On 20-01-2013, at 9:39 AM, "David T. Lewis" lewis@mail.msen.com wrote:
On Sun, Jan 20, 2013 at 04:52:42PM +0000, Frank Shearar wrote:
At the risk of sounding rather ignorant, what kind of machine would that be? IIRC the 68k machines were big endian but they've been wiped out now haven't they?
It has taken many years of blood, effort, toil, tears, sweat, pointed emails and sharply aimed comments, but finally, finally, my friends, at last we are *free* from the evil of Big Endian! At last we can release our families from the underground bunkers of safety and let them wander the outer world as nature intended.
Most certainly not, Edgar still has one.
Ah, him. Well, I've heard about him and his nasty habits. We're onto you Edgar!
Wikipedia gives a good summary: http://en.wikipedia.org/wiki/Endianness
Older Macs are big endian, and the Squeak VM was originally written on big endian machines. ARM processors can run in either mode. Most likely they run as little endian for Linux, and I'm not sure which mode is used for RISC OS.
I've never yet come across an ARM being used in bigendian mode, but I have to assume some large customer wanted it in order to persuade ARM Ltd to pervert the natural course of things. So somewhere out there are a few million processors yearning to be released from bondage. I take comfort from the thought of the overwhelming majority of the approximately 18 *billion* ARM processors being Properly Ended.
To be honest I really think it's time we considered changing Squeak to use little-endian form for bitmaps, at least. There aren't any major systems out there that use big endian any more. If any legacy devices still need it, they can be adapted to use the same tricks that current little-endian machines have to use *every time* something is displayed on screen.
All I can say is thank goodness that the ATT 'Hobbit' processor never took off, with that insane middle-endian nonsense.
tim -- tim Rowledge; tim@rowledge.org; http://www.rowledge.org/tim The halfway point between right and wrong is still damn wrong. Compromise isn't always a solution