Ask Slashdot: An Open Handheld Terminal For Retail Stores?
Evil Al writes "From the ubiquitous Verifone card terminals to the fancy Apple Store terminals, point-of-sale devices are everywhere. But does anyone know of an open terminal (with printer + Wi-Fi), preferably running Linux, that we can use to run a custom application for retail, made by a reputable manufacturer?"
If you intend to process credit card payments through your custom application on the point-of-sale device, you'll likely fall under the purview of the Payment Card Industry's Payment Application Data Security Standard (PCI PA-DSS), which may require a source code audit and limit what you can have the software do. That may be no problem for you depending on your resources and intended use of your software, but it's worth keeping in mind.
I'll ask the easy question.. WHY?
Seriously, when you business relies on a machine that must work or you are losing money, everyone wants someone to turn to when it doesn't work. That someone isn't a man page or IRC channel or mailing list or whatever support for $foo GPL program here. It's a computer, not a holy war. You press buttons and it does things. When you want a computer you control, you run linux, when you want a computer that grandma can use, you give her a Mac and when you want retail system that checks people out, you run whatever OS that your POS maker asks you to.
AML makes Linux-powered portable handheld computers with Wi-Fi and barcode scanning capability, and they'll give you their source disk with your hardware if you ask, so you can modify it as much as you like if their standard suite of applications don't suit you. You would also need to add a printer like the Epson TM-T88 and an RS232 magstripe-reader like the Unitech MS-240. For the actual card clearing, you'd probably either tie this system into your existing POS mainframe (if you have one) or you'd tie it into an Internet-based POS solution like Authorize.net, or if you are feeling ambitious, you can integrate over SSL directly with a clearing network like TSYS (formerly VisaNet / VITAL). Of course, your biggest expenditure is probably going to be paying someone to write the software to tie all this together for you (unless you can pull it all off yourself, in which case hats off to you!)
http://www.amltd.com/product.asp?pid=m7220
http://pos.epson.com/products/prodsPMOP.htm
http://ute.com/products_info.php?pid=211
P.S.
I have worked on the AML portable computers before. I have not specifically worked with the Epson printer or the Unitech magstripe reader, but both should work in conjunction with the AML unit's WiFi and serial capabilities respectively. You would probably need to custom-make a cable for the magstripe reader since the AML unit uses a non-standard RS232 connector (RJ45 if I recall correctly).