Going through SICP, in the last lectures they are going through register machines, compilers etc.<p>Abelson mentions a for LISP-chip/machine that was more parallelized(yeah spell that) than an ordinary chip.<p>What was the advantage/disadvantage with LISP-based machines?<p>They were more expensive I have heard, but why? Harder to make because they needed more parallelisation or just because there was less demand for them?<p>Are new multicore computers more like LISP-machines were?<p>Some relevant links:
http://pt.withy.org/publications/LispM.html
http://fare.tunes.org/LispM.html
http://www.ugcs.caltech.edu/~weel/lispm.php
http://en.wikipedia.org/wiki/Lisp_machines
This is cool, didnt know of it before:
http://en.wikipedia.org/wiki/Tagged_architecture
The MIT CONS computer and its commercial descendants at Symbolics and
LMI was not a parallel architecture. It was a fairly conventional
uniprocessor CPU which happened to have a register and instruction
architecture that provided some hardware acceleration for typical
"LISP" tasks (specifically tagged pointers: the "pointer" value had a
bit telling the CPU whether to load the value as-is or indirect
through it to load the next value).<p>As for why they were expensive: they were small market pre-VLSI
minicomputers being sold in the late 70's and early 80's. They
competed most directly with machines like the MicroVAX, and weren't
particularly expensive for that market, AFAIK. Assembling and testing
a few thousand ICs into a single computer is just inherently
expensive.
Well, I suppose that the conjunction of a lower demand and a more complex processor (which executed Lisp directly) is a good reason for them to be expensive. The complexity is a problem in the beginning, and if the demand had been higher the prices would lowered, but... I think the main reason of the failure was due to the business side and not the technical merits, unfortunately history shows that technological success has more to do with business skills (i.e., ms) than with the technology (i.e., Lisp Machines, 80's Apples...)
The cost of lisp machines also include much of the cost of developing the lisp machine environment. That probably cost more than the software that came with suns, apollos, etc and the workstations had more volume, so their comparable cost per machine was significantly less.