.com/u/cantara)
#### Post date: [August 16, 2004, 12:54pm UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/11 "2004-08-16T12:54:23Z")
I’ll try to give you some info, although a lot has been given above…but I’m afraid I can’t do it in teen-text-speak, d00d…
The ATMs are already connected to the network for their financial institution (FI). When you access the ATM, your card ID and PIN number are sent directly to the FIs mainframe. The PC that is the front-end for the ATM is strictly there to display the pictures on the screen and to transmit and recieve the data from the mainframe. The authentication and authorization is performed at the mainframe and the determination of the funds to which you have access are performed centrally. This is how you can go to any (of your FIs) ATMs to get an updated balance. When you withdraw the money, then electronc transaction is debited from your account and the mainframe tells the ATM how much to dispense.
The backups are performed at the mainframe. Typically backups are performed on the databases on a nightly basis. Depending on the FI, the number of transactions, and the technology they are employing they may run a full backup every night, or a full backup weekly and incrementaly backups on a daily basis. If a problem occurs during the day, there are specific systems in place to recover the data that has not been backed up yet (DB2 logs, redundant disk, etc)
Banks have many systems that require special processing on a nightly basis and backups tend to be done first, so they may occur between 9PM and midnight.
Also note that the backups are needed to ensure that the FI has a full copy of all the data for that system. If you have an inquiry about specific activity or that you have been debited twice for the same transaction, then that will be recorded in some sort of transaction log for your account. The FI won’t (usually) go back to take a look at the data that was backed up for resolution.
If a problem occurs with the PC living inside the ATM, then it will shut itself down and requires a maintenance call. The FI can tell what ATMs are online and if any of them are having problems. If it has a problem after the OK has been given to dispense cash and the machine goes down, then it will be unable to return your card and you will have to contact the FI directly.
Does that help?
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### Author:  [@gotpasswords](https://boards.straightdope.com/u/gotpasswords)
#### Post date: [August 16, 2004, 10:05pm UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/12 "2004-08-16T22:05:26Z")
The closest an ATM gets to maintaining a backup is the internal audit record - generally printed on paper tape like a cash register receipt - listing date/time, account/card number and $amount in or out.
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### Author:  [@Mr.Slant](https://boards.straightdope.com/u/Mr.Slant)
#### Post date: [August 16, 2004, 11:17pm UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/13 "2004-08-16T23:17:54Z")
The internal audit record is an option, too. Not every ATM will have one.
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### Author:  [@CC](https://boards.straightdope.com/u/CC)
#### Post date: [August 16, 2004, 11:19pm UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/14 "2004-08-16T23:19:24Z")
[QUOTE=cantara
Does that help?[/QUOTE]
If it doesn’t, I vote the OP can’t be helped. Talk about arcana!
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### Author:  [@bulldogs\_50](https://boards.straightdope.com/u/bulldogs_50)
#### Post date: [August 17, 2004, 6:31am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/15 "2004-08-17T06:31:53Z")
> [@cantara](#):
>
> I’ll try to give you some info, although a lot has been given above…but I’m afraid I can’t do it in teen-text-speak, d00d…
>
> The ATMs are already connected to the network for their financial institution (FI). When you access the ATM, your card ID and PIN number are sent directly to the FIs mainframe. The PC that is the front-end for the ATM is strictly there to display the pictures on the screen and to transmit and recieve the data from the mainframe. The authentication and authorization is performed at the mainframe and the determination of the funds to which you have access are performed centrally. This is how you can go to any (of your FIs) ATMs to get an updated balance. When you withdraw the money, then electronc transaction is debited from your account and the mainframe tells the ATM how much to dispense.
>
> The backups are performed at the mainframe. Typically backups are performed on the databases on a nightly basis. Depending on the FI, the number of transactions, and the technology they are employing they may run a full backup every night, or a full backup weekly and incrementaly backups on a daily basis. If a problem occurs during the day, there are specific systems in place to recover the data that has not been backed up yet (DB2 logs, redundant disk, etc)
>
> Banks have many systems that require special processing on a nightly basis and backups tend to be done first, so they may occur between 9PM and midnight.
>
> Also note that the backups are needed to ensure that the FI has a full copy of all the data for that system. If you have an inquiry about specific activity or that you have been debited twice for the same transaction, then that will be recorded in some sort of transaction log for your account. The FI won’t (usually) go back to take a look at the data that was backed up for resolution.
>
> If a problem occurs with the PC living inside the ATM, then it will shut itself down and requires a maintenance call. The FI can tell what ATMs are online and if any of them are having problems. If it has a problem after the OK has been given to dispense cash and the machine goes down, then it will be unable to return your card and you will have to contact the FI directly.
>
> Does that help?
this has helped alot. thanks heaps
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### Author:  [@bulldogs\_50](https://boards.straightdope.com/u/bulldogs_50)
#### Post date: [August 17, 2004, 6:32am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/16 "2004-08-17T06:32:55Z")
> [@gotpasswords](#):
>
> The closest an ATM gets to maintaining a backup is the internal audit record - generally printed on paper tape like a cash register receipt - listing date/time, account/card number and $amount in or out.
thankyou too…this will also help me
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### Author:  [@Atticus\_Finch](https://boards.straightdope.com/u/Atticus_Finch)
#### Post date: [August 17, 2004, 7:10am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/17 "2004-08-17T07:10:49Z")
Why does the OP spell “what” as “wat”? It’s in a number of his posts, so I assume it’s not a typo.
Is this some new (d)evolution of L33T speak? I don’t think I got that m3m0.
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### Author:  [@Princhester](https://boards.straightdope.com/u/Princhester)
#### Post date: [August 17, 2004, 7:31am UTC](https://boards.straightdope.com/t/automatic-teller-machine/260063/18 "2004-08-17T07:31:44Z")
> [@Cillasi](#):
>
> If you claim that you withdrew $100 and only received $80, you will only get reimbursement if the machine contains an extra $20, whether the machine is maintained by your bank or by an independent operator.
Actually this isn’t true. But the bank asked me not to spread around why they agreed to give me my missing $50 even though there was no extra $50 at the end of the day, because otherwise they’d be shelling out to every lying sod who’d heard how you do it.