Computer acknowledges that throughput is absolutely key to performance.
For that reason, we chose not to use the architecture of any existing
desktop computer. The desired performance could be found only in a
computer of a different class: the mainframe.
Having long shed any self-consciousness
about such mundane matters as size and expense, mainframes easily dwarf
desktop computers in the measure of throughput.
This is accomplished by a different
kind of architecture. Rather than require the attention of the main
processor for every task, the mainframe has a legion of separate
Input/Output processors, each with a direct channel to memory. It's
a scheme that works with ruthless efficiency.
The problem for NeXT, then, was not in
finding the proper type of architecture. It was in reducing its bulk so it
could sit upon a desk without crushing it - and in making its power more
The solution was Very
Large Scale Integration (VLSI). This technology allowed the shrinking of
mainframe architecture, with great economy, on two chips. One contains 12
Input/Output processors, each with direct access to memory; the other
contains the circuitry to manage the mass storage.
desktop architecture allows the NeXT Computer to outperform the fastest
PC's and many advanced workstations. In the vital measurement of
throughput, NeXT technology actually comes within striking distance of a
In addition, this drastic reduction in size allowed NeXT
to contain the entire system on a single board (pictured to your
right). Measuring 11 inches square, it incorporates three processors
from Motorola: a 68030 central processing unit, a floating-point unit and
- standard for the first time in a desktop computer - a digital signal
processing chip capable of producing CD-quality sound. All three
operate at 25 MHz. The system board is shipped with eight megabytes
of memory, and is expandable to 16 megabytes using 1 MB Single Inline
Memory Modules (SIMM'S).
On one edge of the board you'll notice the ports that
link the NeXT Computer to the outside world, and to other devices as
well. The MegaPixel Display and NeXT 400 dpi Laser Printer are both
connected here. A SCSI port, with Macintosh-compatible pinout,
allows the addition of various SCSI devices, such as hard disk or
scanner. There are two RS422 serial ports, which are also
Macintosh-compatible, and a thin Ethernet connector (to make use of the
full 32-bit Ethernet hardware built onto the board). There is also a
special port that allows for direct communication with the digital signal
The entire board consists of only 45 integrated
circuits. It is manufactured to microscopic tolerances in a
roboticized factory in Fremont, California - a factory designed and built
entirely by NeXT. Reducing the number of parts on the circuit board
results in greater economy. But even more important, this design
enhances both reliability and ease of servicing.
The system board resides in one of four slots inside the
computer. The other three, though empty, represent an important
commitment by NeXT: Our architecture is wide open for development by the
entire computer industry. In the future, you'll be able to add new
features, from gigabytes of memory to co-processing capabilities, simply
by plugging in an expansion board.