OS9 doesn't like 'mmod' tag in display ICC profiles.

[ssp3]

Since I was doing various display tests with Mac Minis described here,
http://macos9lives.com/smforum/index.php?topic=7048.0
I decided to check whether modified ATI drivers permit the use of display calibration software, and, to calibrate the display under test as a side benefit.

As it turns out, they did and display was calibrated. While results were good, when looking at calibration curves and comparing gamuts, from my experience I knew I could do better. I did several runs, just to be sure, but the results were more or less consistent.

So, in next step, I booted into Leopard and used the same or similar software, but newer versions. I thought, I could use display ICC profiles created in 10.5.8 and, since it is the same graphic card/display combination, move the profiles to OS9 and use them there.

The results did not disappoint me - profiles created in 10.5.8 were slightly better and display even passed the tough UGRA display certification test.

Back in OS9. Placed the ICC profiles to where they belong and, surprise surprise, the Monitors control panel in OS9 do not recognize them!

In spent next several hours "pulling my hair" and tried every tool that I have at my disposal to check "those damn" profiles.
File "type" and "creator" in OS9 - correct.
File name and internal profile neme - correct.
ColorSync utilities in OS9 and OSX Intel all report that there are no errors.
Chromix's Profile Doctor in OS9 and OSX reports no errors.
Some other pre-press profiling tools that can look into ICC profiles - no problems.

Then, upon closer inspection, I discovered that my profiles contained the tag that I haven's seen before in display profiles created by the same software in OS9:

mmod



It is some sort of "Apple display and make information". I couldn't remember which of my tools allow complete removal of ICC profile tags, so I went to hex editor and changed the both occurences of mmod to something meaningless - aaaa.
Moved my profiles back to OS9 and, voila, they are recognized and can be activated!

(That's Mini 1.5 GHz with Dell 22" Ultrasharp, connected by DVI-DVI cable + RockHopper2 Driver, btw.)




So, if anyone in the future will have problems with their display ICC profiles, check whether they contain mmod tag.
If they do, destroy it! In OS9 HexEdit will fit the job.

This tag is not mandatory by ICC specs, so there's no danger in getting rid of it.

[smilesdavis]

do the pictures uploaded get a watermark now?