To me this keyboard represents the ultimate in weighted key piano technology. I plug this into my AKAI EIE Soundcard and this then plugs into the computer. Although there is no amplification within the keyboard nevertheless it is rather heavy so at my age I do not really like moving it from gig to gig. 
The sales blurb goes something like this:-
The Roland A-88 Midi Keyboard controller is a portable controller packed full of professional features and functionality, compatible with both Mac and PC.
Roland's A-88 truly breaks the mold when it comes to slim-line Portable controllers, featuring professional weighted action and Roland's renowned Ivory Feel-G keys traditionally only found on Roland's high-end workstations and digital pianos. The 88 Ivory feel-G keys offer a comfortable, moisture absorbent surface creating a realism second to none.
Roland have taken it to the next level when designing the A-88 controller, including the legendary Progressive Hammer Action design with escapement offering the appearance, feel and functionality of keyboards from their flagship ranges, while remaining truly portable. Now your controller keyboard will have a different weighting and feel all the way up and down the board.
The A-88 has easy compatibility with many of Roland’s other hardware, for example their INTEGRA-7 sound module or the JUPITER-50 and JUPITER-80 Synths. For live use, you can play with that grand piano action without the size and bulk, Dual and split layer buttons are even present for instant quick access to layers and zones. The A-88 is also USB bus powered so no power cabling or adapters are required.
The design of the rear panel keeps your studio or road rig tidy, with recessed panels and the ergonomic and easy design of the top panel makes for fast and smooth production as the inspiration arrives. As with the A-49, the A-88 also includes Roland's renowned D-Beam technology for a tactile and expressive control over your performance.
If all of those features weren't enough to get you involved, Roland have also made sure the A-88 has been designed with the Apple iPad in mind and can be connected to the iPad via Apple's Camera Connection Kit.
Streamlined and lightweight, the A-88 from Roland provides not only a portable controller but also a professional weighted, graded and real touch keyboard; a portable keyboard controller that plays like a grand Piano.
