Well, OK, PAPERS really does look very cute. The little wooden
cases and flashing lights are downright adorable. Also, it is hard to
take seriously anything that plugs into a PC's parallel (printer) port.
However, PAPERS is a very serious research project, and these "cute"
aspects are the natural result of engineering design decisions:
The wooden boxes are cheap, easy to make, durable, and readily
customized. They also avoid the cost and complexity of various
The flashing multicolor LEDs also may be cute, but they are by far the
most efficient way to convey status information. The first PAPERS box
used 40 single-color LEDs for four processor status display; using
multicolor LEDs, each PE's status takes only one LED. Green means
running, red means waiting, yellow means running OS code, and black
means no parallel job is active.
The parallel (printer) port doesn't offer much bandwidth, but it is
universally available, can be accessed with less software overhead
than other ports (e.g., SCSI or EIDE), and is thus the standard
interface best suited to low-latency operations sending small amounts
of data. There will be PCI bus PAPERS units later, but they will be
more complex, more expensive, and harder for other universities to
So, yes, the PAPERS boxes look cute, but they are very
The only thing set in stone is our name.