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Greetings from North Carolina

Posted: Sat Jul 08, 2023 8:29 pm
by doug_in_nc
Hi, I just signed up after my NABU arrived on my front porch yesterday. It is now up and running, and has resulted in a my TI99/4A being demoted to wardrobe to make space for it on my desk.

I'm currently trying to improve the "not good" picture quality I get from it and identify how much of the issue is NABU-related, how much is monitor-related and how much is very cheap, totally unshielded composite video cable-related.

Re: Greetings from North Carolina

Posted: Sun Jul 09, 2023 6:23 pm
by RetroJoe
Hey, Doug - welcome from another NABU newbie!

The NABU designers were kind enough to give us composite outputs. Given the original target market, they could have decided to just provide RF.

Composite video should be "good enough" for a 40-column display, so good luck with your troubleshooting.

But, if you get fed up, there is this interesting project going on, that swaps out the NABU's TMS9918A VDP with a pin-compatible FPGA board that has an HDMI output.


FWIW, I've HDMI-ified my Apple //e (with this great bit of kit: ... pple-iigs/) so I am not a retro purist, and might go down that road with the NABU.

IMHO, modernizing video output, storage and comms with contemporary solutions is usually quite cost-effective and makes for a much more enjoyable retro computing experience.... which is kind of the point of a hobby :)

Re: Greetings from North Carolina

Posted: Sun Jul 09, 2023 10:27 pm
by doug_in_nc
Hi Joe

I wasn't expecting 1080p quality video, my question to myself was "why is the video output significantly worse than the other retro computers I have connected through composite to the same monitor?". Changing to another monitor has improved things quite a bit, and using a coaxial composite cable has helped too so It's definitely usable and the text is quite clear now, just multicolored rather than white.

I only have one CRT monitor, and that's monochrome, so it isn't one I would normally use for a machine like this. In CP/M mode with a black background, the image is actually very clear and great to work with, but with a different background color (or rather shade of green), rather than having a uniform background, I get a screen full of sharply defined narrow vertical lines which none of my other computers produce on it.

For text work I am going to make one of the repro serial cards (when the pcb clears customs) and try to hook it up a terminal to run in 80 columns in glorious VGA.