[Vm-dev] New Window VM (Closures, FT2Plugin, Large Cursors)

John M McIntosh johnmci at smalltalkconsulting.com
Sat Mar 7 19:23:43 UTC 2009

Ah, I have a bias opinion for an answer, but I'll not discuss that here.

However the BIG issue for the 3.8.x and earlier series of macintosh  
carbon VM is their behaviour for opening a closure image.
What you will find is that if you attempt to open a closure image the  
squeak.app will start then terminate
It will print a diagnostic message to the console which you can see  
via Apple's Console.app found in Applications/Utilities.

07/03/09 11:11:51 AM [0x0-0x8d08d].org.squeak.Squeak[1894] This  
interpreter (vers. 6502) cannot read image file (vers. 6504).
07/03/09 11:11:51 AM [0x0-0x8d08d].org.squeak.Squeak[1894] Press CR to  

The reason for this behaviour is that 15 some years back John Maloney  
coded up the version checking logic and  there was a question
what to do now. At the time CodeWarrior under os-7.5.x would helpfully  
put up a dialog window if you printed to the *console* and did
a getchar for the answer, that code has moved forward for years now  
and no-one really has tested until now.

Interestingly the getchar on os-x does not block and returns null and  
we terminate the VM, but the behaviour is confusing if you don't
understand what is going on.

I will at some point push out a 3.8.22 VM that should put up a more  
helpful dialog message, but people who have older VMs underfoot
should realize this behaviour should be an indication that perhaps  
your VM is too old.

On 7-Mar-09, at 8:12 AM, Andreas Raab wrote:

> Bert Freudenberg wrote:
>> John bumped the Mac VM's major version to 4 to signify closure  
>> support. Maybe the other platforms should follow suit?
> I figured v4 would signify the Stack VM or later as this VM will no  
> longer be able to run v3 images. The current set of VMs are fully  
> backwards compatible so I consider them logically to be v3 VMs.
> But I'm willing to reconsider if people prefer the v4 terminology.
> Cheers,
>  - Andreas

John M. McIntosh <johnmci at smalltalkconsulting.com>
Corporate Smalltalk Consulting Ltd.  http://www.smalltalkconsulting.com

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