Cash register printing a bill

[Gizm0]

Hello.
I have a problem that I can't solve since a half year.
I have to make a program for a coffee shop, and I already finished the UI, but I can't figure out how to print the bill with the ordered articles via the cash register of the shop.
Actually I don't know much about cash registers, so I'm googling since a half year to find an entry point (a good book or some good code) to this problem, but it's a desert out there.
First of all, does anybody know if cash registers have their own memory, in which they store the daily/weakly/monthly orders in some kind of structure (like a C structure) specific to the cash register, or do they just remember what they have printed during a defined period.
I don't want to mess up something in the memory (if there is memory) because as far as I know there are inspections that check the cash registers in some way,
and the shop would get serious problems if I do it wrong.
The second part of my problem is it to actually print something.
Are there any standards for serial communication with cash registers, or some trivial solutions (like printf("");).
I already found out about "microsoft point of service for .net", but then I have to learn some different languages and then I have to enter the DLL hell, and that's something I would like to avoid, because it gives me cancer. -.-
I'm C, C++, mips assembly and winapi educated.
Can anybody give me good directions how to print via the cash register, without messing up anything?

[Owain]

Well, just like anything else, cash registers vary greatly. Some are simply mechanical, others are small PCs running modern operating systems such as Windows, and many are somewhere inbetween. You cant really write a program which will work with EVERY cash register you will come across, you will have to find out what type of cash register the shop uses and research the specifications of that particular machine.

[Gizm0]

This one connects via LPT port to a normal PC, but I will check the brand and model name for sure.
It seems like you know a bit more about cash registers. :)
Are you able to give me an advice or two if I get all the specifications?

[Owain]

Finding out the type of register is only half the job. You also need information on the printing device. If the cash register uses Windows or some Linux distro then your job is quite easy, because then you just need to look up the drivers of the printer and write a program like you normaly would. As it goes I have never programmed a cash register before but at the end of the day they are just computers, so the bare-bones of it is just the same. What I would do is find out what the coffee shop uses to print bills and then look it up on Google, if its a popular one then you may very well find some helpful information about it. If not, then you could contact the manufacturer. Prehaps they have written an API for their printer?