Austin King wrote:

> Greetings Squeakers,
> I am interested in the history of the Squeak 3.8 image.
>
> Metaphorically how much is my Squeak image like sourdough bread?

That's an interesting comparison (especially as I rather like sourdough 
bread...)

>
> Literally, are there instances of objects that have been living ( or 
> allocated ) in the image for 30 years?
>
> I can see how the individual class and method definitions can be 
> traced back, just like libraries in other file based programming 
> languages, but the runtime system of the image seems wholly different.
>
> Was the image thrown away during major transitions in VM such as 
> Smalltalk-72 -> Smalltalk-80 -> Squeak? If not, how is this transition 
> made?

AFAIK the image does descend from the original Smalltalk-80 release 
image which was made available to Apple and others during the initial 
release (1981). Of course, it has suffered some radical transformation 
steps regarding the memory layout of objects (16 vs. 32 bits, object 
table vs. direct pointers) but these did not involve any kind of 
rebuilding from source. Objects such as nil, true and false and some 
parts of the class/metaclass machinery are probably mostly unchanged (of 
course methods were changed or added, but the structure of these objects 
changed very little). It's somewhat ironic that Alan Kay, who urged his 
group to "Burn The Disk Packs" 
(http://www.smalltalk.org/smalltalk/TheEarlyHistoryOfSmalltalk_V.html) 
is using an image which has basically survived from the early eighties 
:-) But I love it that way.

Cheers,
Hans-Martin