Apple //e Video Tweak Avoids Color Killer Mod

During the break I spent some time playing with my Apple //e, recently set up after some 25+ years of neglect. Last year I replaced the PSU mains cap (common failure) and explored the excellent Apple ][ Disk Server and the Game Server – who could have imagined the cassette port transferring at 9600 bits per second! I didn’t have a joystick, which ebay has since solved, but given my vision I won’t be making any high score tables.

The //e is connected via composite video to my Samsung 27″ monitor/TV. I was very disappointed with the clarity of text, 80 column mode was unreadable even with the monitor on maximum sharpness. I remembered a far better display on the tube tele in the 80s.

The computer has a “text mode” switch on the motherboard. This cleared it up, but I don’t want a monochrome //e. I also noticed the monitor did give a clear picture for one second when I connected the video signal.

I figured I was suffering from chroma signal bleed through, forcing my monitor to interpret the signal as colour, and I’d need the color killer mod. This seemed confirmed by the picture clearing up if I snubbed out the PAL colour chroma oscillator with my finger.

My //e is a PAL version and I played with the 2 PAL chroma pots which adjust the background tint as a side effect of balancing the colour signal. I noticed they had no effect in text mode. Yet the text was equally blurry in text or mixed text/graphics mode.

Before the mod, I decided to at least set the chroma trimpots properly (for a black background in graphics mode) and I also tweaked the chroma frequency capacitor trimmer (this affected the moire patterns but not much else). I did this in mixed text/graphics mode with some text at the bottom.

To my surprise, as I approached the optimal position for the two chroma trimmers, the text sharpened up better than it had ever appeared on this monitor.

More importantly, in full text mode, it still looked great, as well as in 80 column mode and even 80 column + graphics. The chroma pots were still having an effect in text mode, even though the background colour didn’t reflect their setting.

I suspect that balancing the chroma signal properly prevents some noise reduction system in the monitor from kicking in, leaving a full bandwidth display in both text and graphics modes. In graphics mode the individual colour pixels are distinct, the best I’ve ever seen a PAL Apple ][ do (having never experienced a pure NTSC set up, let alone RGB).

So now no color killer mod needed.

Firefox 35 Custom High Contrast Fix

As I wrote in my last post, I’ve been compiling custom XUL.DLLs for a number of Firefox releases to get around the ridiculous restriction that if you are running Windows in High Contrast mode, then ALL WEB PAGES WILL BE DISPLAYED IN HIGH CONTRAST MODE,  making the “Allow pages to choose their own colors” check box broken and useless. Honestly who thought this was a good idea, clearly not a visually disabled person! What would have been wrong with detecting HC mode, asking and turning OFF the “allow pages to choose…” option, with a way to stop it asking? Or a least the current arrangement with a power user string to disable it.

After some futzing I found my custom compilation/fix only works if XUL.DLL and MOZJS.DLL from the custom build (of the Firefox 35 release source code) are copied, a little strange as I am using Visual Studio 2013 which is used for the Win32 releases now, but probably due to a different config.

In following up fixes to this issue, I found Firefox 37 has fixed it using a 3 way option picker. I would have stuck with the nightly release but the Custom Colors toolbar button that I use to toggle colors isn’t compatible with the new setup. That’ll need to be fixed by the time 37 is released.