Muli Ben-Yehuda's journal

May 19, 2004

choice quotes from LISP Machine Progress Report

Filed under: Uncategorized — Muli Ben-Yehuda @ 1:24 PM

“The Lisp Machine is a personal computer. Personal computing means that
the processor and main memory are not time-division multiplexed,
instead each person gets his own. The personal computation system
consists of a pool of processors, each with its own main memory, and
its own disk for snapping. When a user logs in, he is assigned a
processor, and he has exclusive use of it for the duration of the

“Each logged in user of the Lisp Machine system has a processor, a
memory, a keyboard, a display, and a means of getting to the shared
resources. Terminals, of course, are placed in offices and various
rooms; ideally there would be one in every office. The processors,
however, are all kept off in a machine room. Since they may need
special environmental conditions, and often make noise and take up
space, they are not welcome office companions. The number of
processors is unrelated to the number of terminals, and may be smaller
depending on economic circumstance.”

“The memory is typically 64K of core or semiconductor memory, and is
expandable to about 1 million words. The full virtual address space is
stored an a 16 million word disk and paged into core (or
semiconductor) memory as required. A given virtual address is always
located at the same place an the disk. The access time of the core
memory is about 1 microsecond, and of the disk about 25
milliseconds. Additionally, there is an internal 1K buffer used for
holding the top of the stack (the PDL buffer) with a 200ns access time
(see [CONS] for more detail).”

“The complete LISP machine, including processor, memory, disk,
terminal, and connection to the shared file system, is packaged in a
single 19″ logic cabinet, except for the disk which is
freestanding. The complete machine would be likely to cost about
$80,000 if commercially produced. Since this is a complete,
fully-capable system (for one user at a time) it can substantially
lower the cost of entry by new organizations into serious Artificial
Intelligence work.”

Oh, just go read the thing already 😉

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