What I would like to know is why they can’t patch the 32-bit programs to fake it in the 64-bit OS? I mean the 32-bit that they need is there in the OS. It would seem to me the only problem is that the 32-bit plug-in couldn’t access more than 2GB of RAM. No big deal. Probably the more important question is why didn’t Microsoft design the current 64-bit OS to have a fake 32-bit mode for programs that needed it. They could have then removed it in 3 to 5 years when everyone has moved to 64-bit. But, then my next question has to be why is it taking plug-in developers so long to get 64-bit versions out. 64-bit is the future and that future is coming fast. When places like Dell start selling $700 computers with 64-bit OSes the future is now.
Rant mode off.
Robert
I, and many others who know more than me, have thought about this problem quite a bit. As you may know already, a technique known as "thunking" allowed just the kind of switching you are talking about, between 16 and 32 bits. It seems reasonable to extend this concept to 32 versus 64 bits. But it ain’t so simple.
One of the problems is that no switching between 32 and 64 bit mode is permitted within a process. If this were solved, there is still no guaranteed way to convert a 64 bit address, or integer value for that matter, to an equivalent 32 bit address or value. It is not surprising that the Photoshop folks did not provide built in support for older plugins.
Historically, developers have been forced to leave Macintosh legacy plugins high and dry several times, relying on the customary willingness of the Mac customer base to upgrade to new hardware. Plugin developers had to port from the 68000 to PPC architecture, then again for PPC to Intel. In addition, there are the various development platforms within OSX, one of which (the Carbon and Cocoa split) is the reason for the lack of a 64 bit Mac Photoshop.
One of the mostly unsung virtues of Windows is that, unlike the Mac, customers have been able to run the same plug-ins since Photoshop became available for Windows in 1996. With 64 bit, this long party seems to be drawing to a close, but it’s not over yet.
Besides, we developers haven’t given up on 32-64 bit thunking, and a third party solution may finally turn out to be possible.
