the slowest common transfer method. Early scanners had parallel port connections that could not transfer data faster than 70 kilobytes/second. The primary advantage of the parallel port connection was economic and user skill level: it avoided adding an interface card to the computer. GPIB - General Purpose Interface Bus. Certain drumscanners like the Howtek D4000 featured both a SCSI and GPIB interface. The latter conforms to the IEEE-488 standard, introduced in the mid 1970s. The GPIB interface has only been used by a few scanner manufacturers, mostly serving the DOS/Windows environment. For Apple Macintosh systems, National Instruments provided a NuBus GPIB interface card. Small Computer System Interface (SCSI), rarely used since the early 21st century, supported only by computers with a SCSI interface, either on a card or built-in. During the evolution of the SCSI standard, speeds increased. Widely available and easily set up USB and Firewire largely supplanted SCSI. Universal Serial Bus (USB) scanners can transfer data quickly. The early USB 1.1 standard could transfer data at 1.5 megabytes per second (slower than SCSI), but the later USB 2.0/3.0 standards can transfer at more than 20/60 megabytes per second in practice. FireWire, or IEEE-1394, is an interface of comparable speed to USB 2.0. Possible FireWire speeds are 25, 50, and 100, 400 and 800 megabits per second, but devices may not support all speeds. Proprietary interfaces were used on some early scanners that used a proprietary interface card rather than a standard interface. Indirect (network) connection to a computer During the early 1990s professional flatbed scanners were available over a local computer network. This proved useful to publishers, print shops, etc. This functionality largely fell out of use as the cost of flatbed scanners reduced enough to make sharing unnecessary. From 2000 all-in-one multi-purpose devices became available which were suitable for both small offices and consumers, with printing, scanning, copying, and fax capability in a single apparatus which can be made available to all members of a workgroup. Battery-powered portable scanners store scans on internal memory; they can later be transferred to a computer either by direct connection, typically USB, or in some cases a memory card may be removed from the scanner and plugged into the computer. Applications Programming Interface A paint application such as GIMP or Adobe Photoshop must communicate with the scanner. There are many different scanners, and many of those scanners use different protocols. In