I've been packing up parcels and sending them to the couriers last few days.
ApologiesFor people who ordered the black GreenAntz v1.9 a while ago, I apologise for delays getting them out to you. They are on their way now. There are a few good reasons why I had to delay.
Progress
Firstly, I found that my USB oscilloscope (Owon) had been giving me some wonky readings because it was underpowered. New laptop I was using didn't give it enough juice. I rectified that with a powered USB hub, but it meant I had to re-do measurements and calibrations, especially the video signal output levels.
While I was there I re-visited the colour signal voltage references and also tweaked the regulated voltage up slightly to make a better match. This required some more research, thinking, probing, tinkering and testing. Things made more sense now that the scope had proper power.
Once everything was worked out and bedded down, I needed to update the GreenAntz units I'd already built, and test/calibrate them all again, often going back and repeating earlier steps until I was satisfied.
Further ImprovementsVideo output is even better again now, especially in terms of colour saturation (brighter, deeper, more accurate and consistent).
Best way to test this is to load up Time Pilot (or similar) and leave it on, let it go through the attract-mode screens (blue-green, green and magenta). Magenta (jets) is the best, as it pushes the video channels the hardest overall (if added together). The background colour should be deep, solid and consistent. No shadows or dark patches. The moving clouds should be bright and prominent, outstanding, not grey and not leaving "shadows". You can test blue by starting a game (the first stage background is a deep blue).
Classic-era games with large areas of solid colour are good for this testing this, such as Wonder Boy and Alex Kidd. You may have another favourite.
Sync Autoswitching - GreenAntz is a bit smarter now - smart enough to not need a switch to select between separate
H + V sync VS composite sync input. After letting various ideas roll around in my head for a few days, I had a flash of inspiration
It now auto-detects when there is no vertical sync, and quietly slips into composite sync mode. The coolest part of this upgrade is that it is straightforward, doesn't need any more or new logic gate ICs or PCB changes, uses a single ubiquitous cheap part, and can be implemented on the existing PCBs - even older GreenAntz units.
If you have an older GreenAntz, an urge to solder, and want to upgrade to sync autoswitching yourself, contact me for simple instructions.
Because the GreenAntz v1.9 units I just shipped already have a sync switch (next to VGA jack), I decided to leave it on rather than make a mess removing it. They have been upgraded - just leave it in the "
V SYNC" position. Future builds won't have a sync switch.
Thank you all for your patience, it will be rewarded
Pics! Back in black, sleek, sexy and always in fashion. There will be a few resistors, maybe a cap, soldered on underneath. These reflect the improvements discussed and they are quite solid, safe and secure, especially once the legs are installed.