Dynamic Resolution Switching for SuperMac Cards

[eharmon]

Various FAQs and READMEs from SuperMac indicate the 3.0 firmware for most of their cards (Thunders, many Spectrums) supports dynamic (rebootless) resolution switching. Which is really handy!

But that's been curious to me, because it's never worked...Monitors always says a reboot is required, or does nothing.

I tinkered around tonight and finally found the magic sauce:

1) You must have the Display Enabler.
2) But Display Enabler versions higher than 2.0 lose support again.

This leaves a pretty slim set of OS versions this seems to work on. 7.5.2 and higher have DE 2.0 built in, and the Display Enabler installers say they only work for 7.1+.

So, I believe that means only the following combinations work correctly:
- System 7.1, 7.1.1, or 7.1.2. 7.5 and 7.5.1 might work.
- Display Software 1.1 or 1.2.

I'm finally able to dynamically switch resolutions!

 

[eharmon]

Specific snippet from the FAQ:

Q: Do the Spectrum cards support on-the-fly resolution switching?​

A: Yes, SuperMac cards support “on-the-fly” resolution switching through the Monitors control panel, provided you have the following: SuperMac ROM version 3.0 or later, SuperVideo 3.0 or later, a multi-resolution display, Monitors control panel v7.3.2 or greater, and Apple’s Display Enabler 1.0 or greater. (If you are running System 7.5 or later, you do not need to install Display Enabler separately). The required Apple software files are part of Apple’s MultipleScan Display software package which is available from Apple for download from AppleLink, eWorld, or via the internet at ftp.apple.com.

But as noted above, newer versions break this again. Another set of cards that suffer from breakage from Display Manager 2.0 I guess!