[LispM-Hackers] Wasting time

Tim Moore moore@bricoworks.com
Thu Mar 28 19:26:01 2002


Thanks for making the source tarballs available; I'm sure I've wasted a
lot of your bandwidth surfing through them.

Speaking of wasting time... I've been contemplating what needs to be done
with respect to the memory systems of e3.  I think that we have no option
but to write a fairly realistic simulation of the VM system and the
Nubus/physical memory map.  All the addresses in the load band are
virtual, and AIUI while the load band starts at address 0 it is not
contiguous.  Furthermore, from some of the dumps I've seen it looks like
there GC related forwarding pointers in there too, so we may well need to
implement the incremental part of the GC algorithm to get into a running
state.

It would be tempting to cheat on the VM implementation, but the startup
code "knows" about the structure of the VM tables and resizes them based
on its probes of the Nubus slot address space.  And that leads to why a
physical memory simulation seems inevitable to me as well: various Lisp
code knows about physical addresses.  Does it do "I/O" (disk
communication, for example) to known physical addresses?  I think we want
to write classes that implement the various Nubus devices, including
memory, and dispatch to them when decoding a physical memory access.

Anyway, is anyone else thinking along these lines or doing work on the
memory part of the system?

Tim

 On 28 Mar 2002, James A. Crippen wrote:

> I made some minor improvements to the web page for no good reason.  I
> also provided tarballs of the Explorer system sources since they seem
> to be popular for snarfing.  Download tarballs, not each file
> individually, if you're snarfing them.
> 
> As another point towards temporal wastage, I was wondering if those of
> you owning Exploders could take pictures of them, perhaps including
> yourselves, for a little photo gallery.  Send photos to me (not to the
> list) as JPEGs, GIFs, or PNGs.  I'll put them up on the website.
> 
> If you feel like just sending a picture of yourself for inclusion,
> even if you don't have an Exploder, that's fine too.
> 
> I updated the table of tested platforms on the web page.  Please send
> me your known platforms and results for inclusion!  I'd like to know
> what other environments people have run E3 within...  And I'm sure
> others would like to know as well.
> 
> 'james
> 
> -- 
> James A. Crippen <james@unlambda.com> ,-./-.  Anchorage, Alaska,
> Lambda Unlimited: Recursion 'R' Us   |  |/  | USA, 61.20939N, -149.767W
> Y = \f.(\x.f(xx)) (\x.f(xx))         |  |\  | Earth, Sol System,
> Y(F) = F(Y(F))                        \_,-_/  Milky Way.
> 
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